High-precision microgyroscope based on noise compression effect and working method thereof

Abstract

The application discloses a high-precision micro gyroscope based on noise compression effect and a working method thereof, mainly relates to a noise compression light source applied to a micro gyroscope based on a silicon-based photonic crystal microcavity, and can be applied to high-precision inertial navigation, missile guidance and other military fields. The application comprises (1) a noise compression light source generation structure; (2) a micro gyroscope structure based on a silicon-based photonic crystal microcavity; (3) a coupling structure of the noise compression light source and the micro gyroscope based on the silicon-based photonic crystal microcavity; and (4) a micro gyroscope test structure based on the silicon-based photonic crystal microcavity. The application has the advantages that the optical scattering noise and other noise sources of a cavity optical force structure in the micro gyroscope based on the silicon-based photonic crystal microcavity can be reduced, and super-high-precision angular velocity detection can be realized.

Description

Technical Field

[0001] This invention relates to a high-precision micro gyroscope based on noise compression effect, specifically to a high-precision micro gyroscope based on noise compression effect and its working method. Background Technology

[0002] With the development of science and technology, human beings have increasingly higher requirements for measurement accuracy. Quantum precision measurement technology is a research field that utilizes quantum effects and techniques to improve measurement accuracy. When using classical light fields for detection, its accuracy is fundamentally limited by the uncertainty principle and scattering noise. As the number of measurements N increases, the limit of measurement uncertainty decreases proportionally to 1 / N, which is called the standard quantum limit.

[0003] In this field, squeezed light is a commonly used noise compression scheme because its noise characteristics enable precise measurements beyond the standard quantum limit. In quantum optics, coherent states were among the earliest classical light fields studied. Before the advent of squeezed states, the detection accuracy of coherent states was limited by shot noise. The emergence of squeezed states, by redistributing noise power, ensures that, without violating the principles of quantum mechanics, the noise power of one orthogonal component is lower than the shot noise reference, while the noise power of the other component is higher than the shot noise reference. This characteristic allows for measurements using the low-noise orthogonal components of the light field in optical measurement and communication systems, thereby breaking through the shot noise reference and achieving detection sensitivity beyond the quantum noise limit.

[0004] High-precision angular velocity sensors, especially high-precision micro-gyroscopes, currently utilize various technologies such as micromechanical vibratory gyroscopes, piezoelectric vibratory gyroscopes, microfluidic gyroscopes, atomic gyroscopes, and triple-float gyroscopes, which have wide and important applications in biomedicine, industrial production, and scientific research. Traditional triple-float gyroscopes exhibit low angular random walk and zero-bias stability, but their complex structure, large size, and high cost prevent miniaturization for wider applications. Therefore, in the research of micro-angular velocity sensors, silicon micromechanical vibratory gyroscopes fabricated using the Coriolis effect not only reduce size and manufacturing costs but also achieve higher accuracy and stability. Based on this principle, various angular velocity sensor implementation methods, including frame-type, tuning fork-type, and ring-type structures, offer advantages in terms of angular random walk, zero-bias stability, operating bandwidth, and cost.

[0005] In recent years, thanks to the rapid advancements in precision optical micro / nano fabrication technology, cavity optical-mechanical structures have experienced vigorous development. A cavity optical-mechanical structure is a micro / nano cavity structure that, due to optical-mechanical coupling at the micro / nano scale, simultaneously possesses optical and mechanical modes and can exchange energy. The low power consumption and low noise characteristics of cavity optical-mechanical structures enable them to measure physical quantities such as minute displacements, masses, temperatures, accelerations, angular velocities, and gravitational waves with extremely high accuracy. This provides a novel approach for designing and implementing high-precision micro-optical gyroscopes, with the potential to achieve detection resolution approaching the quantum noise limit.

[0006] By using a noise-compressing light source instead of a traditional laser source to excite a silicon-based photonic crystal microcavity microgyroscope, the influence of noise sources such as shot noise can be largely suppressed, thereby further improving the detection accuracy of the silicon-based photonic crystal microcavity microgyroscope. The development of this technology is of great significance for improving measurement accuracy and its application in fields such as navigation and inertial navigation. Summary of the Invention

[0007] This invention addresses the technical challenge of high-precision angular velocity detectors failing to exceed noise limits, and is illustrated here with a high-precision micro-gyroscope based on noise compression. This invention utilizes a noise-compressing light source as the excitation for a silicon-based photonic crystal microcavity micro-gyroscope, further suppressing noise sources such as shot noise introduced by traditional laser sources. By leveraging the characteristics of the noise-compressing light source, the measurement accuracy of the micro-gyroscope can be effectively improved, exceeding the standard quantum noise limit, making it more reliable and accurate in practical applications.

[0008] To achieve the above-mentioned objectives, the technical solution of this invention is as follows:

[0009] A high-precision micro-gyroscope based on noise compression effect is applied to a silicon-based photonic crystal microcavity, including a noise compression light source 1, a silicon-based photonic crystal microcavity micro-gyroscope 2, a coupling structure between the noise compression light source and the silicon-based photonic crystal microcavity micro-gyroscope 3, and a silicon-based photonic crystal microcavity micro-gyroscope testing structure 4.

[0010] The noise compression light source 1 and the silicon-based photonic crystal microcavity-based microgyroscope 2 are connected through the noise compression light source and the silicon-based photonic crystal microcavity-based microgyroscope coupling structure 3; the silicon-based photonic crystal microcavity-based microgyroscope test structure 4 is connected to the noise compression light source and the silicon-based photonic crystal microcavity-based microgyroscope coupling structure 3.

