Fiber-optic sensor system
FIELD: electro-optical engineering.
SUBSTANCE: fiber-optic sensor system can be used in physical value fiber-optic converters providing interference reading out of measured signal. Fiber-optic sensor system has optical radiation laser detector, interferometer sensor, fiber-optic splitter, photodetector and electric signal amplifier. Interferometer sensor is equipped with sensitive membrane. Fiber-optic splitter is made of single-mode optical fibers. Connection between fiber-optic splitter and interferometer sensor is based upon the following calculation: l=0,125λn±0,075λ, where l is distance from edge of optical fiber of second input of fiber-optic splitter to light-reflecting surface of sensor's membrane (mcm); λ is optical radiation wavelength, mcm; n is odd number within [1001-3001] interval.
EFFECT: simplified design; compactness; widened sensitivity frequency range.
4 cl, 1 tbl, 3 dwg
The invention relates to opto-electronic instrumentation and can be used in the construction of fiber-optic transducers of physical quantities, providing interference eat the measured signal. The most effective to use in the design of devices microtechnological performance, especially micro receiver sound signals (microphones, hydrophones, steel, phonendoscopes etc).
Known fiber optic sensor system containing a broadband radiation source, fiber light guide (SU), completed with the formation of the measurement and reference optical channels, the polarization sensor intermode interference, the photodetector connected to the processing unit and displaying information, the scanning deformer installed in the aircraft, and the control unit of the scanning deformers (EN 2036419, G 01 B 21/00, 1995). For use as a microphone fiber-optic sensor system contains a diaphragm sensing element on the inner surface of which a spiral is a fiber-optical light guide, one end of which is through a focusing lens connected to a source of monochromatic radiation, and the other photodetector (EN 2047944, H 04 R 23/00, 1995).
However, these structures are bulky and have low what setting because of reading information in the form of changes in the amplitude used the information signal.
Among the specialized fiber-optic sensor systems known designed for temperature measurement, contains, jointly executed on the basis of fiber-optic laser (OX), the excitation channels and the interference information retrieval, microresonator modulation of the radiation of the OX, the sensor and the processing unit and displaying information (EN 2110049, G 01 K 11/32, G 02 B 6/00, 1998). To increase the sensitivity, accuracy and stability of the system one end of the optical fiber, the OX is associated with modified autocollimator interposed between this end and the microcavity with the formation in the plane of the reflective surface of the microcavity light spot of a given size, and the second is the output (EN 2161783, G 01 K 11/32, 2001).
However, these technical solutions are complicated to manufacture and operate, as they require regular adjustment of the nodes of the microcavity and the collimator. In addition, they have a preferred area of use of the temperature measurement.
Also known fiber-optic sensor system for measuring displacements containing the optical radiation source, the interferometric sensor of micrometric movements, fiber optic splitter, made of single-mode optical fibers, sensors, equipped with a bandpass optical filter, the control device is istwo and the piezoelectric actuator, installed with the possibility of displacement of the interferometric sensor, where the output optical radiation source connected to the first input fiber optic splitter, a second input fiber optical splitter connected to the interferometric sensor for transmitting light from a source of optical radiation and reception of optical interference signal from the sensor, the output optical fiber coupler is connected to the photodetector, the output of the photodetector is connected to the input of the control device, and the output control device connected to the electrical input of the piezoelectric actuator (P.G. Davis, I.J. Busch, Maurer G.S. Fiber Optic Displacement Sensor. - Fourth Pacific Northwest Optic Sensor Workshop, May 6, 1998 SPIE VOL TBD Courtesy Optiphase, Inc.).
The disadvantage of this device is the complexity of the node displacement of the interferometric sensor and a narrow dynamic range (not more than 200 μm) measured the micrometric movements.
Closest to the claimed is a fiber-optic sensor system containing the optical radiation source with a coherence length 80÷120 μm, the interferometric sensor, equipped with a sensitive membrane, fiber optic splitter, made of single-mode optical fiber, a photodetector and amplifier electrical signal, where the output and the source of optical radiation connected to the first input fiber optic splitter, the second input optical fiber coupler is connected to the interferometric sensor for transmitting light from a source of optical radiation and reception of optical interference signal from the sensor, the output of the fiber optic splitter is connected with the optical input of the photodetector, and the output of the photodetector is connected to the amplifier input electrical signal. For locking the position of the working point fiber optic sensor system is also equipped with dual-channel interferometric Converter reference signal, and the amplifier is electrically connected with the inputs of the first and second channels interferometric transducer and optical interferometric output of the Converter is implemented with the formation of the optical feedback of the transmitter with interferometric sensor (US 5094534, G 01 B 9/02, 1992).
