Optomechanical gyroscope based on parametric resonance and working method thereof

Abstract

The application discloses an optical-mechanical gyroscope based on parametric resonance and a working method thereof, and belongs to the technical field of optical inertial sensing. The light source module is used for emitting a coherent light field; the mechanical oscillator is used for generating periodic vibration or displacement on a moving platform; the optical resonant cavity is used for converting the displacement of the mechanical oscillator into an optical signal; the stiffness modulation module is used for applying periodic modulation to the equivalent stiffness of the mechanical oscillator; and the signal detection module is used for detecting the optical signal output by the optical resonant cavity and acquiring a detection signal related to angular velocity. The application applies periodic modulation to the equivalent stiffness of the mechanical oscillator, introduces parametric resonance effect, amplifies the mechanical vibration signal induced by the Coriolis force, and thus improves the signal-to-noise ratio and angular velocity resolution of the optical-mechanical gyroscope.

Description

Technical Field

[0001] This invention belongs to the field of optical inertial sensing technology, specifically relating to an optomechanical gyroscope based on parametric resonance and its working method. Background Technology

[0002] As an inertial instrument capable of precisely measuring angular velocity, the gyroscope is an indispensable key device in the fields of aviation, navigation, and aerospace, and its performance directly determines the accuracy of inertial navigation and attitude control systems.

[0003] Traditional optical gyroscopes, such as fiber optic gyroscopes and laser gyroscopes, offer high measurement accuracy, but they typically rely on long optical paths and complex system structures, resulting in large size and high cost, making them difficult to meet the demands of miniaturization and highly integrated applications. Microelectromechanical system (MEMS) gyroscopes offer advantages such as small size, low power consumption, and ease of integration, but their measurement accuracy is usually limited by mechanical noise, structural parameter drift, and insufficient readout signal-to-noise ratio, making them difficult to apply in high-precision scenarios.

[0004] In recent years, optomechanical systems have attracted widespread attention due to their ability to achieve highly sensitive coupling between optical fields and mechanical motion. Optical gyroscopes based on optomechanical effects convert the minute displacements of a mechanical oscillator into optical signals, achieving highly sensitive detection of angular velocity and offering potential advantages in miniaturization and high-precision measurement. However, under weak angular velocity input conditions, the amplitude of the mechanical response induced by the Coriolis force is small, and the output signal is easily overwhelmed by system noise, resulting in a limited signal-to-noise ratio and thus restricting further improvements in angular velocity resolution.

[0005] Parametric resonance is a physical mechanism that significantly amplifies the vibration response of a system by periodically modulating its parameters. It has been studied and applied in the fields of mechanical vibration and microelectromechanical systems. However, current technology lacks a solution to effectively introduce the parametric resonance mechanism into an optomechanical gyroscope and improve its angular velocity detection performance without significantly increasing system complexity.

[0006] Therefore, it is necessary to propose a new optomechanical gyroscope structure and its working method, which enhances the Coriolis force-induced signal by introducing a parametric resonance mechanism, thereby improving the system's signal-to-noise ratio and angular velocity measurement accuracy. Summary of the Invention

[0007] This invention provides an optomechanical gyroscope based on parametric resonance and its working method. By applying periodic modulation to the equivalent stiffness of the mechanical oscillator, a parametric resonance effect is introduced to amplify the mechanical vibration signal induced by the Coriolis force, thereby improving the signal-to-noise ratio and angular velocity resolution of the optomechanical gyroscope.

[0008] This invention is achieved through the following technical solution: An optomechanical gyroscope based on parametric resonance, comprising a light source module, an optical resonant cavity module, a mechanical oscillator, a stiffness modulation module, and a signal detection module. The light source module is used to emit a coherent light field; The mechanical oscillator is used to generate periodic vibration or displacement on the moving platform; The optical resonant cavity is used to convert the displacement of the mechanical oscillator into an optical signal; The stiffness modulation module is used to apply periodic modulation to the equivalent stiffness of the mechanical oscillator; The signal detection module is used to detect the optical signal output by the optical resonant cavity and acquire a detection signal related to angular velocity.

[0009] Furthermore, the mechanical oscillator includes a zero-voltage electrode plate EP0 and a movable reflector M3 fixed on the zero-voltage electrode plate EP0. The zero-voltage electrode plate EP0 is fixed to the moving platform by an elastic suspension structure and generates periodic vibration along the first direction under the drive of the moving platform. When the system rotates around the sensitive axis, the mechanical oscillator is displaced along the second direction perpendicular to the first direction under the action of the Coriolis force.

