Optical device for spatial manipulation of objects
The device includes a source of optical radiation, an optical system, the spatial movement of an object in the environment associated with the optical system and/or with a mobile table, additional optical unit located after the main optical system, the settings of this unit is correlated with the parameters of the optical system. The radiation source is made continuous and entered modulator intensity of the radiation, or the radiation source is made of a pulse. Additional block secures the distribution of radiation in the environment surrounding the object, and includes a lens or system of lenses, or other optical element. The wavelength of the optical source and the optical parameters and the composition of the medium provide absorption of radiation in the environment, time and energy parameters of the optical source provides the creation of thermal or thermal and acoustic gradients in the environment around the facility, sufficient to spatial fixation in a given volume or movement in a given direction. The distribution of light energy in the environment surrounding the object may be in the form of a single light spot, or narrow rectangular strips, or lines, or arcs of okrainetz, and the array of particles regardless of the optical properties, weight and dimensions, including their fixation in a predetermined position and movement in a given direction. 22 C.p. f-crystals, 9 Il.
The technical field
The invention relates to the field of technical physics with a wide range of possible applications in chemistry, electronics, optics, materials science, nanotechnology, biotechnology, pharmacology, biology, medicine, theater, advertising and concerns the manipulation of the spatial position of objects of different types from single cells and biomolecules to metal and dielectric particles in gases or liquids.
Known quite numerous devices for manipulatie separate objects with the help of mechanical devices such as the micropincers., forceps, microneedles, etc., a Disadvantage of such devices is the need for mechanical contact with the object. In the case of small samples with characteristic sizes of the order of units of microns manage them with the help of such devices is difficult. Thus there is the danger that my" to the surface of the tool due to different physico-chemical effects. Especially critical these problems for the case of working with micro-objects type of individual cells or biomolecules.
An alternative solution for fixation and positions of the various objects is the use of different types of radiation from the ultrasound to the laser. The greatest progress was achieved with the creation of the so-called “optical forceps”, the principle of which is based on the effect of light pressure. This effect provides for the formation of optical gradient forces holding the irradiated particles in a field of highly focused radiation from a laser operating in a continuous single-mode regime [1-3]. Example managed particles can serve as a transparent dielectric spheres in the size range from 20 nm to tens of microns, and biological entities such as viruses, bacteria and cells. These devices produced commercially  and widely used in various fields of medicine and biology, however, have certain disadvantages and limitations. To create sufficient restraint gradient forces requires the use of strong focusing of the laser beam using microobjective with a large aperture, which dramatically walco to transparent objects with refractive index, greater than the refractive index of the environment. Thus, it is not possible to manipulate particles having a refractive index close to the refractive index, or highly absorbing or even completely opaque to radiation of objects. The necessity of using strong focusing of radiation directly to the sample leads to the formation of a sufficiently high intensity (up to 5-10 MW/cm2), which can lead to unpredictable effects on biobyte related heat or photodynamic effects until significant damage. This effect is somewhat reduced, but not completely eliminated, by the use of lasers in the near infrared range (700-900 nm), where the majority of biological molecules has minimal absorption. Moreover, optical gradient forces are very small (unit piconewton), which imposes restrictions on the ability of manipulating transparent particles, only small size, not more than a few tens of microns. Moreover, the method is intended for manipulation by a single particle, i.e. it is not possible to simultaneously manipulate multiple particles or with high concentrations in the environment. what lasaosa radiation particles is implemented on the basis of gradients of temperature or pressure, induced in the particles due to the absorption on high-power pulsed laser radiation. In one of these methods proposed for cleaning various surfaces, separation of dust particles from the surface is achieved owing to a sharp thermal expansion of the irradiated particles . In another method of asymmetric laser ablation of a particle its anisotropic irradiation (for example, only with one hand) leads to a rapid thermal evaporation of part of the particles or formation of a plasma torch and, as a consequence, to the formation of the recoil effect, as in jet engines, which causes the particle to move in the direction opposite to the direction of ejection of ablation products . The movement of individual parts of the object, possibly due to the formation of quasi-hydrostatic pressure in the liquid under the influence of absorption in her laser radiation. In particular, in one of the technical solutions of the laser light through the hole in the solid sample, done by the same laser was directed into the sample and due to the strong hydrostatic pressure entering the inside of the sample liquid, the sample was split into separate parts, which were scattered in different directions . In another decision, the laser radiation is emitted at high speed through a small hole in the bounding volume of the vessel wall . In another device, the laser is first used to cut samples and end-stage area nedorezannye" small jumper is directed laser pulse of high energy, providing a final separation of the parts of the sample, which in this case due to pressure fly with great speed (catapulters) . A shortcoming of all the optical methods and their different modifications [10-13] is the need for direct irradiation of the sample or part of a high-intensity radiation, which can lead to changes in its properties or damage. In addition, the use of these methods on the proposed schemes allows to provide only a large initial acceleration of particles, that is the question of the retention of these particles or fine manipulation of their spatial position, including targeted slow movement in any given direction has not been solved. In addition, these methods do not allow to manage multiple particles.
From this lack of free methods based on the energy use of ultrasound (US) for the movement of particles [14-17]. However, these methods require accommodation near the particle source is an example, in the line of the piezoelectric elements. All of these methods are relatively complex and require careful synchronization of the individual sources or move them to transport particles, which imposes certain difficulties in their practical implementation. Moreover, in these methods, it is difficult to provide high precision manipulation of particles due to the technical complexity of an acoustic lenses for the formation of the short wavelength of the ULTRASONIC vibrations.
The closest in technical essence is the solution [18-19], which offers optical forceps for manipulation of the reflecting objects. In the first invention  is focused radiation, including on the edge of the particle, when captured and a little edge region adjacent to the sample. As the radiation source using the laser in a continuous mode, which creates a gradient force due to the described effect of light pressure. That is, these forces are not thermal or acoustic nature, and the environment around the object is not fundamentally necessary. Since these forces are repulsive, not restraint, as in the case of transparent particles with a higher prelo the SQL high-speed scanning of the laser beam around the particle. The disadvantage of this scheme is the complexity of the technical implementation, requiring, in particular, additional scanning mirror. Technically it is easier to use at the same time three bundles, which are evenly spaced around the perimeter of the particles . To implement this scheme it is possible to use known methods of splitting a single beam into multiple, including the use of diffractive elements. However, this scheme has many of the already described disadvantages of each optical forceps, including direct irradiation of the sample, a little restraint forces, the inability to manipulate transparent particles having a refractive index close to the refractive index of the environment, and opaque particles with strong absorption and relatively large size.
The purpose of this invention is the elimination of the above drawbacks, i.e., the ability to manipulate the spatial position of individual particles, and the array of particles, including their fixation in any given position, their movement in any direction with any speed, and the particle does not impose strict requirements as optical properties (they can have any index of refraction, to be C the particles, that excludes the possibility of radiation damage.
This objective is achieved in that the device for optical manipulation of spatial position of objects in the environment that includes a source of optical radiation, an optical system, the spatial movement of an object in the environment associated with the optical system and/or with a mobile table, which may be an object, a source of optical radiation of a selected operating in CW mode and to modulate the intensity of this radiation is introduced additionally modulator optical radiation associated with a specified source. An alternative solution is the choice of the radiation source operating in a pulsed mode.
In addition, introduced additional optical unit located after the main optical system, and the parameters of this block are interconnected with the parameters of the optical system. The specified block is made so that a desired distribution of radiation in the environment surrounding the object, and includes a lens or system of lenses and/or apertures and/or spatial filter, and/or holographic elements, and/or diffractive elements and/or interference elements, and/or the how many of flexible optical fibers, and/or various combinations of these elements. The wavelength of the optical source and the optical parameters and the composition of the medium is chosen in such a way as to ensure the absorption of radiation in the environment. Time and energy parameters of the optical source is selected on the basis of conditions for dynamic generation of thermal and/or acoustic gradients in the environment around the object, which, in turn, directly or through related effects provide a force on the sample, sufficient to move it in the desired direction at a given speed or fixation of the object in the correct amount.
Proposed parameters specified additional optical unit be chosen in such a way as to ensure that the environment surrounding the object, the distribution of light energy in the form of a single light spot, and/or narrow rectangular strips (lines), and/or circular arc, and/or in the form of polyserve, and/or in the form of a light ring around the object, and/or in the form of a continuous light spot with the intensity of the radiation, decreasing towards the center, and/or in the form of a light ring around the object, and/or in the form of a light ring in the center of which there is a separate light spot, and/or which are composed of separate light spots, and/or strips and/or polycarpou, arcs, circles, and/or their various combinations.