[0011] The noise compression light source 1 is used to: generate compressed light to drive the micro-gyroscope 2 based on a silicon-based photonic crystal microcavity;

[0012] The micro gyroscope 2 based on a silicon-based photonic crystal microcavity is a test chip in the overall test system. It is equipped with a silicon-based photonic crystal, which is used to improve the angular velocity measurement accuracy of the micro gyroscope.

[0013] The coupling structure 3 between the noise compression light source and the micro-gyroscope based on silicon photonic crystal microcavity is used to couple the compressed light generated by the noise compression light source 1 to the photonic crystal microcavity in the micro-gyroscope 2 based on silicon photonic crystal microcavity.

[0014] The micro-gyroscope test structure 4 based on silicon-based photonic crystal microcavity is used to observe the mechanical signals generated by the overall system.

[0015] As a preferred embodiment, the noise compression light source 1 includes a laser source 14, an isolator 15, a polarization beam splitter 16, a 50 / 50 beam splitter A19-1, and a balanced zero-difference detector 22, all of which are centrally aligned along the first optical axis.

[0016] It also includes a frequency doubling cavity 18 aligned with the center along the second optical axis, a dichroic beam splitter A17-1, a dichroic beam splitter B17-2, a 50 / 50 beam splitter B19-2, and an optical parametric amplifier B20.

[0017] The frequency doubling cavity 18 includes a piezoelectric transducer 18-1 arranged in the same optical axis direction, two concave lenses 18-2, and a periodically polarized potassium titanium phosphate crystal 18-3, wherein the two concave lenses 18-2 are located on both sides of the periodically polarized potassium titanium phosphate crystal 18-3.

[0018] The optical parametric amplifier B20 includes a piezoelectric transducer 18-1 arranged along the same optical axis, a concave lens 18-2, and a periodically polarized potassium titanyl phosphate crystal 18-3. The concave lens 18-2 is located between the piezoelectric transducer 18-1 and the periodically polarized potassium titanyl phosphate crystal 18-3. One end face of the periodically polarized potassium titanyl phosphate crystal 18-3 is curved, and the other end face is horizontal. The concave surface of the concave lens 18-2 faces the horizontal end face of the periodically polarized potassium titanyl phosphate crystal 18-3.

[0019] After passing through isolator 15 and polarization beam splitter 16, laser source 14 is split into parallel polarized light and vertical polarized light. The parallel polarized light enters 50 / 50 beam splitter A19-1 and is split into two beams. One beam serves as the local oscillator of balanced homodyne detector 22, and the other beam passes through dichroic beam splitter B17-2 and enters optical parametric amplifier B20 for mixing. The vertical polarized light enters frequency doubling cavity 18 through dichroic beam splitter A17-1 to generate pump light required to drive optical parametric amplifier B20. The pump light passes through dichroic beam splitter A17-1, dichroic beam splitter B17-2, and 50 / 50 beam splitter B19-2 before entering optical parametric amplifier B20 for mixing to generate compressed light 21. The compressed light 21 passes through 50 / 50 beam splitter B19-2 and enters balanced homodyne detector 22 to measure the compression degree.

[0020] As a preferred embodiment, the structure of the silicon-based photonic crystal microcavity microgyroscope 2 comprises three parts: a mass block, a driving frame, and a detection frame.

[0021] The drive frame includes a drive coupling beam and a drive module. The drive coupling beam connects the drive module and the mass block. The drive module excites the mass block to resonate at a certain frequency by applying an external voltage.

[0022] The detection frame includes a detection coupling beam and a detection module. The detection coupling beam connects the detection module and the mass block. The detection module converts the displacement into an electrical signal, and the angular velocity is calculated by the signal processing module.

[0023] As a preferred embodiment, the coupling structure 3 between the noise compression light source and the micro-gyroscope based on a silicon-based photonic crystal microcavity includes a fiber polarization controller 8 and a conical fiber 9. The fiber polarization controller 8 is placed on the fiber of the input compressed light, and the conical fiber 9 is coupled to the silicon-based photonic crystal microcavity.

[0024] The optical fiber 9 features a microconcave structure, which partially contacts the silicon-based photonic crystal microcavity to generate energy coupling. During fabrication, the fiber is first drawn into a cone shape using an optical cone stretching platform, then the microconcave structure is pressed out using a pressing tool, and finally heated with a hydrogen flame or alcohol lamp flame to induce permanent deformation. This design effectively controls optical coupling efficiency and transmission loss, improving system stability and performance. In future integrated designs, on-chip integrated silicon waveguides can be used to achieve cavity coupling.

[0025] As a preferred embodiment, the noise compression light source and the micro-gyroscope coupling structure 3 based on a silicon-based photonic crystal microcavity use an on-chip integrated silicon waveguide.

[0026] As a preferred embodiment, the micro-gyroscope test structure 4 based on silicon-based photonic crystal microcavity includes a photodetector 11, a spectrum analyzer 13, and a data collector 12.

[0027] The photodetector 11 is used to demodulate the optical signal generated by the micro-gyroscope 2 based on silicon-based photonic crystal microcavity excited by the noise-compressed light source and convert it into an electrical signal; the spectrum analyzer performs spectrum analysis on the converted electrical signal.