[0010] Furthermore, the optical resonant cavity includes a fixed reflector M2 and a movable reflector M3, which together constitute the optical resonant cavity. The displacement of the mechanical oscillator in the second direction causes a change in the cavity length, thereby modulating the output optical signal.

[0011] Furthermore, the stiffness modulation module includes an electrode plate group disposed on both sides of the zero-voltage electrode plate EPO. A variable capacitor constrained by the displacement of the mechanical oscillator in the second direction is formed between the electrode plate group and the zero-voltage electrode plate EPO. By applying a periodic modulation voltage to the electrode plate group, the periodic modulation of the equivalent stiffness of the mechanical oscillator is achieved. The stiffness modulation module is configured to periodically change the equivalent stiffness of the mechanical oscillator at a frequency close to twice its natural vibration frequency, thereby stimulating a parametric resonance effect and enhancing the amplitude of the mechanical vibration signal induced by the Coriolis force.

[0012] Furthermore, the signal detection module includes a beam splitter M1, a fixed reflector M4, a photodetector PD1, and a photodetector PD2, which are used to detect the optical signal output from the optical resonant cavity and convert the optical signal into an electrical signal output to obtain a detection signal proportional to the input angular velocity.

[0013] Furthermore, the optical resonant cavity is a Fabry-Perot resonant cavity, a micro-ring resonant cavity, or other optical resonant structures capable of achieving optomechanical coupling.

[0014] A method for operating an optomechanical gyroscope based on parametric resonance is disclosed. The method utilizes an optomechanical gyroscope based on parametric resonance as described in Embodiment 1. The method comprises: driving a mechanical oscillator to generate periodic vibration along a first direction; when the system rotates, the mechanical oscillator is displaced along a second direction under the influence of the Coriolis force; applying periodic modulation to the equivalent stiffness of the mechanical oscillator, causing it to change at a frequency approximately twice the natural frequency of the mechanical oscillator, thereby stimulating a parametric resonance effect; amplifying the mechanical vibration signal induced by the Coriolis force using parametric resonance; forming a cavity field within an optical resonant cavity after a coherent light field emitted from a light source is incident on the optical resonant cavity; the displacement of the mechanical oscillator changes the cavity length of the optical resonant cavity, thereby changing the cavity field and the emitted light signal from the optical resonant cavity; and detecting the light signal through a signal detection module to obtain an output signal proportional to the angular velocity.

[0015] Furthermore, the light source module emits a coherent light field downwards. , With vacuum light field A beam splitter with a 50:50 incidence The light field was then obtained. Incident light from the FP cavity , via total reflection mirror Reflection yields a light field , With FP cavity output light Shot together The light field was then obtained. and , and Separately injected into the photodetector and The result of zero-difference detection can be obtained by subtracting the intensity of the probe light. .

[0016] Furthermore, the electrode plate and Apply voltage respectively and back , Component capacitor and , Component capacitor , There are identical rectangular holes along the left and right edges. exist When moving in the direction, , overlapping area and , overlapping area It will change the same value. , Therefore, it changes at this time. Will be subject to electrostatic force effect, and displacement and voltage Proportional, by setting appropriate Can make , Equivalent to a stiffness The spring.

[0017] Furthermore, the oscillator exist Equivalent stiffness in direction It can be represented as: (1) in, The constant stiffness provided for the U-shaped beam This is the stiffness modulation amplitude. This is the resonant frequency of the mechanical oscillator; The displacement of the mechanical oscillator in the driving direction is The Coriolis force at that time is: (2) in, The equivalent mass of the mechanical oscillator. and The amplitude and initial phase of the mobile platform in the driving direction; Noise force on the oscillator The autocorrelation function is: (3) in, Let be the dissipation coefficient of the oscillator. For Boltzmann constant, The ambient temperature of the oscillator; The cavity optical force on the oscillator is: (4) in, and Let be the resonant frequency and cavity length of the FP cavity field when the oscillator is in the equilibrium position, respectively. To reduce Planck's constant, For FP cavity field operators; The dynamic behavior of the mechanical oscillator in the detection direction can be expressed as: (5) in, This represents the displacement of the mechanical oscillator in the detection direction. The time-coupled mode equations describing the FP cavity field are: (6) in, , Input light frequency, input light field operator , For the input optical field noise operator, its autocorrelation function is: (7) Zero difference detection results The signal-to-noise ratio gain coefficient is: (8) in, To adjust the system signal-to-noise ratio when stiffness modulation is incorporated, The system signal-to-noise ratio without stiffness modulation; when In nearby, When the system enters parametric resonance state, the signal-to-noise ratio of the gyroscope is improved.