The specified optical unit can be made in the form of cylindrical lenses, and/or oval lenses and/or one or more optical plates with adjustable angle of inclination relative to the optical axis of the main optical system, and/or various combinations of these elements.
Offered between the secondary optical unit and the object to introduce additional optical elements placed in the environment near the object. These elements can be an optically transparent to the radiation plate, or a similar plate, but with an absorbing coating on the surface facing to the object, or similar to the first plate with additional absorbing film on a given surface, or only one absorbing film, so that the plane of these elements oriented perpendicularly to the optical axis of the specified block.
To effect the object proposed to use the technique of acoustic lenses in which to generate acoustic waves using laser radiation. Next to the object is the acoustic lens, oriented in space t is output or the output of the lens surface applied absorbing coating. Additionally, for the case of sources with continuous emission provided by the introduction of unit changes the frequency of modulation of the radiation intensity associated with the primary modulator. In the case of using a pulse of radiation in the function specified block is changing the repetition frequency of the optical pulses. These frequencies determine the corresponding frequencies (wavelengths) of acoustic waves acting on the object. The frequency change is necessary for the spatial movement of the object due to the spatial shift of the focus of the acoustic lens, the position of which depends on the frequency (wavelength) of acoustic oscillations. An alternative solution is the introduction of block mechanical movement of the lens associated with the lens.
It is also proposed to combine separate acoustic lens in the range, and the optical system to do so, enable the formation of multiple light beams, each of which falls on the corresponding lens. In addition, you enter a block of phase delay, coupled with each of the lenses and the light source. All these measures are necessary to ensure the operation of the line acoustic lens mode phase of the acoustic antenna.
As the first unit and the optical system. This unit can be designed as a beam-splitting plates, and/or diffractive elements and/or optical fibers, oriented in space so as to provide separation of the primary light beam on the several other at least two light beams. In turn, these beams can be oriented at an angle relative to each other and the magnitude of this angle lies in the range from 1 to 180°. In particular, the beams can be directed at a right angle or towards each other. In the latter case, the beams can be positioned coaxially and Pets misalignment their optical axes so that they are parallel shifted relative to each other. The positions of the foci of the individual beams can be the same, lying in the same plane or to be displaced along the optical axis relative to each other.
It is also proposed due to the choice of parameters of the secondary optical unit, agreed with the main parameters of the optical system, to ensure the environment around the object three-dimensional distribution of energy in the form of a single cylinder, and/or a concave lens, and/or areas with an object inside of this sphere, and/or two intersecting cylindrical beam with the object within the area of their intersection, the/or their various combinations.
To create the necessary volume of spatial distribution of radiation is proposed along with the selection of the appropriate parameters of the optics introduction of additional sources of optical radiation with independent main optical systems and optical blocks.
One of the possible applications of the present invention is the manipulation of objects within the various tubes. For practical implementation, it is proposed to use a tube with an optical transparent walls. The optical system provides for a specified distribution of light energy within this tube, and the orientation of the light beam relative to the optical axis of the specified tube may be perpendicular or parallel (aligned). In such schemes provides for the use of different spatial configurations of optical beams, in particular beam with a planar geometry, perpendicular to the specified axis of the tube, two flat beams, between which the object is located, and/or beam cylindrical geometry of the optical beam, and/or their various combinations.
For the possibility of manipulation by the movement of the object along the axis described above tube features introduction the Kim way to ensure that the cylindrical geometry of the light beam with a cross section in the form of a ring and an independent Central part. Additional modulator is designed to provide intensity modulation only in the Central part of the light beam, independent of the modulation of the peripheral annular part. In the case of using a pulse source function specified modulator boil down to time management and energy parameters of radiation only in the Central part of the beam.
Additional optical unit can be made also in the form of optical fibers, which are fixed in space with additional holder so that the fiber end was near object. In the holder provided additional device for moving the holder along with the fiber in any given direction. It is also possible to use multiple fibers with different spatial orientation of their distal ends around the object from the line to the location on the circle or on the surface of a sphere around the object.
Also provides the option of applying on the side of the fiber absorbing coating or fixing it pogasli on this concave surface is absorbing the radiation of the floor. To the end of the fiber can also be docked acoustic lens with an absorbing coating on the flat input surface or the output of the concave surface.
A typical version of the technical implementation of the invention is the manipulation of objects with the use of microscopes, including inverted optical scheme.
The object in this case is located between the cover glass or the top, only on the optical transparent substrate. All of these elements are located on a standard mobile table for precision position control, which is possible using the joystick.
Pets option, when the optical system together with an additional unit provides light energy distribution around the object, which is partly in contact with the object in one or several border areas, including touch around the perimeter of the object.
In all of these embodiments, the medium can be used with different properties and composition of absorbing the radiation fluid, and/or solutions of liquids and/or gases and/or mixtures of gases, including air, and/or gels, and/or biological environment, and/or various combinations thereof. In particular, the Pets scheme, to the x tissues or individual cells, and as the object used medication and/or capsules with the medicine, made for example in the form of liposomes, and/or various microneedle type polystyrene microspheres with attached biological elements, and/or different fluorescent probes, and/or thermal behaviour of the sample in the form of chemical compounds, various metal and non-metallic beads, and/or their various combinations.
In the case when the source environment does not absorb radiation or absorption is so weak that you cannot create sufficient to manipulate objects gradients of temperature and pressure, the required level of absorption in such environments can be provided by including in the composition of the medium absorbing component of different nature. These components can be delivered in the field of manipulation of the flow of gas or liquid, and these streams can be served from the respective additional blocks as continuous and discrete time, i.e. separate portions. Pets, in particular, the use of the aerosol stream. Special blocks to generate respective streams may have different spatial arrangement with respect to the optical buckaloo beam and different spatial geometry of these flows from cylindrical to flat.
In addition to the manipulation of objects in the volume of gas or liquid media the invention also allows them to control on the surface of various solid bodies, for which the optical system together with the additional optical unit provides the specified distribution of radiation in the environment in contact with the surface of these phone as an example, solids can be mentioned semiconductor and optical materials, and tasks accordingly, the object management nanotechnology, microelectronics, biotechnology, chemistry, biology, medicine, etc.
As the radiation source includes a variety of radiation sources, including lamps and LEDs with an emphasis on lasers. Use of lasers operating in CW mode, which is modulated in intensity by using the corresponding modulators (mechanical, optical, electro-optical, acousto-optical and other), in a wide range of frequencies from a few Hz to hundreds of MHz. It also assumes the use of sources of pulsed radiation with a pulse duration ranging from 10-3up to 10-15sec. If necessary, enter additional unit connected to the e is. As such sources can be used by many well-known gas, solid state, semiconductor lasers and dye lasers operating in continuous wave and pulsed modes, including pulsed nitrogen laser, semiconductor lasers in the near-infrared range, neodymium laser (first and second harmonic), holmium and erbium lasers, laser sapphire, ruby laser, carbon dioxide laser with a maximum range typical for selected laser wavelengths.
Thus, the proposed device differs from the prototype in a number of features that allows us to reach a new goal related to the manipulation of the spatial position of the different particles, regardless of their optical properties without optical damage. The main difference between different variants of optical forceps is that the light is not used to create a gradient optical forces due to the pressure effects of the light itself, and to create a thermal and acoustic gradient, periodic, whose action on an object causes the latter to move. In all variants of optical forceps, one of which is used as a prototype, uses only continuous lasers without having a pulse repetition with the required frequency, and the sources of continuous radiation, which is modulated in intensity to create a periodic thermal and acoustic waves impinging on the sample.
A source of acoustic gradients can be many physical phenomena, including absorption, electrostriction, optical breakdown plasma generation, coherent Raman scattering, etc., (see, for example, ). The most versatile and does not require significant energy cost is photoacoustics effect arising due to the absorption of radiation and the subsequent dramatic expansion of the radiated volume. The resulting volume changes and the displacement of the heated layer leads to the formation of large mechanical forces, which significantly accelerate small particles in the vicinity of the laser beam, so that they can fly even a few meters . The pressure near the focused laser pulse, for example, when the optical breakdown in water at a pulse duration in the picosecond range can be substantial, up to thousands of atmospheres . But for the purpose it is sufficient to have a much smaller pressure adjustment which is achieved due to the smooth variation of enerdata speeds until fairly small. The propagation of acoustic waves and associated acoustic flows, and their subsequent effects on biological object sets it in motion under the action of forces as acoustic pressure, and is involved in the motion of the acoustic mikropotokami. Achieved temperature in the region of absorption can also be low - level-tenths of units of degrees Celsius. In principle, this level of temperature does not damage biological structures. Moreover, the proposed device, the temperature gradients are formed not in the object itself, but close to it, so they can't directly influence. In the prototype is also used continuous wave power up to hundreds of mW, which with a strong focus directly on biological object (a cell, bacterium, etc.,) in many cases can alter its structure, until his injury.