[0028] The photodetector 11 and the spectrum analyzer 13 are electrically connected; the data collector 12 is electrically connected to the computer and is used to collect data of the mechanical signals generated by the system.

[0029] As a preferred method, the micro gyroscope 2 based on silicon-based photonic crystal microcavity is placed in a vacuum cavity for measurement, so as to make the accuracy measurement of the micro gyroscope 2 based on silicon-based photonic crystal microcavity more accurate.

[0030] As a preferred method, the compressed light is generated by an optical parametric amplifier A7 based on a periodically polarized potassium titanium phosphate crystal.

[0031] Frequency doubling cavity 18 provides the frequency-doubled light required to drive optical parametric amplifier A7;

[0032] Vertically polarized light enters frequency doubling cavity 18 via dichroic beam splitter A17-1, generating pump light required to drive optical parametric amplifier B20. When the frequency doubling light and pump light are in phase mode matching, they pass through optical parametric amplifier B20 based on periodically polarized potassium titanium phosphate crystal to generate compressed light that exceeds the standard quantum noise limit.

[0033] The second objective of this invention is to provide a method for operating the high-precision micro gyroscope, which is as follows:

[0034] Noise compression light source 1 is used to generate compressed light to drive micro-gyroscope 2 based on silicon-based photonic crystal microcavity;

[0035] After passing through isolator 15 and polarization beam splitter 16, laser source 14 is split into parallel polarized light and vertical polarized light. The parallel polarized light enters 50 / 50 beam splitter A19-1 and is split into two beams. One beam serves as the local oscillator of balanced homodyne detector 22, and the other beam passes through dichroic beam splitter B17-2 and enters optical parametric amplifier B20 for mixing. The vertical polarized light enters frequency doubling cavity 18 through dichroic beam splitter A17-1 to generate pump light required to drive optical parametric amplifier B20. The pump light passes through dichroic beam splitter A17-1, dichroic beam splitter B17-2, and 50 / 50 beam splitter B19-2 before entering optical parametric amplifier B20 for mixing, generating compressed light 21. The compressed light 21 passes through 50 / 50 beam splitter B19-2 and enters balanced homodyne detector 22 to measure the compression degree.

[0036] The micro gyroscope 2 based on silicon photonic crystal microcavity is the test chip in the overall test system. The micro gyroscope is equipped with a silicon photonic crystal to improve the angular velocity measurement accuracy of the micro gyroscope.

[0037] The silicon-based photonic crystal microcavity microgyroscope 2 consists of three parts: a mass block, a driving frame, and a detection frame.

[0038] The drive frame includes a drive coupling beam and a drive module. The drive coupling beam connects the drive module and the mass block. The drive module excites the mass block to resonate at a certain frequency by applying an external voltage.

[0039] The detection frame includes a detection coupling beam and a detection module. The detection coupling beam connects the detection module and the mass block. The detection module converts the displacement into an electrical signal, and the angular velocity is calculated by the signal processing module.

[0040] The coupling structure 3 between the noise compression light source 1 and the micro-gyroscope based on silicon photonic crystal microcavity couples the compressed light generated by the noise compression light source 1 with the photonic crystal microcavity in the micro-gyroscope 2 based on silicon photonic crystal microcavity.

[0041] The micro-concave structure of the optical cone fiber 9 comes into contact with the microcavity of the silicon-based photonic crystal to generate energy coupling, thus completing the coupling between the compressed light and the micro-gyroscope.

[0042] Micro-gyroscope test structure based on silicon-based photonic crystal microcavity 4: includes photodetector, spectrum analyzer, and data collector;

[0043] The photodetector 11 is used to demodulate the optical signal generated by the micro-gyroscope 2 based on silicon-based photonic crystal microcavity excited by the noise-compressed light source and convert it into an electrical signal; the spectrum analyzer performs spectrum analysis on the converted electrical signal.

[0044] The photodetector 11 and the spectrum analyzer 13 are electrically connected; the data collector 12 is electrically connected to the computer and is used to collect data of the mechanical signals generated by the system.

[0045] The compressed light is generated by an optical parametric amplifier based on a periodically polarized potassium titanyl phosphate crystal, and a frequency doubling cavity provides the frequency-doubled light required to drive the optical parametric amplifier. The frequency-doubled light has higher optical energy, enabling more efficient and stable output and reducing losses during the testing process. When the frequency-doubled light and pump light are well-matched in phase mode, the optical parametric amplifier based on the periodically polarized potassium titanyl phosphate crystal generates compressed light that exceeds the standard quantum noise limit.

[0046] The beneficial effects of this invention are as follows: using a noise-compressing light source to excite a micro-gyroscope based on a silicon-based photonic crystal microcavity reduces the influence of shot noise, enabling higher precision acceleration detection performance that surpasses the standard quantum noise limit. The detection structure employed is an optical resonant cavity based on a silicon-based photonic crystal, which has the advantages of small size and highly sensitive sensing of minute displacements, thereby improving the detection sensitivity of the micro-gyroscope. Attached Figure Description

[0047] Figure 1 A schematic diagram of a silicon-based photonic crystal microcavity microgyroscope and testing system using a noise-compressed light source as excitation, provided by the present invention;

[0048] Figure 2 A schematic diagram of the noise compression light source generation system provided by the present invention;

[0049] Figure 3 A block diagram illustrating the working principle of a micro-gyroscope based on a silicon-based photonic crystal microcavity provided by this invention;

[0050] Figure 4 The graph shows the variation of the random walk angle of the micro-gyroscope based on silicon-based photonic crystal microcavity as a function of the cavity optical detuning rate, which is provided by the present invention.