[0018] The beneficial effects of this invention are: This invention effectively amplifies the mechanical vibration signal induced by the Coriolis force without significantly increasing system noise by introducing a parametric resonance mechanism, thereby improving the signal-to-noise ratio and angular velocity resolution of the optomechanical gyroscope. This invention does not require a complex multi-cavity structure or a high-precision noise suppression scheme, and the system structure is simple, easy to implement and integrate, making it suitable for high-precision, miniaturized inertial measurement systems. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0020] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0021] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0022] It should also be understood that the terminology used in this application specification is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this application specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0023] The following is in conjunction with the appendix to this application specification. Figure 1 The technical solutions in the embodiments of this application are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0025] Implementation Method 1 This embodiment provides an optomechanical gyroscope based on parametric resonance, which includes a light source module, an optical resonant cavity module, a mechanical oscillator, a stiffness modulation module, and a signal detection module. The light source module is used to emit a coherent light field; The mechanical oscillator is used to generate periodic vibration or displacement on the moving platform; The optical resonant cavity is used to convert the displacement of the mechanical oscillator into an optical signal; The stiffness modulation module is used to apply periodic modulation to the equivalent stiffness of the mechanical oscillator; The signal detection module is used to detect the optical signal output by the optical resonant cavity and acquire a detection signal related to angular velocity.

[0026] Including narrow linewidth light sources and photodetectors and 50:50 beam splitter Total reflection mirror FP laparoscopy and Mobile platform, electrode plate Electrode plate assembly and .

[0027] Zero-voltage electrode plate (Gray) Suspended from the mobile platform (yellow) by a U-shaped beam, total reflection mirror Fixed in superior, There is a set of identical triangular electrodes on each of the left and right sides below the edge. (Blue) and (Red) Fixed on the mobile platform.

[0028] Furthermore, the mechanical oscillator includes a zero-voltage electrode plate EP0 and a movable reflector M3 fixed on the zero-voltage electrode plate EP0. The zero-voltage electrode plate EP0 is fixed to the moving platform by an elastic suspension structure and generates periodic vibration along the first direction under the drive of the moving platform. When the system rotates around the sensitive axis, the mechanical oscillator is displaced along the second direction perpendicular to the first direction under the action of the Coriolis force.

[0029] Furthermore, the optical resonant cavity includes a fixed reflector M2 and a movable reflector M3, which together constitute the optical resonant cavity. The displacement of the mechanical oscillator in the second direction causes a change in the cavity length, thereby modulating the output optical signal.

[0030] Furthermore, the stiffness modulation module includes an electrode plate group disposed on both sides of the zero-voltage electrode plate EPO. A variable capacitor constrained by the displacement of the mechanical oscillator in the second direction is formed between the electrode plate group and the zero-voltage electrode plate EPO. By applying a periodic modulation voltage to the electrode plate group, the periodic modulation of the equivalent stiffness of the mechanical oscillator is achieved. The stiffness modulation module is configured to periodically change the equivalent stiffness of the mechanical oscillator at a frequency close to twice its natural vibration frequency, thereby stimulating a parametric resonance effect and enhancing the amplitude of the mechanical vibration signal induced by the Coriolis force.

[0031] Furthermore, the signal detection module includes a beam splitter M1, a fixed reflector M4, a photodetector PD1, and a photodetector PD2, which are used to detect the optical signal output from the optical resonant cavity and convert the optical signal into an electrical signal output to obtain a detection signal proportional to the input angular velocity.

[0032] The stiffness modulation module includes at least one pair of electrodes, and a variable capacitor is formed between the electrodes and the mechanical oscillator module. The periodic change of the equivalent stiffness of the mechanical oscillator is achieved by applying a periodic modulation voltage to the electrodes.

[0033] The modulation frequency of the periodic modulation voltage is set to twice the natural vibration frequency of the mechanical oscillator or within its adjacent frequency range.

[0034] The mechanical oscillator is a microelectromechanical system structure, including a mass block, an elastic beam, and a support frame.

[0035] Furthermore, the optical resonant cavity is a Fabry-Perot resonant cavity, a micro-ring resonant cavity, or other optical resonant structures capable of achieving optomechanical coupling.

