CN101782593A - Double Y-shaped cavity double-frequency laser accelerometer - Google Patents
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Abstract
The invention discloses a double Y-shaped cavity double-frequency laser accelerometer, which belongs to the technical field of laser and precision measurement, and comprises an optical module, a working point selection and control module, a signal acquisition and processing module and the like. The optical module consists of two symmetric Y-shaped cavity double-frequency lasers and a novel gas diaphragm capsule. The gas diaphragm capsule is used as a primary acceleration sensing element to convert the change of an input acceleration first into the change of the refractive index of a sensing gas in the gas diaphragm capsule and then into the beat frequencies of the Y-shaped cavity double-frequency lasers and to output the beat frequencies; then a double Y-shaped cavity structure is used to differentiate the beat frequencies of the two Y-shaped cavity double-frequency lasers; and thus, a final output signal is obtained. The working point selection and control module is used for selecting and controlling the working point of the accelerometer, and a light intensity difference method is used to stabilize the frequencies of the double-frequency lasers. The signal acquisition and processing module is used to receive the output beat frequency signal of the two Y-shaped cavity double-frequency lasers and the difference between the two beat frequencies is calculated and used as the final output signal of an acceleration system. The double Y-shaped cavity double-frequency laser accelerometer measures the acceleration of a carrier by measuring the difference between the beat frequencies of the two double-frequency lasers and has the characteristics of high resolution, big scale factor, high linearity, digital output and the like.
Description
Technical Field
The invention relates to a novel high-precision laser accelerometer, in particular to a novel gas bellows type double-frequency laser accelerometer, belonging to the technical field of laser and precision measurement.
Background
An accelerometer is an important element in an inertial navigation and guidance system, and converts the motion acceleration of a controlled or measured carrier along the direction of an input shaft of the controlled or measured carrier into an electric signal or other signals. The development of accelerometers has gone through decades of history and is of great variety. The development of modern laser technology, optical fiber sensing technology and micro-manufacturing technology provides favorable conditions for the research of optical accelerometers, and the optical accelerometers gradually become hot spots for the research of accelerometers at home and abroad due to the advantages of high sensitivity, strong anti-electromagnetic interference capability and the like.
The laser accelerometer is based on the theory and technology of laser which has been developed for decades, and converts the acceleration along the input axis direction into the output frequency change of the laser, and the acceleration is sensed by measuring the beat frequency. Laser accelerometers are patented more at home and abroad, and can be basically divided into two categories. Firstly, a crystal is arranged in a laser cavity, and the stress generated by acceleration causes the change of the refractive index of the crystal, thereby causing the change of the output frequency. The scheme is more patented, and the precision instruments of the Qinghua university are researched by using the scheme in the national key laboratory (Zhangzhui. orthogonal polarization laser principle [ M ]. Beijing: Qinghua university Press, 2005.224-228). Secondly, the inertia force generated by the acceleration is utilized to cause the deformation of the elastic sensitive element, thereby causing the change of the output frequency. Jospeh P.Ficalora et al propose a scheme for measuring acceleration using the change in the difference frequency between transverse modes caused by the deformation of the highly end-reflecting mirror of the Laser (Jospeh P.Ficalora, Oak Ridge, N.J.high acquisition Laser accumulator: United states Patent, 5456112[ P ]. Oct.10, 1995). Martin et al, Graham j by Litton, propose an L-cavity structure in which acceleration causes deformation of one arm of the Laser to produce a difference frequency of left and right-handed polarized light (Graham j. martin, Canoga Park, calif. non-planar Ring Laser Accelerometer: United States Patent, 4637255[ P ]. jan.20, 1987). Generally speaking, the above solutions have various features, but due to the inherent disadvantages in principle and technology, there is no report about the successful development of high-precision laser accelerometers in the world.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the defects of the traditional laser accelerometer scheme are overcome, and a novel high-precision laser accelerometer system scheme, namely a double-Y-cavity double-frequency laser accelerometer, which has high resolution, large scale factor and good linearity is provided.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the invention is composed of an optical module, a working point selection and control module, a signal acquisition and processing module and the like. The optical module is the core of the whole accelerometer and consists of two symmetrical Y-shaped cavity dual-frequency lasers and a novel gas capsule. The S light and the P light are separated by a polarization beam splitting film to form two non-shared cavities respectively. The gas capsule is divided into two parts by a super-thin film sheet, wherein the two parts are filled with sensing gas (such as nitrogen, carbon dioxide, sulfur hexafluoride and the like) with the same pressure, the two parts are respectively communicated with one of the unshared cavities in the two lasers through the upper and lower vent pipes, and the unshared cavity is called as a sensing gas pipe. The diaphragm is an elastic element sensitive to acceleration. In order to improve the sensitivity of the system, a cylindrical mass block is added in the center of the diaphragm in an optical cement mode. The working point selection and control module is used for selecting and controlling the working point of the accelerometer, and the frequency of the dual-frequency laser is stabilized by adopting a light intensity difference method. The signal acquisition and processing module is used for receiving output beat frequency signals of the two Y-shaped cavity double-frequency lasers, and calculating the difference between the two beat frequencies to be the final output signal of the accelerometer system.