One of the features of the present invention is the use of intermittent radiation flux, forming a periodic action of pressure gradients. The most effective mode of generation of pressure by using pulsed radiation in a wide range of durations from milliseconds to picosecond resulting pressure is relatively high. However, the pressure may be generated by modulation of the power of continuous radiation in a wide frequency range from a few Hz to several MHz. From the point of view of a reasonable compromise between the efficiency of conversion of light energy into acoustic and simplicity of the technical implementation of the preferred ultrasonic frequency range is approximately in the range of 10-50 kHz.
Thus, the laser in this solution is used to generate ULTRASONIC vibrations, which can be used later in the schemes that are close to "UZ clutches" [14-17]. Creating using microoptics systems light distribution close to the geometry of the micro sound lenses will allow for the formation of ULTRASONIC oscillations with very small wavelength, theoretically even smaller than the wavelength of light. The advantage of this method for the generation of ULTRASONIC waves is the ease of spatial displacement of the source of generation of these oscillations in an optical image of an acoustic lens, which deprived purely acoustic system of generation of ULTRASONIC waves. Thus, in accordance with predlagaemye schemes you can create "photoacoustics tongs", which, depending on the ratio of the acoustic constants of the particles Boo the ka in the surrounding part of the environment and the positive particles), or, conversely, to push the particles, if the difference is negative. An example of the first particles are light polystyrene beads or individual cells, an example of the same second are metal balls. Most simply be created using cylindrical optics photoacoustic lenses, although the creation of concave spherical lenses should not encounter fundamental difficulties. In particular, it is possible overlapping of the two cylindrical lenses with mutually perpendicular axes. In the case of strongly absorbing medium is quite easy to create an acoustic lens on the surface of the liquid due to the spatial light intensity distribution in the cross section of the beam, for example, with the minimum intensity in the Central part.
It is interesting to note that, in principle, possible to use and unmodulated continuous wave, which by virtue of heating the liquid can lead to thermal convection in the vicinity of the laser beam. These microconvection threads may be involved in the movement enough light by small particles. This is especially easy to implement when the vertical location of the optical beam with cylindrical geometry in which the heat flow will raise the particles would the sky waves appearing in "the walls" of the cylindrical beam. However, due to the high overall associated heating the liquid it may be unsafe for biobjective.
The nature and direction of the acting forces on the sample of the acoustic pressure depends primarily on the nature of the distribution of the absorbed energy around the sample.
In the present invention the force gradient pressure will in most cases push the particle, and not to extend it. Therefore, for fixing the spatial position of such particles, push forces of acoustic pressure, requires the creation of acoustic gradients, discretely distributed or evenly around the particle.
In this case, you can use an already known solution for forming multiple beams of light around an object, at least three, or continuous ring, which was previously proposed for optical Cheptsov [18-19]. Such schemes, for example, on the basis of diffractive elements or systems of the individual optical elements may, with minor modifications, be used here, producing, however, completely different in physical nature and mechanism of effects with other light sources and their modes, that is, which is analogues using, for example, thermal effects to remove particles from the surface of the substrate , is that in the present invention thermal gradients are created near a single object in the absence of direct exposure of interest. Thus, it does not require contact of the latter with additional surface. The award also similar to the radiation is exposed to the object itself, and you want his contact with the substrate to abrupt thermal expansion of the particles induced by the laser radiation, helped to create the acceleration to overcome the forces of cohesion of the particles with the substrate (van der Waltz, electrostatic, chemical, etc). To overcome the need to use significant energy laser pulses, leading even to melt the metal particles. Thus, in similar and other similar devices on the proposed schemes cannot be controlled by the position of the particles and, in addition, the proposed acceleration mechanisms require high energy, damaging the object.
To create acoustic waves in the present invention is used, the effect of the absorption of radiation in the environment directly surrounding the object. In relation to biology and medicine as has a relatively low absorption at the level of 10-3cm-1but nevertheless sufficient to generate significant acoustic effects when using laser radiation sources . In addition, it is possible to use lasers as UV range (nitrogen, excimer, etc.,) and IR (solid-state, neodymium, holmium, erbium, and others), where the absorption of water and other solvents few more, but they still remain transparent for observation of the particles in transmitted light. As optical schemes can take advantage of the numerous existing solutions implemented in inverted microscopes, as well as commercially developed optical Siptah  and laser systems microcassette of biological samples and their ejection .
Even in the simplest case with a single light beam focused near the object, it is possible to control both the speed and roughly the direction of movement of the particles by moving the relative position of the light spot around the object. Thus the supply of energy can be carried out using an optical fiber. The latter can be used as a traditional device for the mechanical contact manipulation of the particle in the absence of radiation, and in the E. In the case of source selection with a strong absorption in the medium acoustic waves are generated directly at the output of the fiber, because the radiation is absorbed in the small region adjacent to the end of the fiber. In the case of relatively weak absorption to generate the desired acoustic waves is used or absorbing coating on the end face of the fiber, or at last put a special highly absorbent tip.
It is more convenient to control the motion of the particle when focusing radiation using a cylindrical lens in the light spot in a line or using a special oval optics in the spot in the form of a sickle. Fixation position is achieved, as already mentioned, due to the creation of light distribution in the form of separate spots or rings around the particle. In this case, the radius of such distribution may vary depending on the size of the particles or even a few particles that can be captured together. At the moment of capture radiation can be turned off, and the position of the light spot can be determined with additional pilot beam, for example, from a semiconductor laser or light emitting diode in the visible range of the spectrum. Such a scheme is useful for managing frequent the microscope. With a larger distance between the glasses, that is, if you need to operate in a three-dimensional volume, you must use two beam directed at an angle to each other. Volume capture particles depends on the angle between the beams and the minimum in mutually perpendicular orientation of cylindrical beams. The intersection of these cylinders will create a zone in the region of intersection, in which the intensity is absent or minimal. The particle is captured by a peculiar light trap walls which constantly emit acoustic pulses, and moved in the desired direction. Optionally, the docking of one particle with another in point of convergence of a particle in a light trap with the other particle radiation for a short time off in order to allow the particles to come into contact, as when the radiation of the second particle can build acoustic pulses from the nearest part of the light trap. Then one such trap can hold two or more particles inside neobychainogo volume, including a large number of particles with a high concentration in the environment.
Create two-dimensional or three-dimensional temperature distribution in the environment, nepremicnine compounds and drugs. For example, this way you can control the position of a small capsule, in particular liposomes, with medication within even a single cell. The creation of temperature or acoustic gradiate in the environment will allow you to control the transport of drugs in tissues and to direct it in the desired area (the target). One of the additional mechanisms of such control is the dependence of diffusion coefficient on temperature, i.e. in this case is implemented by thermal diffusion.
It should be noted that in the present invention there are no strict requirements to the quality of the optical beam, as you want to create essentially only thermal gradient near the particle. In addition, quite small Pets irradiation of the particle wing of a light beam, whose power is much less in comparison with the distribution of radiation near the center of the light spot. Estimates show that for the case of simple enough light biological objects and energy parameters of the radiation will be less than the same laser parameters, already widely used in optical light Siptah. This means that in the present invention, firstly, no danger of damage during accidental radiation SIRENIA the irradiation of only a small area of a particle near its borders, and, third, it is possible to combine the present invention with existing optical forceps. In the latter case, the proposed scheme will need to provide only the additional modulation of the laser beam. Control the motion of the particle due to asymmetric thermal expansion of only a small exposed part of the surface has the advantage compared with known similar solutions [4, 9] (see above), as the impact is not detrimental, and it is possible to smoothly adjust the direction by changing the position of the light spot on the perimeter of the particle.
Thus, the possible mode when the radiation is directed only at the edge of the particles, which due to the small heating and concomitant expansion effects or radiation pressure moving.
For convenience of operation and determine the position of the light spot of the radiation can be entered in a test beam of the visible spectrum, shared with the main beam. This scheme is useful when the initial alignment in the absence of operation of the primary source, or when the radiation visible to the eye, for example, when it is in the infrared or ultraviolet region specfically because of the possibility to control the position of any particle in the absence of a specific requirement of their optical properties, and the acting force, and therefore, the magnitude and velocity of the moving particles can be quite easy to adjust by changing the energy parameters of the used sources. The most suitable laser sources, although in principle can be used and the usual sources, including lamps, which can be easily integrated into existing microscopes. Such schemes are useful for generating spatial light distribution effect, for example, interference effects.