[0036] Implementation Method 2 This embodiment provides a method for operating an optomechanical gyroscope based on parametric resonance. The method uses an optomechanical gyroscope based on parametric resonance as described in Embodiment 1. The method involves: driving a mechanical oscillator to generate periodic vibrations along a first direction; when the system rotates, the mechanical oscillator is displaced along a second direction under the influence of the Coriolis force; periodically modulating the equivalent stiffness of the mechanical oscillator to change its frequency at approximately twice its natural frequency, thereby stimulating a parametric resonance effect; amplifying the mechanical vibration signal induced by the Coriolis force using parametric resonance; forming a cavity field within an optical resonant cavity after a coherent light field emitted from a light source is incident on the optical resonant cavity; the displacement of the mechanical oscillator changes the cavity length of the optical resonant cavity, thereby changing the cavity field and the emitted light signal from the optical resonant cavity; and detecting the light signal through a signal detection module to obtain an output signal proportional to the angular velocity.

[0037] Furthermore, the light source module emits a coherent light field downwards. , With vacuum light field A beam splitter with a 50:50 incidence The light field was then obtained. Incident light from the FP cavity , via total reflection mirror Reflection yields a light field , With FP cavity output light Shot together The light field was then obtained. and , and Separately injected into the photodetector and The result of zero-difference detection can be obtained by subtracting the intensity of the probe light. ; Furthermore, the electrode plate and Apply voltage respectively and back , Component capacitor and , Component capacitor , There are identical rectangular holes along the left and right edges. exist When moving in the direction, , overlapping area and , overlapping area It will change the same value. , Therefore, it changes at this time. Will be subject to electrostatic force effect, and displacement and voltage Proportional, by setting appropriate Can make , Equivalent to a stiffness The spring.

[0038] Furthermore, the oscillator exist Equivalent stiffness in direction It can be represented as: (1) in, The constant stiffness provided for the U-shaped beam This is the stiffness modulation amplitude. This is the resonant frequency of the mechanical oscillator; The displacement of the mechanical oscillator in the driving direction is The Coriolis force at that time is: (2) in, The equivalent mass of the mechanical oscillator. and The amplitude and initial phase of the mobile platform in the driving direction; Noise force on the oscillator The autocorrelation function is: (3) in, Let be the dissipation coefficient of the oscillator. For Boltzmann constant, The ambient temperature of the oscillator; The cavity optical force on the oscillator is: (4) in, and Let be the resonant frequency and cavity length of the FP cavity field when the oscillator is in the equilibrium position, respectively. To reduce Planck's constant, For FP cavity field operators; The dynamic behavior of the mechanical oscillator in the detection direction can be expressed as: (5) in, This represents the displacement of the mechanical oscillator in the detection direction. The time-coupled mode equations describing the FP cavity field are: (6) in, , Input light frequency, input light field operator , For the input optical field noise operator, its autocorrelation function is: (7) Zero difference detection results The signal-to-noise ratio gain coefficient is: (8) in, To adjust the system signal-to-noise ratio when stiffness modulation is incorporated, The system signal-to-noise ratio without stiffness modulation; when In nearby, When the system enters parametric resonance state, the signal-to-noise ratio of the gyroscope is improved.

[0039] Implementation Method 3 This embodiment provides an application method for an optomechanical gyroscope based on parametric resonance as described in Embodiment 1, which is applied to inertial measurement and navigation systems in the modern aviation, maritime, and aerospace fields.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An optomechanical gyroscope based on parametric resonance, characterized in that, The aforementioned optomechanical gyroscope includes a light source module, an optical resonant cavity module, a mechanical oscillator, a stiffness modulation module, and a signal detection module. The light source module is used to emit a coherent light field; The mechanical oscillator is used to generate periodic vibration or displacement on the moving platform; The optical resonant cavity is used to convert the displacement of the mechanical oscillator into an optical signal; The stiffness modulation module is used to apply periodic modulation to the equivalent stiffness of the mechanical oscillator; The signal detection module is used to detect the optical signal output by the optical resonant cavity and acquire a detection signal related to angular velocity.

2. The optomechanical gyroscope according to claim 1, characterized in that, The mechanical oscillator includes a zero-voltage electrode plate EP0 and a movable reflector M3 fixed on the zero-voltage electrode plate EP0. The zero-voltage electrode plate EP0 is fixed to the moving platform by an elastic suspension structure and generates periodic vibration along the first direction under the drive of the moving platform. When the system rotates around the sensitive axis, the mechanical oscillator is displaced along a second direction perpendicular to the first direction under the action of the Coriolis force.

3. The optomechanical gyroscope according to claim 1, characterized in that, The optical resonant cavity includes a fixed reflector M2 and a movable reflector M3, which together constitute the optical resonant cavity. The displacement of the mechanical oscillator in the second direction causes a change in the cavity length, thereby modulating the output optical signal.