However, the prototype device has a narrow frequency range, sensitivity, lack of, in particular, to work as a microphone that is exacerbated by the inertia of the elements of the dual interferometric transducer. In addition, it is cumbersome and difficult to manufacture and operate, requires careful initial and periodic adjustment of optical channels.
The technical task proposed is the first device is a simplification and miniaturization design, as well as extending the frequency range of sensitivity.
The solution of the stated technical problem is that in the construction of fiber-optic sensor system containing a source of optical radiation, an interferometric sensor, equipped with a sensitive membrane, fiber optic splitter, made of single-mode optical fiber, a photodetector and amplifier electrical signal, where the output optical radiation source connected to the first input fiber optic splitter, a second input fiber optical splitter connected to the interferometric sensor for transmitting light from a source of optical radiation and reception of optical interference signal from the sensor, the output of the fiber optic splitter is connected with the optical input of the photodetector, and the output of the photodetector connected to the amplifier input electrical signal is introduced the following change: as a source of optical radiation used laser.
The use of laser in this design it is necessary to extend the range of "vidnosti" interference pattern due to the increase of the coherence length of the radiation (not less than 4 times in comparison with the prototype). This conclusion can be justified by analysis of the well-known formula
where lwhenthe coherence length of the radiation source microns;
l - distance from the end face of the optical fiber of the second input optical fiber coupler to the reflective surface of the membrane interferometric sensor (μm).
From inequality (1) we can conclude that
i.e. the "area of vidnosti" the more, the more the coherence length of the radiation source. The increase in the "zone of vidnosti" leads to expansion of the range of acceptable displacement sensitive membrane, i.e. no need to stabilize the position of the working point on the static characteristic of the system. This allows you to simplify the system by removing part of the design of the prototype circuit-locked loop. This option (claim 1 of the formula) hereinafter referred to as the minimum. When the technical implementation of the distance l set of terms definition of the interference pattern at the output of the photodetector.
The optimal value of the parameter l (variant according to claim 2 of the formula) is observed for the
where λ - wavelength optical radiation microns;
n is an odd number of experimentally established interval [1001÷3001].
Further adjustment of the operating point of the system is understood as a particular value of l.
Formula (3) is convenient for adjusting the position of the corresponding end of the optical fiber relative to the membrane using system precision positioning. It can also be used to verify the optimality of the configuration options according to claim 1.
The achieved increase in the "zone of vidnosti provides, if necessary, the system can receive audio signals, i.e. work as a microphone. In this case, it uses an amplifier of electric signals and membrane interferometric sensor which is sensitive in the audio frequency range (variant according to claim 3 of the formula). To work as part of the design of this microphone, it is advisable to use a sensor with a sensitivity of membrane not less than 0.1 nm/PA in this frequency range.
In the proposed system can be used in the laser of any of the structural design, for example, gas or solid. The most appropriate use of a semiconductor laser optical radiation source with an electric power from the current regulator, which allows miniaturizing design and to reduce its power consumption. This variant may further comprise a circuit precision control of the position of the working point with the control effect on the temperature of the laser on the static component of the feedback signal from the photodetector (4 formulas). This option is useful in terms of the effect on the sensor intense disturbances (temperature, pressure, VI is the radio, and others), causing the offset position of the working point of the system. As a thermoregulatory organ in the circuit precision control of the position of the working point, it is advisable to use a Peltier element (5 formulas), which gives the opportunity to operate in the heating mode of the laser and cooling.
The principle variations in claims 4 and 5 of the formula is based on the first use of the dependence of the emission wavelength of the semiconductor laser from the temperature of this source of optical radiation for adjusting the position of the working point on the static characteristic of the system.
Figure 1 shows the minimum version of the fiber-optic sensor system; figure 2 shows a case where the system by regulating the position of the working point; figure 3 presents the amplitude-frequency response of the microphone is made on the basis of the proposed fiber-optic sensor systems.
The table shows the values of the technical characteristics of samples minimum system option.