The invention is illustrated by the following drawings.
Fig.1. The General scheme of the device.
1 - the source of optical radiation (laser); 2 - optical beam; 3 - medium (liquid); 4 - the object (particle); 5 - mirror; 6 - the main optical system; 7 - secondary optical system; 8 - movable table; 9 - glass cover; 10 - area of heat dissipation; 11 - acoustic waves; 12 - unit mechanical position control of the movable table; a 13 - block spatial displacement of the optical beam.
Fig.2. Schemes with different spatial geometry of the light beam cross-section about byobject.
1 - light beam; 2 -; 3 - acoustic waves.
And one beam with Krugloye beams around an object; D - ring shape of the light beam; E is the partial overlap of the light beam on the object; W is a combination of two or more light strips; 3-the combination of light arcs (or sickles).
Fig.3. Schema manipulation of objects (particles) using photoacoustic lenses.
And optical image curved lenses: 1 - optical beam; 2 - focused ULTRASONIC vibrations; 3 - object.
B - photoacoustic lens generating ULTRASONIC oscillations on the input surface: 1 - radiation; 2 - absorbing coating; 3 - the acoustic lens of the optical material; 4 - acoustic oscillations; 4 - object.
In photoacoustic lens with the generation of ULTRASONIC vibrations on the surface of the microlenses: 1 - optical beam; 2 - the acoustic lens; 3 - absorbing coating; 4 - focused ULTRASONIC vibrations; 5 - object.
Mr. photoacoustic lens on the surface of the absorbing liquid: 1 - radiation; 2 - liquid; 3 - region absorption; 4 - focused ULTRASONIC vibrations; 5 -; 6 - dotted line shows the approximate intensity distribution in the cross section of the laser beam, 7 - optic plate.
D - line photoacoustic lenses: 1 - laser beams; 2 - line photoacoustic lenses; 3 - focused phased array ULTRASONIC vibrations; 4 - object.
increase; 2 - fiber; 3 - region absorption in liquids; 4 - acoustic waves; 5 - object.
B - scheme with an absorbing coating on the end face of the fiber: 1 - light, 2 - fiber; 3 - absorbing coating; 4 - acoustic waves; 5 - object.
In the diagram with an additional tip of: 1 - light, 2 - fiber; 3 - tip; 4 - absorbing end wall, 5 - acoustic waves; 6 - object.
Mr. optical fiber photoacoustic lens on the end: 1 - fiber; 2 - surface concave shape on the end face of the fiber with an absorbing coating; 3 - Akusticheskie waves; 4 - object.
D - optical fiber photoacoustic nozzle: 1 - fiber; 2 - akusticheskaya lens; 3 - the absorbing foil; 4 - acoustic oscillations; 5 - object.
Fig.5. Scheme photocasting separation of the particles from the substrate.
1 - radiation; 2 - optical substrate, 3 - medium (liquid); 4 -; 5 - region absorption (dissipation).
Fig.6. Diagram of light traps (cage) with two cylindrical beams (shown their axial section).
1 - the first laser beam cylindrical geometry; 2 - the second laser beam; 3 -; 4 - pressure force.
Fig.7. Schemes with one cylindrical beam (photoacoustic tunnel).
And the use of vertical convectio
B - the use of thermal axial acceleration with the Central beam: 1 - optical beam cylindrical geometry; 2 -; 3 - acoustic oscillations; 4 - radiation in the Central part of the beam.
Fig.8. Controlling movement of the object in the pipe: 1 - pipe optically transparent cylindrical walls; 2 - optical beam flat geometry (shown in section); 3 -; 4 - acoustic oscillations; 5 - alternative (axial) option laser exposure.
Fig.9. The additional flow of the absorbing gas or liquid: 1 - optical beam; 2 -; 3 - acoustic waves; 4 - additional modules from absorbing radiation components; 5 - streams with absorbing components.
Is depicted in Fig.1, the device operates as follows. The optical source 1, preferably a laser that generates an optical beam 2 is directed into the medium 3, which is subject to manipulation of the object 4. An example of the environment of the object may be a gas, including air, condensed medium in the form of a liquid, solution, gel, tissues, individual cells, solid surface, etc., For possible changes in the direction of the beam, which is necessary, for example, in schemes inverted microe of the object is formed with the main 6 and more 7 optical systems. In the case of using elements of the microscope the object is placed on a movable table 8 between two cover glass 9. As a result of optical absorption of radiation in the environment part of the absorbed energy due nonradiative transitions is converted into heat energy environment, causing it to heat. Rapid thermal expansion of the heated local volume of 10 leads to the formation of acoustic waves 11, extending in the direction of the object 4. Further, by virtue of direct or indirect action of this wave on the object 4 are the forces acting on this object and vibrate. We can distinguish the following main reasons for the formation of such forces on the example of a liquid medium: acoustic radiation force pressure, the formation of the so-called acoustic flows, the effect of added mass, etc., . It should also be noted that with periodic exposure to high acoustic frequency, the particles start to oscillate with the frequency of acoustic oscillations. The necessary movement of the object 4 in the environment 3 (e.g., liquid) may be achieved by moving the table 8, driven by the scanning unit 12 in a fixed position optical system, or what omashu unit 13. As specific examples of possible schemes scanning can note the oscillation of the lens, the movement of the mirrors, the periodic displacement of the fiber tip or use of the acousto-optic modulator. It is also possible combined movement using simultaneously two ways. You can also enter a joystick for manual manipulation of an object in the environment.
In Fig.2 shows different ways (but they do not exhaust all possible schemes) distribution of the radiation intensity in the cross section of the laser beam in the object plane. The simplest scheme is But one beam 1 round shape in cross section, located next to the object 2. With this geometry are formed diverging acoustic vibrations 3 that allows you to move the object in only one transverse direction with relatively low accuracy. However, this is quite simply implemented in practice, the scheme is suitable for rough handling object in a given direction based on the use of standard microscopes, in which only added optical console with an additional laser. Since in this scheme there is no adjustment movement in the longitudinal (along the axis of the protected area is two-dimensional manipulation in the space between the two spaced planes. An example of the latter can serve as the space between the two cover glasses, microscope. When focusing radiation in the line 1 (scheme B), that is implemented in the simplest case, using a cylindrical lens on the object 2 acts already flat acoustic wave, which slightly increases the accuracy of its targeted spatial displacement in a given direction. In addition, the plane wave can provide exposure to a large volume environment that allows you to control the movement of multiple objects. This scheme is also useful for the separation of the array of particles into separate parts. With such a geometry axis is formed as if the piston action of the pressure from the area of heat dissipation. Thus, the advantage of this scheme is the relative simplicity of the technical implementation, for example, using marked cylindrical optics and ease of control of the displacement of a particle in one direction, but the accuracy of the determination of the exact trajectory, however, is low. It should be noted the possibility in this scheme of using only two adjacent separate beams (scheme A, but with two beams) that can easily be implemented in practice by performing additional A transparent plate such system allows to form any desired number of light beams, oriented in line. The change of angle with respect to the optical axis can also change the distance between the two beams. However, greater precision has a diagram depicting the optical beam 1 in the form of a segment of an arc. The object 2 will be converging acoustic wave 3. The accuracy will increase with increasing size of the arc, i.e. the scope of the object light beam. This geometry can be realized by using an optical system with a deliberate aberrations that distort the optical beam in the desired direction, in particular forming a Crescent-shaped spots, as shown in the drawing. The advantage of this geometry, as in the case of pure arc, is the ability of a small focus of the acoustic waves on the particle due to the effect of an acoustic lens. This geometry can also be formed by using, as described above, several discrete optical beams of circular form, one of which is shown in the diagram (Fig.2). This can be achieved in various ways, for example using the system of dividing mirrors, multiple optical fibers, multiple lasers, etc. To keep the object in sudanplane individual point sources 1, the minimum amount which must be 3 or better 4. The object 2 is located at the geometric center of these sources. In this case, from each source applies a spherical acoustic wave, while the impact of these waves, the object 2 is in the area of minimum pressure, i.e. with equal acoustic pressure approximately in the center. As each source will push the object away from you (at a certain ratio of acoustic properties, as noted above), the stabilization of the position of the object will be dynamic in nature and the object may experience a small spatial fluctuations, i.e. to "tremble" or "dance". Sources preferably be positioned evenly around the particle, but it is not really critical, as a possible irregularity will only lead to a small asymmetric displacement of the particle with respect to the light spots. In addition, it is also possible due to the asymmetry the asymmetry of power of the acoustic pressure of the individual zones. If the optical system, such a small imbalance can be compensated for by changes in the power of the individual beams.