The basic working process of the invention is as follows: when acceleration is input in a direction perpendicular to the ultrathin membrane, the ultrathin membrane generates elastic deformation, the volume of the upper half part of the gas membrane box is increased (or reduced), the volume of the lower half part of the gas membrane box is reduced (or increased), the gas density in the sensing gas tube connected with the upper half part of the membrane box is reduced, the refractive index is correspondingly reduced, and the optical length is reduced, so that the optical length difference of two non-shared cavities is changed, and the output beat frequency of the double-frequency laser, namely the frequency difference of S light and P light, is changed. Similarly, the output beat frequency of the other dual-frequency laser will change inversely.
The working principle of the invention is analyzed in detail as follows:
when the acceleration input in the direction perpendicular to the diaphragm is a, the deformation and stress of the diaphragm are analyzed as shown in fig. 4. The inertial force load generated by the self mass of the diaphragm is q0＝-ρ0at, where ρ0Is the density of the membrane material and t is the thickness of the membrane. Let the density of the cylindrical mass block be rhomDiameter dmHeight tmThe inertial force load of the mass block to the diaphragm is qm＝-ρmatm. The load generated by the pressure of the gas in the upper part and the lower part of the diaphragm on the diaphragm is respectively-p1And p2. When q ism＞＞q0，p1，p2，dmWhen d is the diameter of the diaphragm, the problem can be simplified to the case of concentrated force applied to the center of the flat diaphragm. The concentrated force is the resultant of the forces in FIG. 4
F＝ma+m0a-(p2-p1)πR2 (1)
Wherein m is0Is the mass of the diaphragm, m is the mass of the mass, is the diaphragm radius.
Setting the volume change of the upper and lower parts of the diaphragm box caused by the deformation of the diaphragm as DeltaV, and the pressure change (p) of the upper and lower parts of the diaphragm box according to the gas state equation2-p1) Is composed of
Wherein, DeltaV is the volume change of the gas on the upper (or lower) part of the diaphragm capsule, and V0And p0The volume and pressure of the gas in the upper (or lower) part of the capsule, respectively, without acceleration input.
According to the elastic mechanics knowledge, when the center of the circular plane diaphragm on the fixed edge is subjected to a concentrated force F, the deflection of the position r away from the circle center on the diaphragm is[6，7]
Wherein, <math><mrow><mi>D</mi><mo>=</mo><mfrac><msup><mi>Et</mi><mn>3</mn></msup><mrow><mn>12</mn><mrow><mo>(</mo><mn>1</mn><mo>-</mo><msup><mi>μ</mi><mn>2</mn></msup><mo>)</mo></mrow></mrow></mfrac></mrow></math> the bending rigidity of the quartz diaphragm is shown, mu is the Poisson ratio of the diaphragm material, and E is the Young modulus of the diaphragm material. The geometric volume enclosed by the diaphragm after elastic deformation and the initial plane of the diaphragm is the change of the volume of the diaphragm box caused by acceleration. The change of the volume of the upper half part of the gas diaphragm box caused by the acceleration a is easily deduced from (1) to (3)
Wherein, <math><mrow><mi>η</mi><mo>=</mo><mfrac><mn>5</mn><mrow><mn>64</mn><mi>D</mi></mrow></mfrac><mo>·</mo><mfrac><mrow><msub><mi>p</mi><mn>0</mn></msub><msup><mi>R</mi><mn>6</mn></msup></mrow><msub><mi>V</mi><mn>0</mn></msub></mfrac><mo>.</mo></mrow></math>
neglecting the volume of the vent pipe between the gas film box and the sensing gas pipe, the initial total volume of the gas film box and the sensing gas pipe is
Wherein L is1For the length of the sensing gas tube, phi is the diameter of the sensing gas tube, epsilon1Is the upper half height of the gas capsule. From the expressions (4) and (5), the density change of the sensing gas due to the acceleration a is represented by
From the formula Gladstone-Dale <math><mrow><mfrac><mrow><mi>n</mi><mo>-</mo><mn>1</mn></mrow><mi>ρ</mi></mfrac><mo>=</mo><mi>k</mi></mrow></math> (k is a G-D constant which is a Gradstone-Dell constant), and the change in refractive index of the sensing gas due to the acceleration a can be obtained as
The change in the index of refraction of the sensing gas caused by acceleration is referred to as the first stage of sensing of the present invention, and the gas capsule is also referred to as the "first stage sensing element".