4. The optomechanical gyroscope according to claim 1, characterized in that, The stiffness modulation module includes an electrode plate group disposed on both sides of the zero-voltage electrode plate EPO. A variable capacitor constrained by the displacement of the mechanical oscillator in the second direction is formed between the electrode plate group and the zero-voltage electrode plate EPO. By applying a periodic modulation voltage to the electrode plate group, the periodic modulation of the equivalent stiffness of the mechanical oscillator is achieved. The stiffness modulation module is configured to periodically change the equivalent stiffness of the mechanical oscillator at a frequency close to twice its natural vibration frequency, thereby stimulating a parametric resonance effect and enhancing the amplitude of the mechanical vibration signal induced by the Coriolis force.

5. The optomechanical gyroscope according to claim 1, characterized in that, The signal detection module includes a beam splitter M1, a fixed reflector M4, a photodetector PD1, and a photodetector PD2, which are used to detect the optical signal output from the optical resonant cavity and convert the optical signal into an electrical signal output to obtain a detection signal that is proportional to the input angular velocity.

6. The optomechanical gyroscope according to claim 1, characterized in that, The optical resonant cavity is a Fabry-Perot resonant cavity, a micro-ring resonant cavity, or other optical resonant structures capable of achieving optomechanical coupling.

7. A method for operating an optomechanical gyroscope based on parametric resonance, characterized in that, The working method uses an optomechanical gyroscope based on parametric resonance as described in any one of claims 1-6, and the working method is: driving a mechanical oscillator to generate periodic vibration along a first direction; When the system rotates, the mechanical oscillator is displaced along the second direction under the action of the Coriolis force. Periodic modulation is applied to the equivalent stiffness of the mechanical oscillator, causing it to change at a frequency close to twice the natural frequency of the mechanical oscillator, thereby exciting the parametric resonance effect. The mechanical vibration signal induced by the Coriolis force is amplified by the parametric resonance. The coherent light field emitted by the light source is incident on the optical resonant cavity and forms a cavity field therein. The displacement of the mechanical oscillator will change the cavity length of the optical resonant cavity, thereby changing the cavity field and the outgoing light signal of the optical resonant cavity. The light signal is detected by the signal detection module to obtain an output signal proportional to the angular velocity.

8. The working method according to claim 7, characterized in that, The light source module emits a coherent light field downwards. , With vacuum light field A beam splitter with a 50:50 incidence The light field was then obtained. Incident light from the FP cavity , via total reflection mirror Reflection yields a light field , With FP cavity output light Shot together The light field was then obtained. and , and Separately injected into the photodetector and The result of zero-difference detection can be obtained by subtracting the intensity of the probe light. .

9. The working method according to claim 8, characterized in that, electrode plate and Apply voltage respectively and back , Component capacitor and , Component capacitor , There are identical rectangular holes along the left and right edges. exist When moving in the direction, , overlapping area and , overlapping area It will change the same value. , Therefore, it changes at this time. Will be subject to electrostatic force effect, and displacement and voltage Proportional, by setting appropriate Can make , Equivalent to a stiffness The spring.

10. The working method according to claim 9, characterized in that, oscillator exist Equivalent stiffness in direction It can be represented as: (1) in, The constant stiffness provided for the U-shaped beam This is the stiffness modulation amplitude. This is the resonant frequency of the mechanical oscillator; The displacement of the mechanical oscillator in the driving direction is The Coriolis force at that time is: (2) in, The equivalent mass of the mechanical oscillator. and The amplitude and initial phase of the mobile platform in the driving direction; Noise force on the oscillator The autocorrelation function is: (3) in, Let be the dissipation coefficient of the oscillator. For Boltzmann constant, The ambient temperature of the oscillator; The cavity optical force on the oscillator is: (4) in, and Let be the resonant frequency and cavity length of the FP cavity field when the oscillator is in the equilibrium position, respectively. To reduce Planck's constant, For FP cavity field operators; The dynamic behavior of the mechanical oscillator in the detection direction can be expressed as: (5) in, This represents the displacement of the mechanical oscillator in the detection direction. The time-coupled mode equations describing the FP cavity field are as follows: (6) in, , Input light frequency, input light field operator , For the input optical field noise operator, its autocorrelation function is: (7) Zero difference detection results The signal-to-noise ratio gain coefficient is: (8) in, To adjust the system signal-to-noise ratio when stiffness modulation is incorporated. The system signal-to-noise ratio without stiffness modulation; when In nearby, When the system enters parametric resonance state, the signal-to-noise ratio of the gyroscope is improved.

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