The optimal solution is fo from all sides, that provides a stable position of the object in the center or purposeful movement in a given direction. Most simply implement this scheme with the laser beam in the center of which is created in one way or another failure intensity, for example, due to aberrations, the use of spatial filters, diaphragms, including opaque Central part, the diffractive effects, etc. of the Light ring can also be formed by rapidly scanning the laser beam in a circle, for example, using a scanning optical system based on a rotating mirror. It is also possible to use a scanning laser beam in a spiral with the help of Senatorov used for laser skin treatment. In this case, the possible capture of the object in a sufficiently large area with its subsequent transportation to the center of the spiral specified.
It should be noted that in such schemes there is also the pressure force, which is directed into outer space. They can play both a positive and a negative role. In particular, during transport of the object they like to push on your way other unwanted objects. On the other hand, they can prepatch time of the laser at the point of convergence of these objects. When capturing another object then they may be held together using this schema.
The development of the proposed devices should also be taken into account that the same acoustic wave can exert the opposite effect on particles with different acoustic properties (see above): "light" in acoustic terms (see above) particles it can attract and heavy to push. This can be based sorting of particles with different properties. In the future, if not specified explicitly, it will be assumed a case of acoustic repulsion of particles.
The size of the field of spatial fixation can be adjusted by changing the diameter of the light ring. It should also be noted that, in principle, valid in some cases, the touch of the radiation of the object, if this does not occur the problem of radiation damage. For example, this is true for optically transparent object or the relative low intensity of radiation, in particular, when the object touches significantly weakened by the intensity of the wing of the laser beam with Gaussian intensity distribution in the cross section. On the other hand, when such geometry (scheme F) by the absorption of radiation 1 in part on the to be thermal expansion of a small area on the border of the particles, that will create a kind of reactive power movement in the direction opposite to the extension. For the case of light objects it can be a secondary operating pressure due to the emission of the heated zone of infrared radiation. These schemes are non-destructive sample impact favourably differ from the already known (see above), because they do not use reactive return leaves the object product laser allazei or plasma, which destroy the sample. In addition, they allow very smooth to adjust the position of the object, while the analogues creates a fairly large initial acceleration, and the direction of this acceleration is quite difficult to regulate. As already noted, the creation of the necessary configuration of the laser beam can be achieved through the use of separate beams, and in this direction may be useful scheme that uses multiple linear elements (scheme W), located, for example, the tangent of the desired virtualnogo rings, or multiple arcs of a circle, or sickles (scheme 3). In these cases, you can use to split one beam into several other or even use to create a separate lasers, such as compact and inexpensive semiconductor by laser radiation of acoustic lenses of different configurations, for example, due to the formation of their corresponding optical images in the environment. In addition, the combined lenses, which can be called photoacoustic (PA), in contrast to the traditional scheme of generation of the ULTRASONIC vibrations using piezoelectric elements, coupled to the lens) the source of these oscillations is a thin layer of absorbing radiation of the coating or film is irradiated with laser radiation. This coating is desirable to choose a high coefficient of thermal expansion. The mechanism of generation of ULTRASONIC waves based on the fast periodic thermal expansion of these elements. There are several variants of such schemes (Fig.3). In the first of them And the profile of the acoustic lens is formed by voluminous curved configuration of the laser beam in an absorbing medium, due to the FA effect in the environment generates acoustic vibrations 2 (Fig. And shows their front propagating to the object 3 along the normal to the surface of the image such FA lenses. The advantage of this scheme is the remote nature of the formation of the acoustic lens almost any configuration. The most easy to implement cylindrical FA lens, although there are no fundamental restrictions on the creation and trehmernom, simply a combination of two or three cylindrical FA lenses. In scheme B is used for the traditional design of the acoustic lens, in which ULTRASONIC vibrations are generated by absorption of laser radiation 1 in absorbing coating 2 is deposited on the outer surface of the acoustic lens 3. These ULTRASONIC vibrations 4 apply to the surface with high curvature, which is the concentration of focused ULTRASONIC vibrations 4 on the object 5. The advantage of this scheme is the relative ease of varying the required parameters of the ULTRASONIC wave due to the change of the laser radiation parameters, such as frequency and phase of the acoustic waves. Honors the following schema is the use of laser radiation 1 for generating ULTRASONIC oscillations at the output of the acoustic system 2 using the antireflection coating 3 is deposited on the curved surface of the acoustic lens. In the case of relatively strong absorption of radiation in the environment generating ULTRASONIC oscillations are possible due to the absorption of radiation in a thin layer of fluid immediately in contact with the curved surface of the acoustic lens. In particular, in the case of the aquatic environment for this podhodyaschego lenses due to the absorption of radiation 1 in the liquid 2 directly on its surface 3. Forming a converging acoustic waves 4 acting on the object 5, is achieved by a corresponding change of the beam intensity profile 6 in the cross section of the beam, providing increased oscillation amplitude in the direction of the focus area. In addition, you can use the principles of phase gratings, for example, through the use of additional plates 7 with appropriate filters, or a specific configuration of the absorbing film on its surface. This plate 7 is placed on the surface of the liquid, provides additional amplification of the amplitude of acoustic waves due to the introduction of rigid boundary conditions during the formation of acoustic waves. It should be noted that the role of such plates can be transparent walls of the chamber in which the object resides, and in this case the vertical geometry of the FA lenses. In scheme D, the concentration of acoustic oscillations in the focus area is achieved due to phase matching of acoustic waves from a separate FA lenses, assembled in a line. These waves are formed using separate laser beams 1 in the line of absorbing targets 2, acting as a phased antenna ensures compliance which may be formed with continuous lasers, the power modulation in which the required frequency range (1-100 MHz) is achieved using electro-optic and acousto-optic modulators. You can also use pulsed lasers with high frequency fill packs of individual pulses. In the described schemes being implemented the idea of using focused ULTRASONIC waves, the source of which is the quick dissipation of the absorbed laser energy. Among the potential implementation of such schemes should be noted focusing of laser radiation in one of the foci of the elliptical acoustic mirror, which pereformuliruem emerging acoustic oscillations in the region of the second focus, which can be located in hard-to-reach optical radiation area, for example within a living organism. This can be used to generate acoustic waves the phenomenon of optical breakdown . This way you can focus acoustic waves to a greater depth in the skin and various internal organs with the use of the water environment on the surface of the body for the desired acoustic matching. One of the potential applications is to accelerate the selective delivery of drugs to the desired area, for example, the proposed invention it is also possible to use more simple circuits using optical fibers (Fig.4), having, however, of great practical importance. In all these schemes, in particular, the delivery of the laser radiation 1 is carried out using optical fibers 2 that are placed in the appropriate environment. The resulting acoustic oscillations at the end of the fiber 4 are then on the object 5. The mechanism of generation of acoustic waves can be different. For example, it may be absorption in the environment near the end of the fiber, which leads to release of thermal energy and the subsequent formation of the acoustic oscillations. At the end of the fiber 2 (scheme B) may be caused absorbing coating 3, the absorption which leads to the formation of acoustic oscillations 4. The difference scheme is a fixation on the fiber tip 2 tip 3 with an absorbing element 4 at its end. As such element can be used various absorbing film. It is also possible placement in the space between the end face of the fiber and flexible pleney absorbing fluid, sharp thermal expansion due to the absorption of radiation will lead to a sharp move of the specified film and ultimately to the generation of acoustic oscillations 5 acting on the object 6. In scheme G shows that by changing the curvature of the end VALSA can also be docked to the end of the fiber 1 (scheme D) as a separate nozzle 2. The principle of this acoustic nozzles, as the previous scheme that was outlined in the description of the circuits of Fig.3. Such schemes are a close analogue circuit And Fig.2. but with the use of fiber-forming light beam near the object. It should however be noted that due to the absorption of radiation in these coatings in optical fiber systems eliminated the problem of radiation damage to the object, so that the fiber can be brought to the object in any direction. It is interesting to note the potential for the creation of optical breakdown at the end of the fiber in a transparent fluid, which in addition to increasing the amplitude of the acoustic waves allows to avoid direct exposure to radiation on an object due to its almost complete absorption in optical breakdown (original optical effect of the "black hole"). The immediate location of the fiber in the environment has its advantages also in the management of relatively large objects. For example, such a scheme with the use of the endoscope can be used to move the stones in the bladder in the desired direction or fixing in the desired position, particularly when intracorporeal or extraorally lithotripsy. Atlususa proximity effect by acoustic vibrations. In addition, it is possible to combine these microneedles and fiber delivery of radiation by placing the fibers in the hollow Mitroglou. The result is that you can control the object in two modes: contact and contactless. By analogy with the use of many laser beams to create the desired spatial geometry (Fig.2) a similar approach can be implemented using optical fibers. As example can be mentioned the use of two fibers arranged against each other, rulers fibers or their placement around the object so that the distal ends of the fibers form a discrete ring, or even a ball in the center of which was the object.