Fiber-optic sensor system (figure 1) contains a laser source 1 optical radiation, the interferometric sensor 2, equipped with a sensitive membrane 3, the fiber optic splitter 4, is made of single-mode optical fiber, the photodetector 5 and the amplifier 6 electrical signal. You are the od source 1 optical radiation connected to the first input fiber optic splitter 4, the second input optical fiber coupler 4 is connected to the interferometric sensor 2 is able to transmit light from the light source 1 to the optical radiation and reception of the optical interference signal from the sensor 2. The output optical fiber coupler 4 is connected with the optical input of the photodetector 5, and the output of the photodetector 5 is connected to the amplifier 6 electrical signal. Depending on the destination system to the output of amplifier 6 is connected a corresponding recording device 7 (oscilloscope, computer, indicator light, speaker and so on). The distance l from the output end of the optical fiber to the membrane 3 of the sensor 2 is installed on the interference pattern, or by using the apparatus in accordance with formulas (2) and (3).
Laser radiation from the source 1 through the coupler 4, enters the interferometric sensor 2. Part of this radiation is reflected from the output end of the optical fiber, and the other part of the light distance l, and reflected from the membrane 3 of the sensor 2, is fed in the reverse direction at the specified end of the same optical fiber. Due to the fact that the setting value l does not exceed 0,5lwhen, these light fluxes are added coherently, thus forming an interference pattern, which is output splitter 4 is supplied to fo detector 5, which is accepted by the amplifier 6 electrical signal and supplied from the output of the latter on the recording unit 7.
The test results are minimal variants of the target structures with sources of optical radiation at a wavelength of λ=1.55 and of 1.30 μm is presented in table 1. As can be seen from the table, the threshold sensitivity of the samples of fiber-optic sensor systems maximum when installing the end face of the optical fiber sensor 2 at the optimal distance from the membrane 3, defined by the formula (3), namely l=0,125λwhen n is an odd value of n in the range [1001÷3001]. In this case, the threshold sensitivity is 0,008÷0.01 nm at λ1.55 microns and 0.005÷0,006 nm at λ=1,30 mm. When the output over a specified range of variation n the sensitivity of the system decreases due to the loss of contrast of the interference pattern. For even values of n the system insensitive due to the ingress of the working point on the insensitive area cosine interference dependence of the output signal of the system from the l value.
In a variant of the microphone (p.3 formula) distinguish between static and dynamic characteristics of the fiber-optic sensor systems. The static characteristic is a steady-state value of the output signal of the photodetector depending on the position of the working point for missing and interference. Dynamic characteristic is formed as a result of actions taken by the sound signal and depends on the amplitude-frequency characteristics (AFC) of the membrane of the sensor. Figure 3 shows the experimentally captured response fiber-optic sensor systems with wavelength λ1.55 microns of the semiconductor laser 1 with a capacity of 2 mW and a sample of the membrane of the sensor 3 a sensitivity of 1.5 nm/PA. The frequency response of such a system in the audio frequency range is uniform. Its irregularity is less than 3 dB with an average value of the frequency response equal to 135 dB.
The best option system, equipped with a semiconductor laser source 1 optical radiation with electric power from the current regulator, further comprises circuit 8 precision adjusting the position of the working point with the control effect on the temperature of the laser on the static component of the feedback signal from the photodetector, comprising an automatic controller 9 with the Executive mechanism and the regulatory body 10 (figure 2, item 4 of the formula). The input of the regulator 9 is connected with the output of the photodetector 5 directly, as shown in figure 2, or via the amplifier 6, the output of the controller 9 is connected using the enclosed structure of the actuator with the expansion body 10 mounted with the possibility of changing the temperature of the laser 1. temperature change of the laser 1 leads to a change in wavelength λ its radiation relative to the nominal value to compensate for the deviation of the operating point under the action of external interference on the sensor 2.
As the expansion body 10 may be used corresponding to the heater, for example, made in the form of nichrome spiral. It is also possible inclusion of the element 10 in the circuit of generator current regulator feeding the laser 1. The most useful within the expansion body 10 to use the Peltier element (5 formulas). This gives the opportunity to operate in the heating mode and the cooling laser, which expands the range of control actions.
