Fotomastera pair of optical prisms for laser gyro with a prism of total internal reflection
(57) Abstract:Fotomastera pair of optical prisms for laser gyro with a prism of total internal reflection relates to gyroscopes. Fotomastera pair of optical prisms for laser gyro with a prism of total internal reflection contains the first prism with two refracting faces and one reflecting face of the second prism with input, output, reflecting and mounting faces. There is an optical contact between the mounting face of the second prism and the reflecting face of the first prism out of the field of generation of the laser gyro. The value of the distance from the reflecting face of the first prism to the input face of the second prism varies smoothly from zero from the ribs formed by the installation and the input faces of the second prism, up to three wavelengths at the edges formed by the input and second reflecting faces of the prism. The invention improves the level of accuracy of the laser gyroscope operating in a wide temperature range. 4 Il. The technical field to which the invention relates.Laser gyroscope; IPC G 01 C 19/66.Known fotomastera pair of optical prisms laser gyroscope, which is protot the second resonator of the ring laser and the second prism, having a constant transmittance in the region of the iris radiation and providing hard irised radiation beam, and the second prism is attached to the first adhesive . Under strict irised means is stopped down a beam of laser radiation, in which a small displacement of the beam (about 0.05 mm), or a change in the diameter of the beam corresponds to a significant (about 100%) change in insertion of the diffraction loss. In the temperature range of pereustanovki can reach values of the order of 0.1 mm Hard irised leads to lower precision laser gyroscope in the presence of perestanovok different origin. Adhesive bonding does not provide sufficient mechanical rigidity and strength of the connections, especially over a wide temperature range, which is not constant gap between the first and second prisms, and thus transmittance.The invention aims to improve the accuracy of the laser gyroscope operating in a wide temperature range, by reducing at least on the order of the steepness of the dependence of the diffraction loss from the input aperture deeper into the field of generation.the face AD) 4. Prism 5 has a reflective face (face AD) 6 input line 7 and the output line 8. The line 6 is perpendicular to the faces 7 with a small deviation from perpendicularity (1') to form the interference pattern. The faces 6 and 7 form an interference edge. The second prism is attached to the first gap glue out-of-area generation, while on the entrance face of the second prism has a coating that specifies the size of the gap to 3 wavelengths between the input face of the second prism and the reflective face of the first prism. The input line partially overlaps the spot of generation on the reflective face of the first prism. The presence of a small gap leads to the phenomenon of violation of air defense, which is that under the conditions of total internal reflection of the radiation is reflected, however not completely. Due to this phenomenon the input face of the second prism, partially overlapping spot generation on the reflective face of the second prism displays a small (about 0.01%) part of the radiation counter propagating waves radiation of a ring laser, simultaneously performing the function of the iris radiation. Derived from the resonator radiation one of the opposing waves propagated to output the second prism so, that reflected radiation is propagated to the output face of the second prism with a small angle (about 1') relative to the radiation of the first wave. In the plane of the photodetector is thus formed running interference pattern, which then retrieves the parameters of rotation of the gyroscope.This design work in a wide range of temperatures for the following reasons: significant thermal pereustanovki of the order of 0.1 mm, resulting in change of the diffraction properties photomedicine pair of prisms and the power of the output radiation; unstable properties of the adhesive, leading to instability of the gap between the first and second prism pair, which also changes the diffraction properties of the pair and the power of the output radiation.All these physical phenomena lead to changes in the difference of the intensities for the oncoming waves. The difference between the intensities leads to additional frequency difference counter will be described with the formula (15.6) from . This frequency difference results in an error, called the shift of the zero laser gyroscope. When perestroika (thermal, mechanical) diffraction conditions are changed differently for the oncoming waves, which leads to additional change inher temperature shift becomes zero variable, which reduces the accuracy of the laser gyro.To stabilize the shift of the zero of the necessary design photomedicine pair of prisms that is less sensitive to perestroika.Offer fotomastera pair of prisms shown in Fig. 2. The design introduces the installation face 9 and the second prism is mounted optical contact that faces the reflective face of the first prism. The installation and the entrance face of the second prism to form a mounting edge. The input face of the second prism completely covers the spot of generation, and the size of the gap varies smoothly from 0 at the installation ribs up to 3 (depending on the required transmittance of radiation) wavelength radiation interference ribs. Optical contact between the mounting face of the second prism and the reflecting face of the first prism