The laser frequency in the Y-cavity dual-frequency laser should satisfy the resonance condition according to the standing wave condition of the laser
The change in the refractive index of the sensing gas causes the resonant frequency to change to
The change of the output beat frequency of the Y-cavity dual-frequency laser caused by the change of the refractive index of the gas is called as second-stage sensitivity of the invention, and the Y-cavity dual-frequency laser is called as a second-stage sensitive element.
The resonant frequency change Deltav caused by the acceleration a is represented by substituting (6) into (7)
Let in the above formula <math><mrow><mi>SF</mi><mo>=</mo><mfrac><mn>5</mn><mn>128</mn></mfrac><mo>·</mo><mfrac><mrow><msub><mi>v</mi><mn>0</mn></msub><msub><mi>L</mi><mn>1</mn></msub></mrow><mrow><msub><mi>n</mi><mn>1</mn></msub><msub><mi>L</mi><mn>1</mn></msub><mo>+</mo><msub><mi>n</mi><mn>0</mn></msub><msub><mi>L</mi><mn>0</mn></msub></mrow></mfrac><mo>·</mo><mfrac><mrow><mi>kρ</mi><msup><mi>R</mi><mn>4</mn></msup><mrow><mo>(</mo><mi>m</mi><mo>+</mo><msub><mi>m</mi><mn>0</mn></msub><mo>)</mo></mrow></mrow><mrow><msub><mi>V</mi><mn>0</mn></msub><mi>D</mi><mrow><mo>(</mo><mn>1</mn><mo>+</mo><mi>η</mi><mo>)</mo></mrow></mrow></mfrac><mo>,</mo></mrow></math> Then formula (11) can be written as
Δv＝SF·a (9)
SF is called the scale factor of the sensitive acceleration of the single-branch Y-type dual-frequency laser.
For two Y-type cavity dual-frequency lasers in an accelerometer, the trend of change of the refractive index of sensing gas caused by acceleration is opposite, and when the acceleration input in the direction vertical to the ultrathin film is a, the beat frequency outputs of the two Y-type cavity dual-frequency lasers are respectively delta v1＝SF1A and Δ v2＝-SF2A, the output signal of the accelerometer is the difference between the output beat frequencies of the upper and lower lasers
Δv＝(SF1+SF2)·a (10)
From equation (10), the magnitude of the acceleration a can be detected by measuring the difference between the output beat frequencies of the upper and lower lasers.
The invention has the beneficial effects that:
the novel gas capsule is used as a first-stage sensitive element of acceleration, the acceleration is firstly converted into the refractive index change of gas in the capsule, and the design has three advantages:
because the system transmits the acceleration signal to the light path of the laser through the refractive index of the gas, and further changes the optical cavity length of the laser without changing the geometric length of the resonant cavity of the laser, compared with other existing schemes, the input of the acceleration in the scheme does not influence the light path structure of the laser, so the optical module structure and the physical performance of the accelerometer are more stable;
because the gas diaphragm capsule is completely separated from the laser, the structure of the gas diaphragm capsule is completely not limited by the laser, the design provides convenience for further optimizing the structure of the elastic sensitive element, and the resolution and other performance indexes of the system can be improved by changing various parameters of the gas diaphragm capsule;
the acceleration signal is transmitted to the accelerometer through the refractive index of gas, and external noise (mainly temperature) is transmitted to the accelerometer through changing the geometric cavity length of the laser, and the external noise has different influence ways on the output frequency of the accelerometer, so that the separation of the signal and the noise becomes possible, and the resolution of the system can be further improved through a digital signal processing method.
And (II) the unique double-Y cavity structure enables SP light to share a gain region and start oscillation at the same time, and utilizes the primary differential of the SP light and the secondary differential of a symmetrical double-Y cavity laser to inhibit noise caused by temperature change to a great extent. The primary differential of the output frequency of the single-branch double-frequency laser basically eliminates the temperature influence of the shared cavity part; and the second differential of the beat frequency output by the two double-frequency lasers mainly inhibits the zero-bias random change caused by the temperature gradient of the unshared cavity part.