As explained by the description, examples and graphics application, the use of the proposed fiber-optic sensor systems in comparison with the prototype allows to simplify and miniaturizing design of the target system by single execution path interferometric measurements and exceptions bulky Electromechanical node-locked loop position of the working point. In addition, there is an extension of the frequency range sensitivity, as evidenced by the frequency response variant of the system as a microphone. Achieved the life of the system in terms of the interference due to the first sales compensation interference by changing the wavelength of the radiation source.
T is Henichesk result derived from these results is to reduce the cost of the system by simplifying its construction and alignment.
1. Fiber-optic sensor system containing a laser optical radiation source, the interferometric sensor, equipped with a sensitive membrane, fiber optic splitter, made of single-mode optical fiber, a photodetector and amplifier electrical signal in which the output optical radiation source connected to the first input fiber optic splitter, a second input fiber optical splitter connected to the interferometric sensor is able to transmit light from the optical radiation source to the interferometric sensor, and the output of the photodetector is connected to the amplifier an electrical signal, characterized in that it uses a laser source with high coherence, the output of the fiber optic splitter directly connected with the optical input of the photodetector, and the connection of fiber-optic splitter to the interferometric sensor is made of calculation
where l is the distance from the end face of the optical fiber of the second input optical fiber coupler to the reflective surface of the membrane integration of parametricheskogo sensor (μm);
λ - wavelength optical radiation microns;
n is an odd number from the interval [1001-3001],
for simultaneous reception of the optical interference signal from the sensor and transmit this signal to the input of the photodetector.
2. Fiber optic sensor system according to claim 1, characterized in that it is an amplifier of electric signals and membrane interferometric sensor are made sensitive in the audio frequency range.
3. Fiber optic sensor system according to claim 2, characterized in that when used as a source of optical radiation of a semiconductor laser it further comprises a circuit precision control of the position of the working point with the control effect on the temperature of the laser on the static component of the feedback signal from the photodetector.
4. Fiber optic sensor system according to claim 3, characterized in that the contour precision adjusting the position of the working point as the expansion body is equipped with a Peltier element.
FIELD: optical engineering.
SUBSTANCE: device has optically connected single-frequency continuous effect laser, photometric wedge, electro-optical polarization light modulator, first inclined semi-transparent reflector, second inclined semi-transparent reflector and heterodyne photo-receiving device, and also second inclined reflector in optical branch of heterodyne channel, high-frequency generator, connected electrically to electro-optical polarization modulator, direct current source, connected to electrodes of two-electrode vessel with anisotropic substance, and spectrum analyzer, connected to output of heterodyne photo-receiving device.
EFFECT: possible detection of "red shift" resonance effect of electromagnetic waves in anisotropic environments.
FIELD: engineering of devices for displaying and processing information.
SUBSTANCE: bi-stable liquid-crystalline element includes a layer of liquid crystal or liquid-crystalline material with inversion of dielectric anisotropy sign, positioned between two substrates with electrodes on their internal planes, processed for direction of liquid crystal, or covered by directing layers. Polarizers or other means holding the place of the latter serve for determining difference between switched bi-stable states during feeding onto electrodes of special electric signals in form of pulse packets with electric voltage frequency less or more than frequency of inversion of liquid crystal dielectric anisotropy sign. Different modes of bi-stable switching of liquid crystals may be achieved depending on direction of liquid-crystalline directing device on substrates.
EFFECT: improved electro-optical and operation characteristics of liquid-crystalline element.
3 cl, 13 dwg
FIELD: optical engineering, in particular, engineering of counter-dazzling means, possible use for screening eyes of driver from dazzling light, in particular from cars moving in opposite direction.
SUBSTANCE: counter-dazzling glasses have frame with glasses, protective screen with cells and a matrix of light-sensitive elements, electrically connected to protective screen, additionally included is infrared eye pupil position indicator, generating signal under effect from infrared radiation from pupil, gate matrix with normally darkened cells and slit formed in it imitating eye pupil position, adjusting assemblies. Gate matrix is electrically connected to infrared pupil position indicator through adjustment assemblies, is mounted with possible letting of dazzling radiation through slit formed in it onto matrix of light-sensitive elements and following transmission of signal to it for darkening of protective screen cells for protecting pupil from dazzling radiation.
EFFECT: possible alteration of light-protective layer of glasses with consideration of diameter and mobility of driver eye pupil.
FIELD: measurement technology.