is an essential characteristic in connection with the fact that in optical contact, first, there is a new property - the intermolecular interaction between the mounting face of the second prism and the reflective face of the first prism; secondly, the reflection coefficient of the reflecting face of the first prism is close to zero in the area of optical contact, which is the basis for selecting seismi.The proposed design provides the output radiation due to the effect of violation of PVO small (up to 3 wavelengths) variable gap between the pair of prisms. Soft irised is provided by the gradient of the transmittance arising due to the variability of the gap. Under the soft irised means is stopped down, at which a small displacement of the beam or small change in the diameter of the beam corresponds to a small variation of insertion of the diffraction loss. Due to their ability to irised there is no need to specifically enter the aperture, which reduces the diffraction loss and backscatter radiation. The bias stability of the radiation is provided by mounting the prisms hard and durable optical contact.Thus, the proposed combination of three essential features: the installation face; an optical contact between the mounting face of the second prism and the reflective face of the first prism; a smooth change in the distance from the reflective face of the first prism to the input face of the second prism from zero at the installation faces up to three wavelengths in the interference ribs of the second prism; gives a new property: povyshennogo positive effect.List of drawings and other materials:
Fig. 1 is a drawing of a prototype photomedicine pair of prisms,
Fig. 2 - drawing of the proposed photomedicine pair of prisms, indicated the relative position of the pair of prisms, the optical axis,
Fig. 3 is a graph showing the distribution of the reflection coefficient of the radiation in the cross-section of the gap,
Fig. 4 is a graph of sensitivity periostracum for the proposed mixing prism and prototype.Information confirming the possibility of carrying out the invention.Design photomedicine pair of prisms shown in Fig. 2. In Fig. 3 shows the distribution of the energy reflection coefficient in the cross section in the case of the wedge-shaped gap, i.e. a gap, which gap varies linearly from 0 at the mounting edge of the second prism to 3 wavelengths from the interference of the ribs of the second prism. In Fig. 3 the X-coordinate corresponds to the distance from the middle of the wedge-shaped gap.The wedge-shaped gap has a variable transmittance in the cross section of the gap.The energy dependence of the transmittance of the radiation from the gap value is
< / BR>ik2zd = ;
< / BR>< / BR>where - coefficient of skipping the radiation inside the first prism;
1- the dielectric constant of the material of the prisms;
2- the dielectric constant of air;
the wave vector of the radiation in the prisms;
- wavelength radiation.To acknowledge receipt of the above technical result produced by comparative calculations of sensitivity to perestroika. Sensitivity to perestroika is defined as the ratio of the change of insertion loss to the displacement of the optical beam at thermal perestroika. The results of the calculations are shown in Fig.4 for the prototype and the proposed design. In Fig.4 S - value pereustanovki, A change of insertion loss.It is obvious that the sensitivity to perestroika significantly lower for the proposed mixing prism.Literature
1. II St. Petersburg international conference on gyroscopic technology and navigation. H. 1. - St. Petersburg, 1995, S. 125-127.2. Sager, S., Klimontovich Yu L, Landa P.F. and other Wave and fluctuation processes in lasers/ Ed. by Y. L. Klimontovitch - M.: Nauka, 1974. Fotomastera pair of optical prisms for laser gyro with a prism of total internal reflection, including PE the tourism contains input, output and reflecting faces, characterized in that the second prism is introduced to an installation face, there is an optical contact between the mounting face of the second prism and the reflecting face of the first prism out of the field of generation of the laser gyro, and the value of the distance from the reflecting face of the first prism to the input face of the second prism varies smoothly from zero at the edges formed by the installation and the input faces of the second prism, up to three waves of radiation fins formed by the input and second reflecting faces of the prism.
FIELD: engineering of laser gyroscopes.
SUBSTANCE: laser gyroscope includes circular laser, electronic block and swaying system on immobile base, possible use for measuring its angular speed. Method includes measuring increments of turning angle θ during query time l/fd and determining speed of rotation of gyroscope and systems based on it in accordance to following formula: where θi - increment of rotation angle, i - number of measurement θi, N - number of measurements θi, fd - number of measurements per second.
EFFECT: substantially reduced error caused by mechanical oscillations of gyroscope relatively to immoveable base, and reduced discontinuousness of angular speed measurement without usage of additional optical elements in its structure.
SUBSTANCE: resonator (1) features optical loss adjusted according to the intensity difference of contradirectional modes and depending on direction of emission propagation. The optical loss is evoked by an optical unit including polarisation element (71), first element (7) with reversible effect on the wave polarisation, and the second element (8) with irreversible effect on the wave polarisation, so that at least one of the two effects is adjustable.