In parallel with the fiber close to it you can also place a hollow microtubules, through which a slow suction of liquid or gas from the volume manipulation. Thus you can create the effect of a vacuum cleaner, attracting the particles to the suction hole with mesh filter on the end and fixing them, thus, the position near the end of the fiber. By adjusting the magnitude of suction and photoacoustic repulsion of particles, you can get the location of the particles at a certain distance from the end Volodya to the layout area of the egg, when researching the different interaction between cells and drugs, and the formation of spatially selective chemical and photochemical reactions. Adjusting for these effects is stuck and otlipaniya you can ensure separation of particles from the walls and precision cleaning of the walls.
One of the problems in the microscopic study of microbioreactors is sometimes the difficulty of their substrate from the substrate on which they are placed or stuck due to different adhesion forces (van-der-Waltz, electrostatic, electrochemical, etc). To solve this problem, i.e. separation are stuck object from the substrate, you can use a very simple private scheme shown in Fig.5. The laser light 1 goes from transparent to this radiation substrate 2 in medium 3, where the object 4. In order to avoid damage to the object, the radiation wavelength is selected in the range of strong absorption environment. For example, in the case of the aquatic environment that may be erbium laser with approximately the wavelength 2,89 μm almost completely absorbed in the water layer 5 of a thickness of a few microns. Resulting piston force acoustic pressure easily separates the particle from poverkhnostnaya scheme irradiation, to avoid the direct effect of radiation on the object. Another solution may lie in the location of additional opaque film on the surface of the plate 2, if permitted by the research task. In this case, the absorption of radiation in the liquid or in the film she will come into motion and will act on the object, that will completely eliminate the chance of getting even a small part of the radiation on the object.
As already mentioned, the presented scheme allows to manipulate the position of a particle mainly in one-dimensional and two-dimensional volumes. For example, the ring geometry is only one of the light beam will move the particle without additional measures only in the transverse direction when the movement of the beam perpendicular to its axis. It is convenient for the case of two-dimensional volumes generated, for example, two spaced planes, as in the case of cover glass for microscopy. Movement in three dimensions provides the scheme with two cylindrical beams 1 and 2, arranged at an angle to each other (Fig.6). Object 3 is formed inside thus volume, and is influenced by the pressure force from all sides this amount. Felicelli tens of degrees is formed slightly longer in the space volume. The convenience of this scheme is the placement of two beams or two separate sources close to each other. When mutually perpendicular orientation of the beams is formed by the minimum possible amount of original light traps. However, there is a need for substantial spatial separation of the two beams. These patterns resemble the case of multiple projectors directed at different angles in one area. The only difference is cylindrical laser beams. Thus, it is possible to manipulate the position of the light objects in the air, for example, geodesic balls or promotional materials. At the angle of 180° beams are oriented towards each other. Their small focus and offset of the optical axes and foci relative to each other provides additional opportunities for the formation of suitable geometry required for the manipulation of objects. The motion of the object is provided by synchronized movement of the two beams. The minimum required number of bundles or two, but to enhance the operating forces may increase their number.
Possible in principle a number of special cases that allow certain m is received in Fig.7-9. In Fig.7A presents a scheme for the implementation of the vertical motion of the particle along the axis of the cylindrical beam 1, which is located inside the object 2. Holding the object within such a beam is due to the strength of the acoustic pressure 3, formed as a result of absorption of the radiation environment only in the area of the original optical walls. Thus, a "photoacoustic (PA) tunnel, just inside of which can move the particle. Movement vertically may be provided by gravitational forces. Since the absorption of radiation in the region of the walls of the FA tunnel is warm, it can lead to the formation of convective flow medium 4, and move upward and engage the object 2 in motion.
In diagram B the motion of the object 2 up is ensured due to the presence in the Central part of the cylindrical beam 4 impinging on the object. The motion of the object will provide periodic thermal expansion of the irradiated part of the surface of the object, as described previously. In this case, direct absorption into the object of laser radiation in the Central part can lead to the creation of thrust, providing longitudinal movement of the object. The need for what can be thrown out of the beam due to the dominance of acoustic forces in the Central part.
Movement in the transverse direction can be achieved by moving the beam in the transverse direction one way or another, for example in the angular rotation of the beam. In Fig.8 presents another private schema manipulation of object 3 at its location in the transparent tube 1, which is perpendicular skipped a laser flat geometry 2. In this case, is formed of a flat acoustic wave 4 acting on the object 3. By analogy with previous schemes you can use two flat beams located on opposite sides of the object or the use of cylindrical geometry of the optical beam within which the object resides. You can also use the axial geometry of the laser beam 5 (shown by the dotted line), the absorption of which is carried out or absorbing medium, such as air, or in the object itself.
For this purpose, the object may be coated with a special absorbing coating with a high coefficient of thermal expansion. Another solution already described above, is the location of the absorbing film on which an object is placed. Power piston character will be formed in the film, and in front of this clause is already will act on the object (model laser cap). In this case, there is no requirement for optical transparency of the specified tube. Particularly promising application of such schemes for the transport of biological objects such tubes. In particular, the analogue of  is only a process of partial ejection of particles in the corresponding tube, but not solved the question of the future management of these particles inside the tube. Therefore, the present invention can usefully complement the capabilities of existing commercial systems, and the combination of the two systems will not be a problem, because you can use the same laser that is used in the specified similar to.
A fundamental condition in the present invention is the presence of the absorbing medium, in which the object resides. No matter the type of this environment, such as a gas, in particular air or liquid. The difference will manifest itself only in the manifestation of the physical mechanism of generation of the acoustic gradient and the magnitude of the pressure forces acting on the object. The increased pressure gradients can be achieved by increasing the energy of laser radiation, and by increasing the absorption in the medium, for example, by adding various pagelog is object 2. Strengthening acting on his acoustic forces 3 is achieved by adding one of several modules 4, capable of forming a flow of the absorbing medium 5 (gas or liquid) is directed to the field of manipulation of the object. These additional threads may also be of different geometry: cylindrical, flat, etc. and can be directed at different angles to the axis of the laser beam, including the distribution along the axis or perpendicular to it, as shown in Fig.9.
Examples of practical implementation
1. Photoacoustic Curling irons with pulse laser to manipulate the position of biological objects (cells, molecules, viruses, and so on). This device is based on a standard schema invert microscope, in which the additional optical module is used console from affecting the laser. According to invert the schema of the specified microscope effect on the objects is carried out by supplying laser radiation to the subject table below. As the environment uses the standard physiological aqueous solutions. As a radiation source is used, a pulsed nitrogen laser with the following parameters: energy range 10-6-10-3J,p>Because of the relatively strong absorption in the water this laser makes it possible to create a sufficiently high values of pressures in the range of tens and hundreds of bar, which is sufficient to move objects of sizes up to several tens or even hundreds of microns. As shown by numerous studies (see for example ), the magnitude of such pressure has almost no effect on the biological structure due to the proximity of the acoustic properties of the environment and cells containing large amounts of water. It should be noted that such a system can be quite simply implemented on the basis of existing commercial systems designed using the similar characteristics of the laser for optical cutting of biological objects and their final separation method ejection .
2. Photoacoustic tongs with a continuous laser to manipulate the position of biological objects (cells, molecules, viruses, and so on). The difference of this circuit from the previous one is the use as sources of laser radiation in the middle infrared range, where the absorption of most biological objects is minimal.