SUBSTANCE: universal mirror has mirror, case, holder and radiation receiver. Assembly has at least two mirrors and at least one polarization filter and device for mounting mirrors in series into working position. Polarization filter is fixed onto at least one mirror. Assembly is made for installation of mirror without filter into working position, or at least one mirror with at least one polarization filter. Mirror being at working position provides ability of reflecting of incident radiation to radiation receiver.
EFFECT: improved efficiency at natural light.
14 cl, 10 dwg
FIELD: optical engineering.
SUBSTANCE: invention relates to nonlinear optics and consists in that nonlinear liquid is composed of fluoroindium complex of octaphenyltetraazaporphyrin, 0.053-0.210 g/L, concentrated hydrochloric acid, 0.720-6.000 g/L, and chloroform.
EFFECT: increased coefficient of weakening potent laser UV emission by nonlinear liquid at linear transmission coefficient of weak UV emission at least 50%.
FIELD: engineering of displays.
SUBSTANCE: to decrease number of external outputs of screen in liquid-crystalline display, containing two dielectric plates with transparent current-guiding electrodes applied on them, each electrode of one plate is connected to selected electrode of another plate by electric-conductive contact, while each pair of electrodes is let out onto controlling contact zone, and electrodes, forming image elements of information field of screen, on each plate are positioned at angle φ similar relatively to external sides of plates, while angle φ satisfies following condition: 10°≤φ≤85°.
EFFECT: decreased constructive requirements for display.
4 cl, 4 dwg, 1 tbl
FIELD: optical instrument engineering.
SUBSTANCE: modulator has non-monochromatic radiation source, polarizer, first crystal, first analyzer, and second crystal, second analyzer which units are connected together in series by optical coupling. Modulator also has control electric field generator connected with second crystal. Optical axes of first and second crystals are perpendicular to direction of radiation and are parallel to each other. Axes of transmission of polarizer and analyzers are parallel to each other and are disposed at angle of 45o to optical axes of crystals.
EFFECT: widened spectral range.
FIELD: the invention refers to optics.
SUBSTANCE: it may be used for protection of photo receiving devices from laser blinding by radiation of excessive intensity and at creation of non-linear optical limiters of radiation designed for protection of eyesight apparatus from damaging by laser radiation, for making low-threshold of optical switches. The purpose of the invention is in decreasing of energy threshold of the beginnings of non-linear -optical response of the environment. The non-linear -optical environment contains inorganic crystalline nanoparticles placed in transparent environment with linear optical characteristics. The nanoparticles consist of a nucleus not holding a shell having absorbing centers for example admixtures or defects. The shell and the nanoparticles are made of the same material. At impacting of laser radiation on non-linear-optical environment, photo generation of non-equilibrium electrons begins in the shell of the nanoparticle having defects out of an impurity zone into a conducting band. The changing of concentration of carriers lead to appearance of non-linear addition to the refraction index and absorbing of the shell. At photo generation of carriers a gradient of their concentration originates between the shell and the nucleus and as a result their diffusion begins deep into the nucleus. At that the thickness of the layer containing non-linear addition to the refraction index and absorption grows. As a result dielectric permittivity of a nanoparticle changes and that leads to changing of the section of its absorption and dispersion.
EFFECT: non-linear optical effect becomes apparent in limiting radiation.
FIELD: non-linear integral and fiber optics.
SUBSTANCE: device can be used for high-speed data processing transmitted by electromagnet radiation. Modulator has weak ferromagnetic material transparent plate disposed between coils having aiding connection; coils are connected and in pairs. Coils are connected with magnetic pulse oscillator. Ferromagnetic plate is tightly fixed between magnets for forming stable rectilinear domain boundary inside uniformly magnetized domain area of coils. Mechanical pressure aids are connected to plate for forming constant mechanical pressure which pressure together with influence of pulse magnetic field, created by coils, induces elastic induced magnetization in a reverse sense of weak ferromagnetic plate. Speed of operation can be increased till optical range frequencies. Power of control reaches of 1E, time of switch doesn't exceed a few tens of ns.
EFFECT: improved speed of operation.
FIELD: measuring equipment.