EFFECT: reduced resonator instability.
15 cl, 10 dwg
FIELD: physics, measurement.
SUBSTANCE: invention is related to solid-state laser gyroscopes. Gyroscope comprises annular optic resonator that comprises at least three mirrors, solid-state active medium and feedback system, which contains at least two acoustic optical modulators, and which may be arranged as monolithic.
EFFECT: reduced instability of optic resonator due to controlled optical losses that depend on direction of distribution, which are introduced into resonator (1) with the help of acoustic optic devices.
10 cl, 9 dwg
FIELD: physics, measurement.
SUBSTANCE: invention concerns measurement equipment, particularly gyroscopic converters of angular velocity based on annular lasers. Mobile unit if laser gyrometre includes optic unit, mobile part of mechanical oscillator, connecting posts with central hole in each, filler between posts and through holes in optic unit, in which posts are inserted. Posts feature external annular grooves with through orifices in each. Damper is screwed in central hole of each post. Central hole of each post, annular grooves and space between through hole in optic unit and post are filled with filler represented by elastic material, such as Viksint.
EFFECT: enhanced reliability of optic unit junction to mobile part of mechanical oscillator.
FIELD: instrument engineering.
SUBSTANCE: invention refers to measurement equipment, namely to gyroscopic converter of angular rate at ring lasers. Unit of laser gyroscopes contains base frame, optical block with laser gyroscopes, mechanical oscillations sensitising device. In the unit there are six laser gyroscopes, two laser gyroscopes at each of three axes of the unit. At the base frame there are three mutually perpendicular walls. In optical block side planes that form one trihedral angle there are holes. The depth of the holes is more than the distance from the plane to the optical block centre. In the centre of optical block there is a ball. Resonant cavities that are included into holes of optical block planes and screwed to the corresponding base walls lean on the ball. At the edge of each resonator there is flat area and cavity that has the form of a ball.
EFFECT: increase of laser gyroscope unit safety and improvement of angular rate measurement accuracy.
FIELD: instrument engineering.
SUBSTANCE: invention refers to solid gyrolasers. In order to decrease optical radiation instability of such lasers it is proposed to implement optical intensification into resonant cavity (1). Optical intensification is controlled by installation of optical block containing anisotropic laser medium (19), two optical elements (7) and (8) of nonreciprocal action. Each element influences polarisation of optical modes spreading out opposite each other. At least one of these two effects is temporary and, thus, allows implementing of controlled optical intensification that depends upon the direction of optical modes opposite spreading.
EFFECT: stabilised solid gyrolaser with anisotropic laser medium.
4 cl, 9 dwg
FIELD: physics, measurements.
SUBSTANCE: invention is related to the field of metering equipment, namely to devices for measurement of angular velocity arranged at ring lasers. Laser gyroscope comprises resonator, reflectors, device for generation of optic waves in resonator, system for control of resonator perimetre with electronic circuit and device for adjustment of resonator perimetre comprising reflector. On one side of resonator the first deepening is arranged with surface in the form of sphere surface part, on the second side of reflector there is the second deepening arranged with surface in the form of sphere surface part, radius of which is at least significantly lower than the first deepening surface sphere radius. In the second deepening metal cover piece is inserted, which follows shape of the second deepening in reflector and connected to outlet of electronic circuit.
EFFECT: higher manufacturability and reduced complexity of making the device for adjustment of resonator perimetre with application of reflector.
2 cl, 4 dwg
FIELD: physics; optics.
SUBSTANCE: invention relates to solid-state laser gyroscopes used for measuring speed of rotation or angular positions, particularly in aeronautics. Proposed is an optical architecture of a laser cavity based on common maintenance of the scaling factor, temperature stability of which is 4A/λL, where L and A are optical length and area of the laser cavity respectively, and λ is the average wavelength of the laser in Sagnac effect. Each parametre may vary with temperature.
EFFECT: design of a solid-state laser gyroscope with stabilised scaling factor.
5 cl, 1 dwg
FIELD: physics; optics.
SUBSTANCE: invention relates to solid-state laser gyroscopes used in inertial systems, particularly in aviation system. The gyroscope has semiconductor medium and is formed by joining discrete elements to each other, that way providing possibility of making relatively large resonators which allow for achieving the required measurement accuracy. More specifically, the gyroscope has an annular optical resonator and an amplifier semiconductor medium with a vertical structure external resonator which has flat and parallel amplification areas, where dimensions of the resonator essentially exceed dimensions of the amplifier medium and this amplifier medium is used in reflection mode.