This is an additional factor reducing the likelihood of the damage of the grain with a wavelength in the spectral range of 750-900 nm or neodymium laser with a wavelength of 1.06 µm with the power of both lasers in the range of 10-200 mW. The required modulation is carried out using electro-optical modulator in the frequency range up to 100 kHz. Such a system similar to the diagram commercial vehicle "laser forceps" , the principle of operation is based on the creation of optical gradient forces due to the effect of light pressure. The difference will be added to this system, only the specified modulator, as in the similar using the laser in a continuous mode. The objects and the environment are the same as in the first example of practical implementation. Amplification of acoustic pressure is achieved by maintaining in the solution of various absorbing additives. For example, in the case of using a semiconductor laser as such additives can be used indocyanine green in the concentration range of 0.01 to 0.2%, with a maximum absorption band in the region of 800 nm. In both devices the easiest scheme is implemented with a single laser beam with a circular cross geometry (Fig.2A) or in the form of a luminous line (Fig.2B) by adding a cylindrical lens to the main optical system. The formation of multiple optical beams is achieved by using well-known circuits using the system of dividing mirrors or diffraction schemes described the m device in saline solution is placed the end of the optical fiber, made of quartz with a polymer coating and a diameter in the range from 60 to 800 μm.
Observation of the spatial position of the fiber tip in the solution can be carried out using standard microscopes, including those listed above. For spatial manipulation of objects fiber can be firmly fixed by means of an additional holder, and the necessary spatial movement is provided a movable table on which the object resides. As the radiation source used pulsed neodymium laser with the following parameters: wavelength of 1.06 μm, the energy range 10-7-10-4J, the range of pulse durations of 10-710-9sec. To increase the absorption solution is added to the fine powder made from medical coal.
4. Photoacoustic device for manipulation of objects using standard acoustic lens. At the heart of this device is the principle of acoustic forceps, in which the capture of particles in the focus area standard acoustic lens. However, to create high-frequency acoustic oscillations is used photoacoustic effect in absorbing coating on Wlodawa film of zinc oxide, used in the normal mode for receipt and generation of acoustic oscillations. This film is irradiated by the pulsed radiation of a neodymium laser with the following parameters (see description in ): wavelength of 1.06 μm, the duration of a single pulse of 200 PS, the distance between the individual pulses of 5 NS (i.e. the fundamental frequency of approximately 200 MHz), the width of one pulse of 200 NS, and the frequency of repetition of 2.7 kHz. The radius of the acoustic lens 200 μm. Laser generation of ULTRASONIC waves, in addition to the main optical frequencies, the formation of higher harmonics, in particular the fourth, with a frequency of about 800 MHz. Selection of the vibrations can be realized by choosing the dimensions of the acoustic lens. At the specified radius, this lens provides the focusing of the acoustic waves initiated by the described laser in the aquatic environment in the spot about the size of 2 μm. In order to avoid radiation destruction of the antireflection coating radiated power must not exceed 2 kW. However, this is not critical, since it does not impact on the object itself. Therefore, the generation of acoustic oscillations are possible due to the formation of plasma on the surface of the absorbing target. This system allows you to create akusticheskiy the image formation of the acoustic lens in the water. As previously noted, in principle, possible optical forming a three-dimensional image of a cylindrical acoustic lens directly in water, for example, for the purposeful use of aberration or holographic effects. If this is not the fundamental technical limitations due to the electro-optical modulation of the laser radiation, the formation of acoustic waves with a frequency of 3.5 MHz (as in the acoustic Siptah ), which is sufficient for the capture and manipulation of polystyrene beads with a size up to 0.2 mm . Thus for the sustainability of capture it is possible to use a counter geometry of the two laser beams and the corresponding FA lenses. Another solution is the use of two cylindrical beams with mutually perpendicular orientation relative to each other.
6. Photoacoustic tunnel. As the source of radiation is relatively high-power pulsed carbon dioxide laser, which is widely used for processing various materials. Its parameters are: wavelength of 10.6 μm, the pulse repetition frequency up to 100 Hz, the average power of 2 kW. Such laser-formed cylindrical geometry of the laser beam with an external diameter of 10 cm and the shielding only the Central part of the beam. Such geometry can be also achieved by changing parameters of the resonator, while the external control is more preferable. Due to the absorption of the radiation of this laser in the air molecules carbon dioxide and water vapor are generated significant acoustic vibrations that can be heard by the naked ear. This system allows you to capture and hold inside the laser beam relatively light items like a small balloon or light plastic products. However, this can be used in problems of geodesy or theatrical or promotional purposes. Movement along such a photoacoustic tunnel with a vertical arrangement of the laser beam may be caused by purely thermal convection. It is also possible periodic overlap of the Central part of the beam through, for example, fluctuations in the specified aperture. This movement will be ensured by periodic thermal expansion of the irradiated portion of the object. If partial radiation damage of the object is not scary, the movement of an object up possibly due to the described early reactive power generated in the power of the recoil effect evaporation, laser ablation products, which may be coated with a special reflective coating or placed inside a protective capsule. To enhance absorption, it is possible to use the add in a basic environment different absorbing additives. For example, in the case of the described laser into the air, you can inject gas SF6possessing a very strong absorption at the laser wavelength on carbon dioxide.
A lesser effect, but also very tangible can be achieved by injection of water vapor into the laser beam, for example, due to thermal evaporation of water, and for this you can use the radiation of the same laser. This system is very promising for the manipulation of various aggressive chemical compounds, when working with chemical reactors, etc., or in medicine to move sterilized drugs in the absence of mechanical contact with them.
Calculations show that when using existing in the industry of gas dynamics in carbon dioxide lasers with power levels up to several hundred kW is possible to transport relatively light objects weighing tens and possibly hundreds of grams at a distance of at least several hundred meters. Thus, with the invention is possible for the first time photoacoustic levitate various objects in the observation that the mechanism of this levitation is not obvious, that you can use in theatrical and circus performances.
7. Optical manipulation of objects on the surface of a solid phone as objects can be elements of microelectronics and optics, which are contactless, i.e. in the absence of possible contamination, move across the surface of the corresponding substrate. As the radiation source, it is advisable to use a laser with minimal absorption in the substrate in order to avoid possible optical damage. For example, in the case of a substrate of semiconductor materials, in particular Germany, it is advisable to use a neodymium laser with parameters similar to those described in example 2. To move the micro-objects in the desired direction along the surface of the substrate is most suitable distribution of light energy in the form of a luminous stripe size 20 to 3 microns.
Other examples can be mentioned the hypothetical possibility of flow control medications or special samples (liposomes, antibodies, planted on microspheres, gold microparticles, fluorescent or photothermal probes, etc.,) within the cells of various tissues, blood and lifesouth due to optical formation temperature and the heat is th area, including against the forces of hydrostatic pressure in blood vessels, interstitial fluid, in eye space or inside some cancer formations.
If the object is small enough, then he, as you know, is experiencing chaotic Brownian motion. Formed using a laser thermal local sources near object can create the effect of "directional Brownian motion". It is interesting to note that the chaotic spatial fluctuations of laser radiation around an object, formed, for example, speckle-inferometry allow as significantly enhance Brownian motion, so it seems to weaken what happens when you subtract the phases flythrough optical radiation and natural thermal fluctuations of the environment.
The object may influence thermal motion of particles and associated chaotic acoustic vibrations generated due to the effect of acoustic emission heated phone This effect manifests itself in the absence of modulation of the heat source, and the range of acoustic frequencies is quite wide, up to units and tens MHz.
In addition to the directed thermodiffusion the invention allows the implementation of solar thermal sources. For example, their orientation in the form of a ring in microscopic studies in two-dimensional space between the cover glass allows you to concentrate particles in the centre of this ring. Even focusing radiation near the particles allows due to convection from the zone of irradiation to ensure the movement of particles away from the area.
Similar schemes in addition to the manipulation position of the individual particles allow sorting in the zone due to different particle mass and acoustic properties.
In the present invention on the particle acts acoustic wave, which, as already noted, does not exert almost no influence on the properties of the object, at least this potential impact is much smaller than in the case of direct exposure to the laser radiation, as in the prototype. By the close location of the light beam to the object may be a manifestation of heat exposure on the object due to the diffusion of heat from the heated radiation zone. However, the short duration of the laser pulse is less than 10-6sec or high modulation frequencies more than tens of kHz, the diffusion length is small enough (units and tens of microns) to have a significant impact on the object. implement the previously described schemes aimed thermal diffusion or convection. Very useful for facilities management and security purposes in many cases, using invisible radiation, the introduction of additional pilot laser radiation which is combined with the light beam from the primary laser. As such the pilot lasers are most suitable semiconductor lasers or LEDs with emission in the red spectral range.