SUBSTANCE: element has liquid crystal layer, encased between two substrates with transparent electrodes, while at least one of electrodes is divided on stripes, widths of which are picked on basis of Fresnel lens forming law, and output mask with slits, combined with focuses of Fresnel lenses. Element additionally has input mask with slits, raster capacitor, second electrode is divided on stripes, widths of which are picked from same Fresnel lens forming law, focal distances of both Fresnel lenses are set equal, but for different wave lengths.
EFFECT: higher brightness of image.
FIELD: the invention refers to instrument making.
SUBSTANCE: the interferometer is fulfilled in the shape of a photoreceiver. It has an interference-sensitive element on a transparent sublayer and a reflector. It also has an N number of interference-sensitive elements located along the edge of the key where N is a positive number.
EFFECT: allows to receive electronic measurements of an interferogram without mechanical scanning of the difference of unterferometer's motion.
FIELD: optical engineering; measurement engineering.
SUBSTANCE: polarization interferometer for measuring spatial changes in refractivity of transparent media has lighting unit mounted in series with interference-polarization unit composed of polarizer, analyzer and interfering beams unit disposed between polarizer and analyzer. Interferometer also has photo-registering device. As lighting unit the unit is chosen which forms parallel beam. Interfering beam splitter of interference-polarization unit is made in form of member with flat-parallel working faces. The member is cut of single-axis crystal for inclination at two mutually perpendicular planes, which are in turn perpendicular to plane of transmission cross-section of interferometer's optical system.
EFFECT: simple and reliable measurement of changes in refractivity of transparent media.
4 cl, 2 dwg
SUBSTANCE: interferometer devices offered are supposed to be used for examining internal structure of object by means of optical coherent tomography method when ability of controlling location of view area boundary is provided as well as ability of correction of distortion of tomography image of cross-section of object which correction is caused by aberration of optical path length for low-coherent optical radiation directed onto object to be examined if aberration is provided by lateral scanning. According to versions of the device, one or two fiber-optic controlled scanners offer the service of scanning of coherent window of low-coherent optical radiation deep inside tested object within view area, the service of control of view area boundary location and service of compensation of optical path length aberration for low-coherent optical radiation directed onto tested object if aberration is provided by lateral scanning. The services are performed due to corresponding control voltages. According to preferable version of interferometer device, fiber-optic controlled scanner is realized in form of fiber-optic piezoelectric controlled delay line.
EFFECT: widened range of interferometer devices; simplified exploitation.
43 cl, 5 dwg
FIELD: systems for identification of objects.
SUBSTANCE: device can be used for reading out stamp applied onto surface of pipe. Device has optical head connected with computer through image introducing printed circuit board. Optical head has two optical channels. First channel has first projection objective with linear magnification of Bet1, focal length f1, angle of field of view tgW1 and relative distortion δYob1 within whole angle of field of view and first CCD linear array which is disposed along pipe. Second optical channel has second projection objective with linear magnification Bet2, focal length f2, angle of field of view tgW2 and relative distortion δYob2 within whole angle of field of view and second CCD linear array disposed in perpendicular to axis of pipe. The following conditions are met: Bet1= αN1/Dmax, Bet2>5Bet1, tgW1=Dmax/L, tgW2=0,2Dpipe/L, αN1≤2f'1tgW1, d2≤2f'2tgW2, δYob1<1/N1, δYob2<1/N2, where α is distance between substrates of first CCD linear array, L is distance from optical head to pipe, d2 is length of second CCD linear array, N1 and N2 are number of elements in first and second CCD linear arrays, Dmax is width of scanned area at the surface of pipe.
EFFECT: improved precision.
FIELD: engineering of interference measuring devices.
SUBSTANCE: device is made with possible input of optical radiation into second port of optical interference meter while providing for identical nature of modes of optical radiations coming from first and second ports of optical interference meter, and identical nature of optical radiations modes, coming from first and second ports of optical interference meter into referent shoulder of optical interference meter. Device may include one or two sources of optical radiation. When using one source device has polarization branching device, mounted behind the source along movement direction of radiation. One of outputs of polarization branching device can be made in form of, for example, Michelson interference meter, containing three-port commutators, or in form of Mach-Zehnder interference meter. Utilization of two sources of optical radiation allows also to perform multiplexing without spectrum losses of power.
EFFECT: improved effectiveness of utilization of optical radiation source power.
23 cl, 6 dwg
FIELD: measurement technology.