[0051] In the figure, 1 is a noise-compressing light source, 2 is a micro-gyroscope based on a silicon-based photonic crystal microcavity, 3 is the coupling structure between the noise-compressing light source and the micro-gyroscope based on a silicon-based photonic crystal microcavity, 4 is the test structure of the micro-gyroscope based on a silicon-based photonic crystal microcavity, 5 is a seed light, 6 is a pump field, 7 is an optical parametric amplifier A, 8 is a fiber polarization controller, 9 is a conical fiber, 10 is a vacuum cavity, 11 is a photodetector, 12 is a data collector, and 13 is a spectrum analyzer. 14 is the laser source, 15 is the isolator, 16 is the polarization beam splitter, 17-1 is the dichroic beam splitter A, 17-2 is the dichroic beam splitter B, 18 is the frequency doubling cavity, 18-1 is the piezoelectric transducer, 18-2 is the concave lens, 18-3 is the periodically polarized potassium titanium phosphate crystal, 19-1 is the 50 / 50 beam splitter A, 19-2 is the 50 / 50 beam splitter B, 20 is the optical parametric amplifier B, 21 is the compressed light, and 22 is the balanced homodyne detector. Detailed Implementation

[0052] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0053] like Figure 1 As shown, this embodiment provides a high-precision micro gyroscope based on noise compression effect, applied to a silicon-based photonic crystal microcavity. It is characterized by including a noise compression light source 1, a micro gyroscope based on a silicon-based photonic crystal microcavity 2, a coupling structure between the noise compression light source and the micro gyroscope based on a silicon-based photonic crystal microcavity 3, and a micro gyroscope testing structure based on a silicon-based photonic crystal microcavity 4.

[0054] The noise compression light source 1 and the silicon-based photonic crystal microcavity-based microgyroscope 2 are connected through the noise compression light source and the silicon-based photonic crystal microcavity-based microgyroscope coupling structure 3; the silicon-based photonic crystal microcavity-based microgyroscope test structure 4 is connected to the noise compression light source and the silicon-based photonic crystal microcavity-based microgyroscope coupling structure 3.

[0055] The noise compression light source 1 is used to: generate compressed light to drive the micro-gyroscope 2 based on a silicon-based photonic crystal microcavity;

[0056] The micro gyroscope 2 based on a silicon-based photonic crystal microcavity is a test chip in the overall test system. It is equipped with a silicon-based photonic crystal, which is used to improve the angular velocity measurement accuracy of the micro gyroscope.

[0057] The coupling structure 3 between the noise compression light source and the micro-gyroscope based on silicon photonic crystal microcavity is used to couple the compressed light generated by the noise compression light source 1 to the photonic crystal microcavity in the micro-gyroscope 2 based on silicon photonic crystal microcavity.

[0058] The micro-gyroscope test structure 4 based on silicon-based photonic crystal microcavity is used to observe the mechanical signals generated by the overall system.

[0059] like Figure 2 As shown, the noise compression light source 1 includes a laser source 14, an isolator 15, a polarization beam splitter 16, a 50 / 50 beam splitter A19-1, and a balanced zero-difference detector 22, all aligned with the center along the first optical axis.

[0060] It also includes a frequency doubling cavity 18 aligned with the center along the second optical axis, a dichroic beam splitter A17-1, a dichroic beam splitter B17-2, a 50 / 50 beam splitter B19-2, and an optical parametric amplifier B20.

[0061] The frequency doubling cavity 18 includes a piezoelectric transducer 18-1 arranged in the same optical axis direction, two concave lenses 18-2, and a periodically polarized potassium titanium phosphate crystal 18-3, wherein the two concave lenses 18-2 are located on both sides of the periodically polarized potassium titanium phosphate crystal 18-3.

[0062] The optical parametric amplifier B20 includes a piezoelectric transducer 18-1 arranged along the same optical axis, a concave lens 18-2, and a periodically polarized potassium titanyl phosphate crystal 18-3. The concave lens 18-2 is located between the piezoelectric transducer 18-1 and the periodically polarized potassium titanyl phosphate crystal 18-3. One end face of the periodically polarized potassium titanyl phosphate crystal 18-3 is curved, and the other end face is horizontal. The concave surface of the concave lens 18-2 faces the horizontal end face of the periodically polarized potassium titanyl phosphate crystal 18-3.

[0063] After passing through isolator 15 and polarization beam splitter 16, laser source 14 is split into parallel polarized light and vertical polarized light. The parallel polarized light enters 50 / 50 beam splitter A19-1 and is split into two beams. One beam serves as the local oscillator of balanced homodyne detector 22, and the other beam passes through dichroic beam splitter B17-2 and enters optical parametric amplifier B20 for mixing. The vertical polarized light enters frequency doubling cavity 18 through dichroic beam splitter A17-1 to generate pump light required to drive optical parametric amplifier B20. The pump light passes through dichroic beam splitter A17-1, dichroic beam splitter B17-2, and 50 / 50 beam splitter B19-2 before entering optical parametric amplifier B20 for mixing to generate compressed light 21. The compressed light 21 passes through 50 / 50 beam splitter B19-2 and enters balanced homodyne detector 22 to measure the compression degree.

[0064] The structure of the silicon-based photonic crystal microcavity microgyroscope 2 consists of three parts: a mass block, a driving frame, and a detection frame.