Drawings
FIG. 1 is a structural diagram of an optical module of a dual Y-cavity dual-frequency laser accelerometer;
FIG. 2 is a cross-sectional view of a Y-cavity dual-frequency laser;
FIG. 3 is a cross-sectional view of the novel gas capsule;
FIG. 4 is a schematic view of force analysis of an ultrathin membrane in a gas membrane cassette;
FIG. 5 is a structural diagram of a dual-Y cavity dual-frequency laser accelerometer system;
in the figure, 1 is a Y-cavity dual-frequency laser, 2 is a gas capsule, 3, 8 and 9 are high-reflectivity lenses or output lenses, 4 is a cathode, 5 is an anode, 6 is a polarization beam splitting membrane, 7 is an unshared cavity, 10 is an unshared cavity (a sensing gas tube), 11 is a gain region (filled with helium neon gas), 12 is a vent hole on the sensing gas tube, 13 is a vent hole on the gas capsule, 14 is a ultrathin membrane, 15 is a box body of the gas capsule, 16 is a cylindrical mass block, 17 is a signal acquisition and processing module, 18 is a working point selection and control module, 19 is an optical module, and a is an input acceleration direction.
Detailed Description
An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. But should not therefore limit the scope of the invention.
As shown in fig. 5, the dual-Y cavity dual-frequency laser accelerometer is composed of an optical module 19, a working point selection and control module 18, a signal acquisition and processing module 17, and the like. The working point selection and control module 18 is used for selecting and controlling the working point of the accelerometer, and the frequency of the dual-frequency laser is stabilized by adopting a light intensity difference method; the signal acquisition and processing module 17 is used for receiving the output beat frequency signals of the two Y-shaped cavity dual-frequency lasers, and calculating the difference between the two beat frequencies, namely the final output signal of the accelerometer system; the optical module 19 is the core of the entire system. The following mainly describes the structure and the operation mechanism of the optical module 19 in the embodiment of the present invention.
As shown in fig. 1, the optical module 19 is composed of two Y-cavity dual-frequency lasers 1 and a novel gas capsule 2. The two Y-shaped cavity dual-frequency lasers 1 are fixedly connected with the gas film box 2 by adopting optical cement or adhesion. The Y-type cavity dual-frequency laser 1 is communicated with the gas capsule 2 through vent pipes (12, 13).
As shown in fig. 2, the Y-cavity dual-frequency laser is composed of high-reflectivity mirrors or output plates (3, 8, 9), a shared cavity (including a gain region) 11, an unshared cavity (7, 10), and a polarization splitting film 6. High-reflectivity lenses or output sheets (3, 8, 9) are attached to the end faces of the shared cavity (including the gain region) 11 and the unshared cavities (7, 10) in an optical cement manner to form resonant cavities. The common cavity (including the gain region) 11 is filled with helium neon gas as a gain medium. The unshared cavity 10 is provided with a vent 12. The common cavity (including the gain region) 11 and the non-common cavity 7 are integrally designed and processed. And is fixedly connected with the non-common cavity 10 in an optical cement mode. The two surfaces of the polarization beam splitting film 6 are respectively plated with a polarization beam splitting film and an antireflection film. The cavity (including the shared cavity (including the gain region) 11 and the unshared cavity (7, 10)) of the Y-cavity dual-frequency laser can be made of glass ceramics or other ultralow expansion rate materials.
As shown in fig. 3, the gas capsule case 15 is made of microcrystalline glass material, and has a circular bottom surface, and the capsule case is a flat dish. The ultrathin film sheet 14 is made of quartz glass. The center of the ultra-thin quartz diaphragm 14 is fixedly connected with a cylindrical mass block 16 in a light glue or adhesion mode. The ultra-thin quartz diaphragm 14 and the two gas diaphragm boxes 15 are fixedly connected together in a light glue or adhesion mode to form an upper part and a lower part with equal volumes, so that the gas diaphragm box is formed. The gas capsule box body 15 is provided with a vent hole 13. The upper part and the lower part of the gas film box 2 are filled with sensing gas with equal pressure. The sensing gas can be carbon dioxide, nitrogen, sulfur hexafluoride, etc.
