A Highly Sensitive Gyroscope Based on Photon Dragging Effect

Abstract

The invention discloses a highly sensitive gyroscope based on the photon drag effect, comprising: a laser modulation module for polarization control and phase modulation of continuous laser and outputting modulated laser; an intermediate module, comprising a resonant cavity and a rotating medium located in the resonant cavity, wherein the resonant cavity is used to strengthen the interaction between the input modulated laser and the rotating medium, wherein the rotating medium is used to generate a photon drag effect through rotation so that the input laser phase generates a left-handed polarization state and a right-handed polarization state, and to generate slow light through a coherent population oscillation effect in the rotating medium, thereby further enhancing the photon drag effect; and a signal processing module, which is used to separate the vertical polarization component in the output laser after passing through the resonant cavity for system detection. The invention is portable, low-cost, small in size and highly sensitive.

Description

Technical Field

[0001] The invention belongs to the field of optical quantum information technology, and in particular relates to a high-sensitivity gyroscope based on the photon drag effect. Background Art

[0002] As an important device for measuring rotation rate, gyroscope plays a core role in the fields of navigation, positioning, inertial systems, etc., and has irreplaceable value in both industrial and military fields. The existing gyroscopes mainly include MEMS gyroscopes, acousto-optic gyroscopes, ring laser gyroscopes, fiber optic gyroscopes, etc. The implementation principles of these gyroscopes are usually based on mechanical principles or optical Sagnac effects. Among them, gyroscopes based on the optical Sagnac effect have higher sensitivity, such as ring laser gyroscopes and fiber optic gyroscopes. However, the large size and high cost of ring laser gyroscopes limit their large-scale development. Due to the influence of thermal, mechanical, acoustic and other factors during the rotation process, fiber optic gyroscopes produce asymmetric excitation in the middle of the optical path, resulting in non-negligible dynamic errors and uncertainty in the signal after interference.

[0003] The existing gyroscopes are often limited by mechanical parts wear, size limitations or environmental and self-interference, and have disadvantages such as poor stability, low sensitivity, large size, high cost, and non-portability. Therefore, there is an urgent need for a portable, low-cost, small-volume, high-sensitivity gyroscope to solve the problems of the current gyroscopes. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a portable, low-cost, small-volume, high-sensitivity gyroscope.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides a high-sensitivity gyroscope based on the photon drag effect, comprising:

[0006] A laser modulation module is used to perform polarization control and phase modulation on continuous laser and output modulated laser;

[0007] The intermediate module includes a resonant cavity and a rotating medium in the resonant cavity, wherein the resonant cavity is used to strengthen the interaction between the modulated laser input into the resonant cavity by the laser modulation module and the rotating medium, and the rotating medium is used to generate a photon dragging effect through rotation so that the modulated laser phase generates a left-handed polarization state and a right-handed polarization state, and to generate slow light through a coherent population oscillation effect in the rotating medium, thereby further enhancing the photon dragging effect;

[0008] The signal processing module is used to separate the vertical polarization component of the output laser after passing through the resonant cavity for system detection.

[0009] Furthermore, the laser modulation module specifically includes a laser, a polarization modulator and a phase modulator. The polarization modulator is specifically a polarization beam splitter, and the phase modulator is specifically an electro-optical modulator.

[0010] Furthermore, the modulated laser is specifically a horizontally polarized continuous laser, whose sideband signal is used as detection light and whose baseband signal is used as pump light.

[0011] Preferably, the resonant cavity is specifically a Fabry-Perot resonant cavity, which is composed of a first cavity mirror and a second cavity mirror arranged opposite to each other, and both the first cavity mirror and the second cavity mirror have a high reflection film.

[0012] Preferably, the rotating medium is any one of ruby, erbium-doped glass rod and praseodymium-doped glass rod.

[0013] Preferably, the signal processing module comprises a polarization beam splitter and a photodetector, wherein the polarization beam splitter is used to separate the vertical polarization component of the output laser, and the photodetector is used to detect the vertical polarization component.