[0065] The drive frame includes a drive coupling beam and a drive module. The drive coupling beam connects the drive module and the mass block. The drive module excites the mass block to resonate at a certain frequency by applying an external voltage.

[0066] The detection frame includes a detection coupling beam and a detection module. The detection coupling beam connects the detection module and the mass block. The detection module converts the displacement into an electrical signal, and the angular velocity is calculated by the signal processing module.

[0067] The noise compression light source and the micro-gyroscope coupling structure 3 based on silicon photonic crystal microcavity include an optical fiber polarization controller 8 and an optical cone fiber 9. The optical fiber polarization controller 8 is placed on the optical fiber of the input compressed light, and the optical cone fiber 9 is coupled to the silicon photonic crystal microcavity.

[0068] The optical cone fiber 9 has a micro-concave structure, which is in contact with the microcavity of the silicon-based photonic crystal to generate energy coupling. During fabrication, the optical fiber is first pulled out of the optical cone using an optical cone stretching platform, and then the micro-concave structure is pressed out using a pressing tool. It is then heated with a hydrogen flame or an alcohol lamp flame to produce permanent deformation.

[0069] The noise compression light source and the micro-gyroscope coupling structure 3 based on silicon-based photonic crystal microcavity use on-chip integrated silicon waveguides.

[0070] The micro-gyroscope test structure 4 based on silicon-based photonic crystal microcavity includes a photodetector 11, a spectrum analyzer 13, and a data collector 12.

[0071] The photodetector 11 is used to demodulate the optical signal generated by the micro-gyroscope 2 based on silicon-based photonic crystal microcavity excited by the noise-compressed light source and convert it into an electrical signal; the spectrum analyzer performs spectrum analysis on the converted electrical signal.

[0072] The photodetector 11 and the spectrum analyzer 13 are electrically connected; the data collector 12 is electrically connected to the computer and is used to collect data of the mechanical signals generated by the system.

[0073] The micro gyroscope 2 based on silicon photonic crystal microcavity is placed in a vacuum cavity for measurement, so that the accuracy measurement of the micro gyroscope 2 based on silicon photonic crystal microcavity is more accurate.

[0074] The compressed light is generated by an optical parametric amplifier A7 based on a periodically polarized potassium titanium phosphate crystal.

[0075] Frequency doubling cavity 18 provides the frequency-doubled light required to drive optical parametric amplifier A7;

[0076] Vertically polarized light enters frequency doubling cavity 18 via dichroic beam splitter A17-1, generating pump light required to drive optical parametric amplifier B20. When the frequency doubling light and pump light are in phase mode matching, they pass through optical parametric amplifier B20 based on periodically polarized potassium titanium phosphate crystal to generate compressed light that exceeds the standard quantum noise limit.

[0077] This embodiment also provides a method for operating the high-precision micro-gyroscope, which is as follows: a noise-compressing light source 1 is used to generate compressed light to drive a micro-gyroscope 2 based on a silicon-based photonic crystal microcavity; the laser source 14, after passing through an isolator 15 and a polarization beam splitter 16, is split into parallel polarized light and vertical polarized light; wherein, the parallel polarized light enters a 50 / 50 beam splitter A19-1 and is split into two beams, one beam serving as the local oscillation of the balanced zero-difference detector 22, and the other beam passes through a dichroic beam splitter B17-2 and enters an optical parametric amplifier B20 for mixing; the vertical polarized light enters a frequency doubling cavity 18 through a dichroic beam splitter A17-1 to generate... The pump light required to drive the optical parametric amplifier B20 passes through dichroic beam splitters A17-1, B17-2, and B19-2, and then enters the optical parametric amplifier B20 for mixing to generate compressed light 21. Compressed light 21 passes through the B19-2 and enters the balanced homodyne detector 22 to measure the compression degree. The silicon-based photonic crystal microcavity microgyroscope 2 is the test chip in the overall test system. This microgyroscope incorporates a silicon-based photonic crystal to improve the angular velocity measurement accuracy. The silicon-based photonic crystal microcavity microgyroscope 2 consists of three parts: The system comprises a mass block, a driving frame, and a detection frame. The driving frame includes a driving coupling beam and a driving module. The driving coupling beam connects the driving module and the mass block. The driving module excites the mass block with an external voltage to resonate at a certain frequency. The detection frame includes a detection coupling beam and a detection module. The detection coupling beam connects the detection module and the mass block. The detection module converts the displacement into an electrical signal, and the signal processing module calculates the angular velocity. A coupling structure 3 between the noise compression light source 1 and the micro-gyroscope based on a silicon-based photonic crystal microcavity couples the compressed light generated by the noise compression light source 1 with the photonic crystal microcavity in the micro-gyroscope 2 based on a silicon-based photonic crystal microcavity. The micro-concave structure of the optical cone fiber 9 comes into contact with the silicon-based photonic crystal microcavity to generate energy coupling, completing the coupling between the compressed light and the micro-gyroscope; the micro-gyroscope test structure 4 based on the silicon-based photonic crystal microcavity includes a photodetector, a spectrum analyzer, and a data collector; the photodetector 11 is used to demodulate the optical signal generated by the silicon-based photonic crystal microcavity micro-gyroscope 2 excited by the noise-compressed light source and convert it into an electrical signal; the spectrum analyzer performs spectrum analysis on the converted electrical signal; the photodetector 11 and the spectrum analyzer 13 are electrically connected; the data collector 12 is electrically connected to the computer and is used to collect the data of the mechanical signals generated by the system.