The specific working process of the embodiment is as follows:
as shown in fig. 4, when an acceleration a is input in a direction perpendicular to the ultrathin film 14, the ultrathin film 14 is elastically deformed, the volume of the upper half of the gas film box 2 (fig. 3) is increased (or decreased), and the volume of the lower half is decreased (or increased), so that the gas density in the sensing gas tube 10 connected to the upper half of the gas film box 2 is decreased, the refractive index is correspondingly decreased, and the optical length is decreased, thereby causing the change of the optical length difference of the two non-shared cavities (7, 10), so that the output beat frequency of the Y-cavity dual-frequency laser 1 will change, that is, the frequency difference between S light and P light will also change. Similarly, the output beat frequency of the other Y-cavity dual-frequency laser 1 will change inversely. The operating point selection and control module 18 selects the optimum frequency for the operation of the two Y-cavity dual-frequency lasers 1 and stabilizes the frequency by using isocandela. The signal acquisition and processing module 17 receives the output beat frequencies of the two Y-cavity dual-frequency lasers 1, and calculates the difference between their changes to be the system output signal of the dual Y-cavity dual-frequency laser accelerometer.
Claims (12)
1. A double-Y-cavity double-frequency laser accelerometer is characterized in that a novel gas film box is used as a first-stage acceleration sensitive element, input acceleration changes are converted into refractive index changes of sensing gas in the gas film box, the refractive index changes are further converted into beat frequency output of a Y-cavity double-frequency laser, and then beat frequency differential of the two Y-cavity double-frequency lasers is achieved by using a double-Y-cavity structure, and a final output signal of an accelerometer system is obtained.
2. The dual Y-cavity dual-frequency laser accelerometer according to claim 1, wherein the dual Y-cavity dual-frequency laser accelerometer is composed of an optical module 19, a working point selection and control module 18, and a signal acquisition and processing module 17.
3. The dual Y-cavity dual frequency laser accelerometer according to claim 1, wherein the relationship between the input acceleration and the system output signal is
Δv＝SF·a
Wherein SF is SF ═ SF1+SF2，SF1And SF2Are respectively the scale factors of the sensitive acceleration of the single-branch Y-shaped dual-frequency laser, <math><mrow><msub><mi>SF</mi><mi>i</mi></msub><mo>=</mo><mfrac><mn>5</mn><mn>128</mn></mfrac><mo>·</mo><mfrac><mrow><msub><mi>v</mi><mn>0</mn></msub><msub><mi>L</mi><mrow><mn>1</mn><mi>i</mi></mrow></msub></mrow><mrow><msub><mi>n</mi><mn>1</mn></msub><msub><mi>L</mi><mrow><mn>1</mn><mi>i</mi></mrow></msub><mo>+</mo><msub><mi>n</mi><mn>0</mn></msub><msub><mi>L</mi><mn>0</mn></msub></mrow></mfrac><mo>·</mo><mfrac><mrow><mi>kρ</mi><msup><mi>R</mi><mn>4</mn></msup><mrow><mo>(</mo><mi>m</mi><mo>+</mo><msub><mi>m</mi><mn>0</mn></msub><mo>)</mo></mrow></mrow><mrow><mi>D</mi><mo>[</mo><mi>π</mi><msup><mi>R</mi><mn>2</mn></msup><mo>·</mo><msub><mi>ϵ</mi><mrow><mn>1</mn><mi>i</mi></mrow></msub><mo>+</mo><mi>π</mi><msup><mrow><mo>(</mo><mfrac><mi>φ</mi><mn>2</mn></mfrac><mo>)</mo></mrow><mn>2</mn></msup><mo>·</mo><msub><mi>L</mi><mrow><mn>1</mn><mi>i</mi></mrow></msub><mo>]</mo><mrow><mo>(</mo><mn>1</mn><mo>+</mo><msub><mi>η</mi><mi>i</mi></msub><mo>)</mo></mrow></mrow></mfrac><mo>,</mo></mrow></math> wherein <math><mrow><msub><mi>η</mi><mi>i</mi></msub><mo>=</mo><mfrac><mn>5</mn><mrow><mn>64</mn><mi>D</mi></mrow></mfrac><mo>·</mo><mfrac><mrow><msub><mi>p</mi><mn>0</mn></msub><msup><mi>R</mi><mn>6</mn></msup></mrow><mrow><mi>π</mi><msup><mi>R</mi><mn>2</mn></msup><mo>·</mo><msub><mi>ϵ</mi><mrow><mn>1</mn><mi>i</mi></mrow></msub><mo>+</mo><mi>π</mi><msup><mrow><mo>(</mo><mfrac><mi>φ</mi><mn>2</mn></mfrac><mo>)</mo></mrow><mn>2</mn></msup><mo>·</mo><msub><mi>L</mi><mrow><mn>1</mn><mi>i</mi></mrow></msub></mrow></mfrac><mo>,</mo></mrow></math> D is the bending stiffness of the quartz diaphragm, L1iFor the length of the sensing gas tube, phi is the diameter of the sensing gas tube, epsilon1iThe height m of the box body of which the gas film box is respectively communicated with the laser 1 or 20Is the mass of the diaphragm, m is the mass of the mass block, R is the radius of the ultrathin film, p0Rho and n1The pressure, density and refractive index of the sensing gas in the capsule are respectively the input of no acceleration, k is the Grasdon-Del constant of the sensing gas, v0Is the laser frequency, n0To gain the refractive index of the gas, i ═ 1, 2 denotes two Y-mode dual frequency lasers making up the accelerometer.