[0014] Preferably, the cavity length of the gyroscope is 20 cm, the reflectivity of the cavity mirror is 99.8%, and the length of the rotating medium is 10 cm.

[0015] Compared with the prior art, the present invention has the following advantages: (1) The present invention is a completely new method for realizing a high-sensitivity gyroscope by utilizing the photon-dragging effect. It is different from the existing mechanical principle and Sagnac effect and has good stability and high precision; (2) The equipment for realizing the photon-dragging effect is simple, low-cost, small in size, and portable, and has better commercial value than the existing high-sensitivity gyroscope; (3) The detection method is simple, and the deflection signal generated by the photon-dragging effect can be detected by using a polarization beam splitter and a photodetector; (4) The rotating medium is easy to obtain and the system is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural diagram of a high-sensitivity gyroscope based on photon drag effect provided by the present invention;

[0017] Figure 2 This is the curve of the vertical component of the gyroscope changing with input power when the rotating medium is ruby ​​and the laser wavelength is 514.5nm;

[0018] Figure 3 This is a graph showing how the sensitivity of the gyroscope changes with input power when the rotating medium is an erbium-doped glass rod and the laser wavelength is 1550nm. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0020] The present invention provides a highly sensitive gyroscope based on the photon drag effect, such as Figure 1 As shown, it includes a laser modulation module I, an intermediate module II and a signal processing module III. The laser modulation module I is used to perform polarization control and phase modulation on the continuous laser and output modulated laser; the intermediate module II includes a resonant cavity and a rotating medium located in the resonant cavity. After the laser enters the resonant cavity, it interacts with the rotating medium. Since the modulated sideband signal is used as the detection light and the baseband signal is used as the pump light, it causes the ground state population number in the rotating medium to oscillate when passing through the rotating medium, resulting in spectral hole burning on the detection spectrum. At this time, the refractive index of the rotating medium changes dramatically, the group refractive index increases rapidly, and the speed of light slows down. At the same time, due to the photon drag effect, the rotation of the rotating medium causes the phase of the laser to deflect, generating left-handed polarized light and right-handed polarized light. The slow light in the rotating medium can enhance the photon drag effect and make the laser phase deflection angle more obvious. The signal processing module III separates the vertical component in the output signal through a polarization beam splitter, and then detects its power by a photodetector.

[0021] In a specific implementation, the laser modulation module 1 specifically includes a laser 1, a polarization modulator 2 and a phase modulator 3 placed in sequence along the light propagation direction. The polarization modulator 2 can specifically be a polarization beam splitter. The phase modulator 3 can specifically be an electro-optical modulator. The laser 1 is used to emit a continuous laser, and the polarization modulator 2 separates the continuous laser into a horizontal polarization component and a vertical polarization component, and propagates the horizontal polarization component to the phase modulator 3, and obtains an ideal modulated laser through phase modulation. The modulated laser then enters the resonant cavity.

[0022] The resonant cavity in the intermediate module II is specifically a Fabry-Perot resonant cavity, which is composed of a first cavity mirror 4 and a second cavity mirror 6 arranged opposite to each other, and the first cavity mirror 4 and the second cavity mirror 6 are both coated with a high-reflection film. The Fabry-Perot resonant cavity can enhance the interaction between the laser and the rotating medium. The rotating medium 5 in the resonant cavity is specifically any one of ruby, erbium-doped glass rod, praseodymium-doped glass rod and other materials. These rotating media can be regarded as a two-level system under a modulated laser of a specific wavelength. The modulated laser interacts with the rotating rotating medium to produce a coherent population oscillation process, resulting in a rapid increase in the group refractive index and the generation of slow light. At the same time, due to the photon dragging effect, the phase of the input light changes between the left-handed and right-handed polarization states, and the slow light generated greatly enhances the photon dragging effect.

[0023] The signal processing module III is specifically a polarization beam splitter, which can separate the vertical polarization component from the light beam with left-handed polarization state and right-handed polarization state output by the resonant cavity. The output vertical polarization component is detected by a photodetector 8, thereby obtaining the sensitivity of the gyroscope.