SUBSTANCE: holographic unit for Measuring Value of stress-deformed condition of object has base, coherent radiation source, aids for representing interference pattern onto surface of object, radiation receiver and unit for setting stress-deformed condition which also has drilling unit. Unit for setting stress-deformed condition is provided with post which embraces base and has detachable joint with the base. The unit also has bore rod provided with clamp. Post is made to have object being fixed onto its surface and is provided with bushing having round jig hole. The hole is made in such a manner that its axis crosses axes of incident and reflected beams at the same point. Bore rod conjugates with post through round jig hole. Repeated measurements are excluded due to reduction in mechanical influence onto base of device and members of its optical system during drilling material of object and operation of mechanical gate.
EFFECT: improved precision of measurement.
6 cl, 5 dwg
SUBSTANCE: device has coherent emission source, first condensing filter, consisting of condensing lens, first and second light-splitting elements, objective, interferometer, consisting of standard and controlled surface, device for measuring optical beam drive length, first projection system, registering block and system for processing interference image, system for projecting auto-collimation images. Also provided is additional condensing filter, mounted in focal plane of objective, device for changing optical length of beam drive is positioned behind the laser, made in form of two transparent diffraction grids, one of which can move in direction, perpendicular to grid rows, first diffraction grid divides emission on two beams, each of which gets on to lenses of condensing filters, while controlled and standard surfaces are deflected relatively to normal line to optical axis.
EFFECT: broader functional capabilities, higher efficiency.
FIELD: measuring engineering.
SUBSTANCE: method comprises directing a coherent light beam at the surface to be tested, producing and recording interferogram of the light path difference, and processing the interferogram. The tested and reference surfaces are exposed to the second coherent light beam, and the second interferogram of the light path difference is created. The second interferogram is provided with the additional light path difference with respect to that of the first interferogram, which is equal to the one fourth of the beam wavelength. The light path difference of the first interferogram is determined at specific points of the surface to be tested from the signal of illumination in one of two interferograms. The device comprises source of coherent light, first filter-condenser, first and second light-splitting units, interferometer composed of tested and reference surfaces, unit for measuring optical length of the beam, first projecting unit, recording unit, observing unit, and unit for processing the interferogram. The device also has two light-splitting units between which two pairs of transparent diffraction lattices are interposed. The filter-condenser, the second light-splitting unit, and λ/4 lattice are arranged in series in the direction of the beam.
EFFECT: enhanced precision.
4 cl, 8 dwg
FIELD: optical engineering.
SUBSTANCE: flat object is illuminated with coherent radiation to measure movement at the plane and angle of inclination of flat part of surface. Radiation dissipated by object is directed to optical system, which carries out integral optical transformation of wave field. Two inverse Fourier-Frenel transforms are used on the base of collecting lens. Intermediate and final results are fixed onto photographic plates, which form specklegram and interferogram. Object and photographic plate are disposed at different varying distances from lens. Values to be measured are divided and required sensitivities of measurement are found, which depend on focal length f of first lens, parameters of first optical inverse Fourier-Frenel transform φ, δ and on focal length f second lens and parameter α of second optical inverse Fourier-Frenel transform.
EFFECT: varying sensitivity; widened range of measurement of shift and inclination.
FIELD: hologram interferometering of a flat object.
SUBSTANCE: the mode of hologram interferometering of a flat object is in making of a double exposure hologram of the surface of the object in counter rays. Then two images of the surface of the object reconditioned by the hologram are directed in an optical system in which one after another two direct Fournier-Frenel transform are carried out, interferograms of the images of the surface of the object are fixed. The object and the interferogram are located at such distances from the lenses that the in-focus image of the surface of the object in the surface of the interferogram is made and at the expense of variations of these distances and the focal distances of the lenses, measured sizes are divided and wishful sensitivities of measurements of travel and inclination constant along the whole surface are chosen.
EFFECT: ensuring constant surface and variable sensitivity, increased range of measuring of travel and inclination.
FIELD: control-mounting systems.
SUBSTANCE: device has laser fixed in body, images forming device made in form of intersecting filaments. Body is made in form of hollow prism, provided with cone at the end. Upper portion of cone is combined with center of apertures provided in coordinate lines system. Body is mounted with possible angular displacements around aperture center. Forming device filaments are made non-transparent and fixed in frames inserted in system. Frames are placed with possible displacement independently from one another in direction perpendicular to filaments.
EFFECT: higher precision.