4. The dual Y-cavity dual-frequency laser accelerometer according to claims 1 and 2, wherein the optical module 19 is composed of two Y-cavity dual-frequency lasers 1 and a novel gas capsule 2.
5. The dual-Y cavity dual-frequency laser accelerometer according to claims 1 and 4, wherein the gas bellows 2 is composed of two bellows cases 15 and a super-thin film 14, and the two bellows cases 15 and the super-thin film 14 are symmetrically and fixedly connected together by optical cement or adhesion.
6. The dual-Y cavity dual-frequency laser accelerometer according to claims 4 and 5, wherein the two capsule boxes 15 of the gas capsule 2 sealed by the ultra-thin film 14 are filled with sensing gas with the same pressure, and the sensing gas comprises nitrogen, carbon dioxide, sulfur hexafluoride and the like.
7. The dual-Y cavity dual-frequency laser accelerometer according to claim 6, wherein the bellows case is a flat dish, the bellows case has vent holes 13, and the bottom surface of the bellows case 15 has a circular shape, a rectangular shape, etc.
8. The dual-Y-cavity dual-frequency laser accelerometer according to claim 3, wherein the center of the ultra-thin film 14 is bonded with a cylindrical mass 16 by means of optical cement, and the surface shape of other parts of the ultra-thin film 14 includes smooth plane, sawtooth shape, trapezoid shape, etc.
9. The dual-Y cavity dual-frequency laser accelerometer according to claims 6 and 7, wherein the material of the bellows box body 15 comprises ultra-low expansion coefficient material such as microcrystalline glass, and the material of the ultra-thin film sheet 14 comprises elastic material such as quartz glass.
10. The dual Y-cavity dual-frequency laser accelerometer according to claims 1, 2 and 3, wherein the Y-cavity dual-frequency laser 1 spatially separates the S-light and the P-light by the polarization splitting film 6 to form two unshared cavities (7, 10), and the two unshared cavities (7, 10) and the shared cavity 11 can be in a "Y" shape or other shapes with a bifurcated structure.
11. The dual Y-cavity dual-frequency laser accelerometer according to claims 1, 2 and 3, wherein the Y-cavity dual-frequency laser 1 utilizes the optical path difference of S-light and P-light in two non-common cavities to generate the frequency difference of the two polarized lights, thereby forming frequency splitting.
12. The dual Y-cavity dual-frequency laser accelerometer according to claim 1, wherein the operating point selection and control module 18 selects an operating point of the Y-cavity dual-frequency laser and stabilizes the frequency using a light intensity difference method.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102507450A (en) * | 2011-11-02 | 2012-06-20 | 中国人民解放军国防科学技术大学 | Method and device for measuring refractive index of transparent medium based on Y-shaped-cavity orthogonal polarization laser |
| CN102506728A (en) * | 2011-11-02 | 2012-06-20 | 中国人民解放军国防科学技术大学 | Method and device for measuring displacement based on Y-type cavity orthogonal polarization laser |
| CN109839514A (en) * | 2019-03-19 | 2019-06-04 | 合肥工业大学 | A kind of high-precision optical accelerometer with from zeroing function |
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| CN102507450A (en) * | 2011-11-02 | 2012-06-20 | 中国人民解放军国防科学技术大学 | Method and device for measuring refractive index of transparent medium based on Y-shaped-cavity orthogonal polarization laser |
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| CN109839514A (en) * | 2019-03-19 | 2019-06-04 | 合肥工业大学 | A kind of high-precision optical accelerometer with from zeroing function |
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