[0078] See Figure 3 The working principle of the silicon-based photonic crystal microcavity microgyroscope of the present invention is as follows:

[0079] According to relevant theories of structural mechanics, under electrostatic driving conditions, its motion satisfies the following two equations:

[0080] (1)

[0081] (2)

[0082] in and Let be the equivalent mass when moving in the x and y directions. and The eigenfrequency of the sensitive structure, and This is the resonant quality factor corresponding to the intrinsic frequency. The electrostatic driving force provided for the comb capacitor driver Let be the applied angular velocity. Assume the electrostatic driving force is... , For amplitude, To determine the driving angular frequency, we can obtain the equations of motion for the mass in two directions by simultaneously solving the above equations:

[0083] (3)

[0084] (4)

[0085] According to the basic theory of electromagnetism, the capacitance of a push-pull comb capacitor structure can be approximately expressed as:

[0086] (5)

[0087] In the formula: The number of comb teeth. ε0 is the overlap length of the comb teeth, and ε0 is the dielectric The parallel spacing between the comb teeth, the overall structure is Plane edge The shaft moves. Assume the voltages applied to the two fixed comb teeth satisfy the following expression:

[0088] (6)

[0089] Its electrostatic driving force can then be expressed as:

[0090]

[0091] Based on the fundamental theory of cavity optomechanics, the joint equations for the optical resonance and mechanical oscillation systems in an optomechanical cavity are as follows:

[0092] (8)

[0093] (9)

[0094] in The laser detuning rate, Optomechanical coupling rate, For latency, The coupling rate between the pump light transmission medium and the cavity. This is the damping coefficient of the mechanical oscillator. This is the resonant frequency of the mechanical oscillator during free oscillation. For the effective mass of the mechanical oscillator, This refers to the energy within the optical resonant cavity.

[0095] When considering the additional forces present in the optomechanical cavity chip, equation (9) is rewritten as:

[0096] (10)

[0097] in, Let be the equivalent mass when moving in the y-direction. , , These represent the inertial forces obtained by equivalent calculations of light radiation pressure, thermal bath force, and the angular velocity to be detected, respectively.

[0098] In equation (7), the last term on the right-hand side represents the contribution of the external Coriolis force to the mechanical oscillator system, which generates an additional displacement in the mechanical oscillator. Therefore, the displacement of the mechanical oscillator in the entire optomechanical system can be rewritten as:

[0099] (11)

[0100] in This represents the displacement caused by the laser beam. This refers to the thermal Brownian noise present in the mechanical oscillator. When the mechanical oscillator undergoes mechanical resonance under laser irradiation, its time-varying behavior is sinusoidal, i.e.

[0101] (12)

[0102] Substituting equation (12) into equations (8) and (9), we can obtain the Bessel function solution for the photons in the cavity:

[0103] (13)

[0104] in For a Bessel function of the first kind, , Indicates the laser resonant frequency. This represents the eigenfrequency of the optical cavity resonance. Due to the laser detuning rate... Therefore, the actual resonant frequency of the mechanical oscillator under laser irradiation in the optomechanical cavity can be obtained as:

[0105] (14)

[0106] in This is the resonant frequency of the mechanical oscillator under the action of external force. The photon energy within the cavity. Optomechanical coupling rate The initial laser detuning rate, This represents the equivalent damping coefficient.

[0107] As can be seen from equation (14), when the detuning rate of the input laser, the photon energy in the optomechanical cavity, the optomechanical coupling rate, and other parameters are determined, the actual mechanical resonant frequency of the entire optomechanical system will be determined by the displacement caused by the applied force. Based on this principle, the optomechanical cavity system can detect the mechanical frequency shift and the height of the absorption peak of the power spectral density of the photonic crystal resonator caused by the change in displacement of the detection mass block in the y-direction due to the change in the applied angular velocity. Therefore, the magnitude of the applied angular velocity can be determined by measuring the frequency shift and the height of the absorption peak of the power spectral density.

[0108] refer to Figure 4 Based on the above theoretical analysis, this invention will discuss the impact of noise-compressed light sources and ordinary lasers as excitation sources on shot noise generated by a micro-gyroscope based on a silicon-based photonic crystal microcavity.

[0109] This invention primarily analyzes the performance index of a micro-gyroscope in a cavity photonics system after using a noise-compressed light source as excitation. Angle random walk (ARW) refers to the irregular changes in the angle of an object measured by the gyroscope over a certain period due to random factors, mainly used to characterize the short-term accuracy of the gyroscope. This invention exemplifies a silicon-based photonic crystal microcavity micro-gyroscope, primarily discussing the influence of shot noise, which is equivalent to angle random walk (ARW). SN ) to perform calculations.

[0110] Based on the previous derivation, mechanical sensitivity ( This can be represented as:

[0111] (15)

[0112] Lasers produce Poisson-distributed shot noise, which can be converted into an equivalent angular random walk:

[0113] (16)

[0114] in and These represent the optical power and quantum efficiency of the detector, respectively. This represents the actual loss from the optical cavity to the detector. It is the laser input power. It is the reduced Planck constant.