EFFECT: possibility of making relatively large resonators which allow for achieving the required measurement accuracy.
9 cl, 8 dwg
FIELD: measuring equipment.
SUBSTANCE: invention is related to solid-state laser gyroscopes intended for measurement of rotation speed or relative angular positions, and may be used in particular in the field of aeronavigation. Gyroscope comprises, in particular, mutual (6, 9) and nonmutual (5, 8) spinners of polarisation plane arranged with provision of two opposite optical modes distribution in resonator (1), frequencies of which differ to a sufficient extent for prevention of modes synchronisation.
EFFECT: invention makes it possible to produce "fully optical" stable solid-state laser, which does not have movable elements and dead bands.
4 cl, 7 dwg
FIELD: visual devices; range finders; IR optical systems.
SUBSTANCE: prism unit has prism and two structure identical wedge compensators mounted in front of input and behind output faces of prism for rotation around axis belonging to main cross-section of prism. At initial position the input face of second compensator is parallel to output face of first compensator. Compensator can be composed of two like wedges glued together. Wedges are made of materials having different dispersion coefficients or refractivity factors. The wedges are connected in such a manner that bigger base of one wedge at main cross-section has to be prolongation of smaller base of the other wedge.
EFFECT: improved precision of prism unit.
8 cl, 1 dwg
SUBSTANCE: reflecting prism can be used in projection displays and other optical devices. Reflecting prism for bringing plane of polarization in rotation is made of optically transparent material and it has shape of rectangular parallelepiped with three truncated angles in form of prisms. Isosceles triangular bases of those prisms belong to mutual perpendicular sides of parallelepiped. One side face of any prism has to be cutting plane which forms one of three working surfaces of reflecting prisms. Working surfaces of prism are disposed at angle of total internal reflection and they are made for series reflection of incident light beam which cones to reflecting prism at angle of 90 degrees to its side to form exit light beam being co-linear to incident beam. Working surfaces at reflection of beam provide turn of plane of polarization.
EFFECT: improved reliability of operation.
6 cl, 3 dwg
SUBSTANCE: invention relates to medical equipment, and particularly to metering systems for mouth cavity. System comprises registering device, comprising photodetector and light source, interface joined to registering device and comprising light-conducting prism, in which there is a surface of registration and surface of image generation. In process of use surface of registration is brought closely to or in contact with surface of chewing, front surface or one of side surfaces of metered row of teeth or into mouth cavity, and surface of image generation is joined to registering device. At the same time registering device is arranged with the possibility of disconnection from interface, prism represents Bauernfind prism, and source of light emits white light. Source of light is located opposite to one of prism sides and is arranged so that it may illuminate metered row of teeth or mouth cavity continuously or for a short period of time.
EFFECT: device application makes it possible to increase viewing angle to obtain image of the whole surface of row of teeth or whole mouth cavity in a single operation.
9 cl, 5 dwg
SUBSTANCE: prism is composed of three Iceland spar crystals glued together, the optical axes of which are parallel to the input face of the prism and to each other. The refraction index of the glue is less than the refraction index for an ordinary ray. The crystals are cut at an angle which provides total internal reflection of an ordinary ray from the gluing line. The middle crystal is rhomb-shaped in the principal cross-section. The angle between the faces of the crystals, which provides total internal reflection of an ordinary ray, is greater than where nk is the refraction index of the glue used to glue the crystals; no is the refraction index for an ordinary ray in Iceland spar; and less than where ne is the refraction index of an extraordinary ray in the crystal. Side crystals have a symmetric shape relative the centre of the cross-section of the middle crystal, and the output face is perpendicular to the reflected ordinary ray.
EFFECT: high accuracy of linking the direction of the polarisation plane with the normal to the optical surface of the polariser.
4 cl, 4 dwg
SUBSTANCE: multibeam interferometer has two reflective semitransparent coatings. The zone where the interference pattern is formed is formed by a refracting prism having a totally-reflecting face and which is a common substrate for the two reflective semitransparent coatings. The prism has two identical refracting angles which are formed by a face with total internal reflection and faces with the reflective semitransparent coatings.
EFFECT: enabling mechanical and optical stabilisation of the multibeam interferometer.