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1. Device for the optical manipulation of the spatial position of objects in the environment that includes a source of optical radiation, an optical system, the spatial movement of an object in the environment associated with the optical system and/or with a mobile table, additional optical unit located after the basis of the fact, the radiation source is made continuous and entered the modulator of the radiation intensity associated with this source, or the source of radiation is made of pulse, an additional block is made so that a desired distribution of radiation in the environment surrounding the object and includes a lens or system of lenses, or aperture or spatial filter, or holographic elements or diffractive elements, or interference elements or optical elements for spatial scanning of a light beam around the object, or one or more flexible optical fibers, and the wavelength of the optical source and the optical parameters and the composition of the medium chosen to ensure the absorption of radiation in the environment, time and energy parameters of the optical source is selected on the basis of the conditions for thermal or thermal and acoustic gradients in the environment around the facility, sufficient to spatial fixation in a given volume or movement in a given direction.
2. The device under item 1, characterized in that the parameters of the secondary optical unit is chosen in such a way as to ensure that the environment surrounding the object Respray circumference, or polycarpa, or in the form of a light ring around the object, or in the form of a continuous light spot with the intensity of the radiation, decreasing towards the center, or in the form of a light ring around the object, or in the form of a light ring in the center of which there is a separate light spot, and the distribution of power can be both continuous and discrete, that is, consisting of separate light spots, or stripes, or polycarpou, or arcs of a circle.
3. The device under item 1 or 2, characterized in that the optical unit is made in the form of a cylindrical lens, or oval lenses, or one or more optical plates with adjustable angle of inclination relative to the optical axis of the main optical system.
4. The device under item 1, characterized in that between the secondary optical unit and the object introduced an additional optical elements placed in the environment near the object and represents an optically transparent to the radiation plate, or a plate with an absorbing coating on the surface facing to the object, or a plate with an additional absorbing film on a given surface, or only one absorbing film, so that the plane indicated elemento next to the object placed acoustic lens, oriented in space so that the radiation falls on the entrance surface of the lens, the focal point of the lens coincides with the position of the object, and on the input or the output of the lens surface caused absorbing coating, and in addition provides unit changes the frequency of the optical effects associated with the optical source, or block mechanical movement of the lens associated with this lens.
6. The device under item 5, characterized in that separate the acoustic lens incorporated in the line, the optical system is so designed as to ensure the formation of multiple light beams, each of which falls on the corresponding lens, and put the block of phase delay, coupled with each of the lenses and the radiation source to provide the group of lenses in the mode of the phase of the acoustic antenna.
7. The device under item 1, characterized in that the input of the second additional optical unit associated with the first block and an optical system made in the form of a beamsplitter plates or diffractive elements or optical fibers, oriented in space so as to provide separation of the primary light beam on the several other, at least two light beams, which may be oriented perpendicular to each other or towards each other, moreover, in the latter case, the beams can be aligned, and the optical axis can be parallel displaced relative to each other, and the position of the tricks can be the same, lying in the same plane or to be displaced along the optical axis relative to each other.
8. The device under item 1 or 7, characterized in that the parameters of the additional optical unit together with the parameters of the optical system is chosen in such a way as to ensure the environment around the object three-dimensional distribution of energy in the form of a single cylinder, or a concave lens, or a sphere object inside of this sphere, or two intersecting cylindrical beam with the object within the area of their intersection, or periodic spatial gratings with different step from a few microns to several millimeters, or their various combinations.
9. Device according to any one of paragraphs.1-8, characterized in that to generate the required volume of the spatial distribution of radiation near object introduced additional sources of optical radiation with independent main optical systems and optical blocks.
10. Device according to any one of paragraphs.1-3, characterized in that additionally introduced the subject provides specified distribution of light energy within the tube when the orientation axis of the optical beam along or perpendicular to the specified axis of the tube, including a flat geometry of a single light beam, the plane of which is oriented perpendicular to the specified axis of the tube, or two flat beams, between which the object resides, or cylindrical geometry of the optical beam.
11. The device under item 1, characterized in that the modulator is connected to the secondary optical unit, this unit is designed to provide the cylindrical geometry of the light beam with a cross section in the form of a ring and an independent Central part, the modulator is designed to provide intensity modulation of the Central part of the light beam, independent of the modulation of the peripheral annular part.
12. The device under item 1, characterized in that an additional optical unit made in the form of optical fibers, which are fixed in space with additional holder so that the fiber tip was placed near the object, and the holder provides additional device for moving the holder along with the fiber in any given direction.
13. The device according to p. 12, characterized in that the end face of the fiber caused absorbing coating and/or recorded absorbent from the hay absorbing radiation coating, or to the end of the fiber attaches acoustic lens with an absorbing coating on the flat input surface or the output of the concave surface.
14. The device under item 1, characterized in that the introduced microscopic cover glass placed on a movable table, between which the medium with the sample, as the optical system is inverted microscope, and for precision control of a mobile table system introduced for the type of joystick.
15. Device according to any one of paragraphs.1-14, characterized in that the optical system provides light energy distribution around the object, which is partly in contact with the object in one or several areas of the border, including touch around the perimeter of the object.
16. Device according to any one of paragraphs.1-15, characterized in that the quality of the environment using different absorbing the radiation fluid, or liquid solutions, or gases, or a mixture of gases, including air, or gels, or biological environment.
17. The device according to p. 16, characterized in that the optical system provides for a specified distribution of radiation within the environment type of living biological tissues or individual cells, and as the object of the bearers of the type of polystyrene microspheres with attached biological elements, or different fluorescent probes, or thermal behaviour of the sample in the form of chemical compounds, various metal and non-metallic beads.
18. The device under item 1, characterized in that the absorption in the medium is provided by ensuring that the composition of the medium, which comprises absorbing the radiation components of different nature.
19. Device according to any one of paragraphs.1-18, characterized in that the entered one or more additional blocks feed streams absorbing additives in the area of irradiation, which provides both discrete and continuous supply of these flows, including the use of the aerosol stream, the specified block or blocks have a different orientation with respect to the optical beam, providing including coaxial and perpendicular to the direction of the flow relative to the optical axis of the beam and different spatial geometry of these flows from cylindrical to flat.
20. The device under item 1, characterized in that the optical system provides for a specified distribution of radiation in the environment in contact with the surface of solid substrates of different nature, including semiconductor or optical elements, and objects are placed on powerhe uses a laser, operating in the continuous mode, and introduces additional modulator, docked with the laser to provide modulation of power in a wide range of frequencies from a few Hz to hundreds of MHz.
22. Device according to any one of paragraphs.1-20, characterized in that the radiation source is a source of pulsed radiation with a pulse duration lying in the range 10-3-10-15with, and introduces an additional block which is connected with the source and provides a mode of repetition of individual pulses in the range from a few Hz to hundreds of MHz.
23. Device according to any one of paragraphs.1-20, characterized in that the light sources can be used in many known gas, solid state, semiconductor lasers and dye lasers operating in continuous or pulse modes, including pulsed nitrogen laser, semiconductor lasers in the near-infrared range, neodymium laser (first and second harmonic), sapphire laser, erbium, ruby and holmium laser, carbon dioxide laser.
SUBSTANCE: method for optical capturing of a particle in soft biological tissue is based on irradiating the surface of the tissue with a parallel beam of coherent laser radiation and determining the depth z of the captured particle in the tissue. The radiation wavelength λ* is selected depending on the depth z - for z<0.1 mm λ*=450 nm, for z≥0.1 mm λ*=1250·[1-exp(-z/1.35)], where λ* is given in nm and z in mm.
EFFECT: invention provides maximum particle capturing force with minimal heating of the tissue.
SUBSTANCE: claimed waveguide consists of accelerating electrode. The latter is composed of cylindrical tank made of nonmagnetic material wherein excited is HF axially-symmetric electromagnetic travelling E-wave. Besides, it comprises accelerating gaps between irises with apertures at central lengthwise axis of accelerating waveguide. Said irises are made of magnetic flux conducting material with magnets arranged there between to develop the lengthwise axially-symmetric magnetic field. The latter deflects in accelerating gaps in accelerating aperture area towards the accelerating waveguide central lengthwise axis. Extra focusing by radial magnetic pressure originates in accelerating gaps along with the focusing of the beam by crosswise component of E-wave accelerating electric field central lengthwise axis and retention of the beam of charged particles from angular divergence of horizontal component of created magnetic field. Said field results from deflection of magnetic field power lines towards accelerating waveguide central lengthwise axis. This downs the loss of charged particles at their acceleration and facilitates the ion beam current at accelerator outlet. Invention allows efficient acceleration both high-intensity ion beams and high-charge-density high-intensity ion beams.
EFFECT: increased current of accelerated ion beam at accelerator outlet, reliable operation, ease of production, lower costs.