[0115] Specifically, first, the cavity optical detuning Δ = -κ / 2 and the coupling ratio κ are fixed. e =1.5×10 8 and κ i =0.5×10 8 .like Figure 4 As shown, when the cavity optical detuning is Δ=-κ / 2, the corresponding ARW microgyroscope based on a silicon-based photonic crystal microcavity is excited by a noise-compressed light source. SN1 Curves and ARW under ordinary laser excitation SN2 The curve comparison shows that after using a noise-compressed light source, the random walk of the gyroscope angle is significantly reduced, the optical shot noise is smaller, and it exceeds the standard quantum noise limit.

[0116] Therefore, the micro-gyroscope measurement system based on silicon-based photonic crystal microcavity, which was built through experiments, can reduce noise sources such as optical shot noise and achieve high-precision acceleration detection.

[0117] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A high-precision micro-gyroscope based on noise compression effect, applied to a silicon-based photonic crystal microcavity, characterized in that: The invention includes a noise-compressing light source (1), a micro-gyroscope based on a silicon-based photonic crystal microcavity (2), a coupling structure between the noise-compressing light source and the micro-gyroscope based on a silicon-based photonic crystal microcavity (3), and a micro-gyroscope testing structure based on a silicon-based photonic crystal microcavity (4). The noise compression light source (1) and the micro gyroscope (2) based on silicon photonic crystal microcavity are connected through the noise compression light source and the coupling structure (3) of the micro gyroscope based on silicon photonic crystal microcavity; the micro gyroscope test structure (4) based on silicon photonic crystal microcavity is connected to the noise compression light source and the coupling structure (3) of the micro gyroscope based on silicon photonic crystal microcavity. The noise compression light source (1) is used to generate compressed light to drive a micro gyroscope (2) based on a silicon-based photonic crystal microcavity. The micro gyroscope based on silicon photonic crystal microcavity (2) is a test chip in the overall test system, on which a silicon photonic crystal is provided. The silicon photonic crystal is used to improve the angular velocity measurement accuracy of the micro gyroscope. The noise compression light source and the micro-gyroscope coupling structure (3) based on silicon photonic crystal microcavity are used to couple the compressed light generated by the noise compression light source (1) to the photonic crystal microcavity in the micro-gyroscope (2) based on silicon photonic crystal microcavity. The micro-gyroscope test structure based on silicon-based photonic crystal microcavity (4) is used to: observe the mechanical signals generated by the overall system; The noise compression light source (1) includes a laser source (14) aligned with the center along the first optical axis, an isolator (15), a polarization beam splitter (16), a 50 / 50 beam splitter A (19-1), and a balanced zero-difference detector (22). It also includes a frequency doubling cavity (18) aligned with the center along the second optical axis, a dichroic beam splitter A (17-1), a dichroic beam splitter B (17-2), a 50 / 50 beam splitter B (19-2), and an optical parametric amplifier B (20). The frequency doubling cavity (18) includes piezoelectric transducers (18-1) arranged along the same optical axis, two concave lenses (18-2), and a periodically polarized potassium titanium phosphate crystal (18-3), wherein, Two concave lenses (18-2) are located on either side of the periodically polarized potassium titanium oxyphosphate crystal (18-3); The optical parametric amplifier B (20) includes a piezoelectric transducer (18-1) arranged in the same optical axis direction, a concave lens 18-2 and a periodically polarized potassium titanyl phosphate crystal (18-3), wherein the concave lens (18-2) is located between the piezoelectric transducer (18-1) and the periodically polarized potassium titanyl phosphate crystal (18-3), one end face of the periodically polarized potassium titanyl phosphate crystal (18-3) is curved and the other end face is horizontal, and the concave surface of the concave lens (18-2) faces the horizontal end face of the periodically polarized potassium titanyl phosphate crystal (18-3); After passing through isolator (15) and polarization beam splitter (16), the laser source (14) is divided into parallel polarized light and vertical polarized light. Among them, the parallel polarized light enters the 50 / 50 beam splitter A (19-1) and is split into two beams. One beam is used as the local oscillation of the balanced zero-difference detector (22), and the other beam enters the optical parametric amplifier B (20) through the dichroic beam splitter B (17-2) for mixing. The vertical polarized light enters the optical parametric amplifier B (20) through the dichroic beam splitter A (17-1) and enters the optical parametric amplifier B (20) for mixing. The pump light required to drive the optical parametric amplifier B (20) is generated by the frequency doubling cavity (18). The pump light passes through the dichroic beam splitter A (17-1), the dichroic beam splitter B (17-2), and the 50 / 50 beam splitter B (19-2) and enters the optical parametric amplifier B (20) for mixing to generate compressed light (21). The compressed light (21) passes through the 50 / 50 beam splitter B (19-2) and enters the balanced zero-difference detector (22) to measure the compression degree.

2. A high-precision micro-gyroscope based on noise compression effect as described in claim 1, characterized in that: The structure is based on a silicon-based photonic crystal microcavity microgyroscope (2), which consists of three parts: a mass block, a driving frame, and a detection frame. The drive frame includes a drive coupling beam and a drive module. The drive coupling beam connects the drive module and the mass block. The drive module excites the mass block to resonate at a certain frequency by applying an external voltage. The detection frame includes a detection coupling beam and a detection module. The detection coupling beam connects the detection module and the mass block. The detection module converts the displacement into an electrical signal, and the angular velocity is calculated by the signal processing module.