[0024] The present invention is experimentally verified below.

[0025] Experiment 1: The rotating medium 5 is ruby, and the laser 1 emits a continuous laser with a wavelength of 514.5nm. The vertical component detected by the photodetector 8 changes with the input power as shown in the following figure: Figure 2 As shown, it can be seen that when the rotating medium rotates at a very low speed and the input optical power is in the milliwatt level, the output power of the vertical component can still be detected.

[0026] Experiment 2: The rotating medium 5 is an erbium-doped glass rod, the laser emitted by the laser 1 is a continuous laser with a wavelength of 1550nm, and the length of the erbium-doped glass rod is 10cm. Finally, the sensitivity of the gyroscope detected by the photodetector 8 changes with the input power as follows Figure 3 As shown in the figure, it can be seen that the sensitivity of the gyroscope can reach This is faster than the Earth's rotation speed (7.29×10 -5 rad / s) is several orders of magnitude higher, proving that the gyroscope of the present invention has very high sensitivity.

[0027] The above content describes the implementation principle, system structure and implementation examples of the present invention in combination with the accompanying drawings. However, the present invention is not limited to the above rotating materials and implementation schemes. The specific implementation schemes in the specification only provide specific implementation methods and are not restrictive. Researchers in this field can choose light sources of different wavelengths and rotating media to realize a high-sensitivity gyroscope based on the photon drag effect. There can be various forms of specific implementation without violating its basic principles, all of which fall within the scope of protection of the present invention.

Claims

1. A high-sensitivity gyroscope based on photon drag effect, characterized in that: include: A laser modulation module, used to perform polarization control and phase modulation on a continuous laser and output a modulated laser, wherein the modulated laser is specifically a horizontally polarized continuous laser; The intermediate module includes a resonant cavity and a rotating medium located in the resonant cavity, wherein the resonant cavity is used to strengthen the interaction between the modulated laser input into the resonant cavity by the laser modulation module and the rotating medium, and the rotating medium is used to generate a photon drag effect by rotation so that the modulated laser phase generates a left-handed polarization state and a right-handed polarization state, and when the sideband signal of the modulated laser is used as the detection light and the baseband signal of the modulated laser is used as the pump light, a ground state population oscillation effect is generated in the rotating medium, thereby generating spectral hole burning on the detection spectrum and generating slow light, thereby further enhancing the photon drag effect; The signal processing module is used to separate the vertical polarization component of the output laser after passing through the resonant cavity for system detection.

2. The high-sensitivity gyroscope based on the photon drag effect according to claim 1, characterized in that: The laser modulation module specifically includes a continuous laser, a polarization modulator and a phase modulator.

3. The high-sensitivity gyroscope based on the photon drag effect according to claim 2, characterized in that: The polarization modulator is specifically a polarization beam splitter, and the phase modulator is specifically an electro-optic modulator.

4. The high-sensitivity gyroscope based on the photon drag effect according to claim 1, characterized in that: The resonant cavity is specifically a Fabry-Perot resonant cavity.

5. The high-sensitivity gyroscope based on the photon drag effect according to claim 1, characterized in that: The resonant cavity is composed of a first cavity mirror and a second cavity mirror which are arranged opposite to each other and both have a high reflection film.

6. The high-sensitivity gyroscope based on the photon drag effect according to claim 1, characterized in that: The rotating medium is any one of ruby, erbium-doped glass rod and praseodymium-doped glass rod.

7. The high-sensitivity gyroscope based on the photon drag effect according to claim 1, characterized in that: The signal processing module includes a polarization beam splitter and a photodetector.

8. The high-sensitivity gyroscope based on the photon drag effect according to claim 7, characterized in that: The polarization beam splitter is used to separate the vertical polarization component of the output laser, and the photodetector is used to detect the vertical polarization component.

9. The high-sensitivity gyroscope based on the photon drag effect according to claim 1, characterized in that: The cavity length of the gyroscope is 20 cm, the reflectivity of the cavity mirror is 99.8%, and the length of the rotating medium is 10 cm.

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