3. A high-precision micro-gyroscope based on noise compression effect as described in claim 1, characterized in that: The noise compression light source and the micro-gyroscope coupling structure (3) based on silicon photonic crystal microcavity include a fiber polarization controller (8) and a conical fiber (9). The fiber polarization controller (8) is placed on the fiber of input compressed light, and the conical fiber (9) is coupled to the silicon photonic crystal microcavity. The optical cone fiber (9) has a micro-concave structure. The micro-concave structure is in contact with the microcavity of the silicon-based photonic crystal to generate energy coupling. During the preparation, the optical fiber is first pulled out of the optical cone using an optical cone stretching platform, and then the micro-concave structure is pressed out using a pressing tool. The fiber is then heated with a hydrogen flame or an alcohol lamp flame to produce permanent deformation.

4. A high-precision micro-gyroscope based on noise compression effect as described in claim 1, characterized in that: The noise compression light source and the micro-gyroscope coupling structure (3) based on silicon photonic crystal microcavity use on-chip integrated silicon waveguides.

5. A high-precision micro-gyroscope based on noise compression effect as described in claim 1, characterized in that: The micro gyroscope test structure (4) based on silicon-based photonic crystal microcavity includes a photodetector (11), a spectrum analyzer (13), and a data collector (12). The photodetector (11) is used to demodulate the optical signal generated by the micro-gyroscope (2) based on silicon photonic crystal microcavity excited by the noise-compressed light source and convert it into an electrical signal; the spectrum analyzer performs spectrum analysis on the converted electrical signal; The photodetector (11) and the spectrum analyzer (13) are electrically connected; the data collector (12) and the computer are electrically connected to collect data of the mechanical signals generated by the system.

6. A high-precision micro-gyroscope based on noise compression effect as described in claim 1, characterized in that: The silicon-based photonic crystal microcavity micro-gyroscope (2) is placed in a vacuum cavity for measurement, so that the accuracy measurement of the silicon-based photonic crystal microcavity micro-gyroscope (2) is more accurate.

7. A high-precision micro-gyroscope based on noise compression effect as described in claim 1, characterized in that: The compressed light is generated by an optical parametric amplifier A(7) based on a periodically polarized potassium titanium phosphate crystal. The frequency doubling cavity (18) provides the frequency-doubled light required to drive the optical parametric amplifier A (7); Vertically polarized light enters the frequency doubling cavity (18) through the dichroic beam splitter A (17-1), generating the pump light required to drive the optical parametric amplifier B (20). When the frequency doubling light and the pump light are in phase mode matching, they pass through the optical parametric amplifier B (20) based on the periodically polarized potassium oxytitanium phosphate crystal to generate compressed light that exceeds the standard quantum noise limit.

8. The operating method of the high-precision micro gyroscope according to any one of claims 1 to 7, characterized in that: A noise-compressed light source (1) is used to generate compressed light to drive a micro-gyroscope (2) based on a silicon-based photonic crystal microcavity. After passing through isolator (15) and polarization beam splitter (16), the laser source (14) is divided into parallel polarized light and vertical polarized light. Among them, the parallel polarized light enters the 50 / 50 beam splitter A (19-1) and is split into two beams. One beam is used as the local oscillation of the balanced zero-difference detector (22), and the other beam enters the optical parametric amplifier B (20) through the dichroic beam splitter B (17-2) for mixing. The vertical polarized light enters the optical parametric amplifier B (20) through the dichroic beam splitter A (17-1) and enters the optical parametric amplifier B (20) for mixing. The pump light required to drive the optical parametric amplifier B (20) is generated by the frequency doubling cavity (18). The pump light passes through the dichroic beam splitter A (17-1), the dichroic beam splitter B (17-2), and the 50 / 50 beam splitter B (19-2) and enters the optical parametric amplifier B (20) for mixing to generate compressed light (21). The compressed light (21) passes through the 50 / 50 beam splitter B (19-2) and enters the balanced zero-difference detector (22) to measure the degree of compression. The micro gyroscope based on silicon photonic crystal microcavity (2) is the test chip in the overall test system. The micro gyroscope is equipped with silicon photonic crystal to improve the angular velocity measurement accuracy of the micro gyroscope. The micro-gyroscope based on silicon-based photonic crystal microcavity (2) consists of three parts: a mass block, a driving frame, and a detection frame. The drive frame includes a drive coupling beam and a drive module. The drive coupling beam connects the drive module and the mass block. The drive module excites the mass block to resonate at a certain frequency by applying an external voltage. The detection frame includes a detection coupling beam and a detection module. The detection coupling beam connects the detection module and the mass block. The detection module converts the displacement into an electrical signal, and the angular velocity is calculated by the signal processing module. The noise compression light source and the micro-gyroscope coupling structure (3) couples the compressed light generated by the noise compression light source (1) with the photonic crystal microcavity in the micro-gyroscope (2) based on the silicon photonic crystal microcavity. The micro-concave structure of the optical cone fiber (9) comes into partial contact with the microcavity of the silicon-based photonic crystal to generate energy coupling, thus completing the coupling of compressed light with the micro-gyroscope; Micro-gyroscope test structure based on silicon-based photonic crystal microcavity (4): including photodetector, spectrum analyzer, and data collector; The photodetector (11) is used to demodulate the optical signal generated by the micro-gyroscope (2) based on silicon photonic crystal microcavity excited by the noise-compressed light source and convert it into an electrical signal; the spectrum analyzer performs spectrum analysis on the converted electrical signal; The photodetector (11) and the spectrum analyzer (13) are electrically connected; the data collector (12) and the computer are electrically connected to collect data of the mechanical signals generated by the system.

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