Optomechanical resonator with two or more frequency modes

Abstract

This invention is entitled "Optical Mechanical Resonator Having Two or More Frequency Modes". This disclosure relates to apparatus, systems, and techniques for determining acceleration. For example, an accelerometer system includes a resonator and a light-emitting device configured to generate an optical signal based on an error signal. Additionally, the accelerometer includes a modulator configured to: receive the optical signal; generate a modulated optical signal in response to receiving the optical signal; and output the modulated optical signal to the resonator. A light receiver receives a transmitted optical signal from the resonator, wherein the transmitted optical signal indicates the resonant frequency of the resonator. Additionally, the light receiver receives a reflected optical signal from the resonator. The light receiver generates one or more electrical signals based on the transmitted and reflected optical signals. Processing circuitry generates the error signal based on the one or more electrical signals and determines the acceleration.

Description

Technical Field

[0001] This disclosure relates to accelerometers. Background Technology

[0002] An accelerometer functions by detecting the displacement of a test mass under inertial forces. In one example, the accelerometer can detect the displacement of the test mass by measuring the frequency change of a resonator connected between the test mass and a support base. The resonator can be designed to change the frequency proportional to the load applied to the resonator by the test mass under acceleration. The resonator can be electrically coupled to an oscillator circuit or other signal generation circuitry, causing the resonator to oscillate at its resonant frequency. Summary of the Invention

[0003] Generally, this disclosure relates to apparatuses, systems, and techniques for determining the acceleration of one or more devices. For example, the vibrating beam accelerometer (VBA) described herein measures one or more resonant frequencies of a resonator and calculates the acceleration of the VBA based on the corresponding resonant frequencies. In some cases, one or more light-emitting devices can generate optical signals and output these optical signals to a resonator, thereby inducing mechanical vibrations in the resonator. For example, a first light-emitting device can emit a first optical signal to a first end of the resonator, and a second light-emitting device can emit a second optical signal to a second end of the resonator. The resonator allows a first portion of the first optical signal to pass through and reflects a second portion of the first optical signal. Additionally, the resonator allows a first portion of the second optical signal to pass through and reflects a second portion of the second optical signal.

[0004] After a first portion of the first optical signal passes through the resonator, the first portion of the first optical signal may include information indicating a first resonant frequency of the resonator. Additionally, after a first portion of the second optical signal passes through the resonator, the first portion of the second optical signal may include information indicating a second optical signal of the resonator. A photodiode can receive the first portions of the first optical signal and the first portions of the second optical signal, and generate an electrical signal indicating the difference between the first and second resonant frequencies. This frequency difference is related to the acceleration of the VBA.

[0005] In some examples, the accelerometer system includes a resonator and a light-emitting device configured to generate an optical signal based on an error signal. Additionally, the accelerometer includes a modulator configured to: receive the optical signal; generate a modulated optical signal in response to the received optical signal; and output the modulated optical signal to the resonator. The accelerometer system includes a light receiver configured to: receive a transmitted optical signal from the resonator, wherein the transmitted optical signal represents a portion of the modulated optical signal passing through the resonator, and the transmitted optical signal indicates the resonant frequency of the resonator; receive a reflected optical signal from the resonator, wherein the reflected optical signal represents a portion of the modulated optical signal reflected by the resonator; and generate one or more electrical signals based on the transmitted and reflected optical signals. Furthermore, the accelerometer system includes processing circuitry configured to: generate an error signal based on one or more parameters indicated by one or more electrical signals from the reflected optical signal; and determine acceleration based on the resonant frequency indicated by one or more electrical signals.

[0006] In some examples, a method includes: generating an optical signal by a light-emitting device based on an error signal; receiving the optical signal by a modulator; generating a modulated optical signal by the modulator in response to the received optical signal; and outputting the modulated optical signal to a resonator by the modulator. Additionally, the method includes: receiving a transmitted optical signal from the resonator by an optical receiver, wherein the transmitted optical signal represents a portion of the modulated optical signal passing through the resonator, the transmitted optical signal indicating the resonant frequency of the resonator; receiving a reflected optical signal from the resonator by the optical receiver, wherein the reflected optical signal represents a portion of the modulated optical signal reflected by the resonator; and generating one or more electrical signals by the optical receiver based on the transmitted and reflected optical signals. Furthermore, the method includes: generating an error signal by a processing circuit based on one or more parameters of the reflected optical signal indicated by one or more electrical signals; and determining acceleration by the processing circuit based on the resonant frequency indicated by one or more electrical signals.

[0007] In some examples, the resonator includes a mechanical beam extending along a longitudinal axis from a first end to a second end, wherein the mechanical beam includes: a first oscillating surface extending along the longitudinal axis from the first end to the second end; and a second oscillating surface opposite to the first oscillating surface, wherein the second oscillating surface extends along the longitudinal axis from the first end to the second end. The first oscillating surface causes the resonator to vibrate at a first resonant frequency in response to the mechanical beam receiving a first modulated optical signal. The second oscillating surface causes the resonator to vibrate at a second resonant frequency in response to receiving a second modulated optical signal.

[0008] The present invention is intended to provide an overview of the subject matter described herein. It is not intended to provide an exclusive or exhaustive description of the systems, apparatus, and methods detailed in the following drawings and specification. Further details of one or more examples of the present disclosure are set forth in the following drawings and specification. Other features, objects, and advantages will be apparent from the specification and drawings, as well as from the claims. Attached Figure Description

[0009] Figure 1 This is a block diagram illustrating an accelerometer system according to one or more technologies of this disclosure.

[0010] Figure 2 This is a block diagram illustrating a quality block assembly and circuitry according to one or more techniques of this disclosure.

[0011] Figure 3 This is a conceptual diagram illustrating a resonator beam according to one or more techniques of this disclosure.

[0012] Figure 4 It is a diagram showing a first frequency diagram and a second frequency diagram according to one or more techniques according to this disclosure.

[0013] Figure 5 This is a flowchart illustrating an exemplary operation of determining acceleration using an optomechanical resonator beam according to one or more techniques of this disclosure.

[0014] Similar reference characters are used to denote similar elements throughout the specification and drawings. Detailed Implementation

[0015] This disclosure relates to apparatus, systems, and techniques for determining the acceleration of a vibrating beam accelerometer (VBA). For example, this disclosure relates to a VBA having a test mass, a base section, and a resonator beam. The resonator beam can be configured to receive a first optical signal and a second optical signal, which cause the resonator to vibrate at a first resonant frequency and a second resonant frequency, respectively. The corresponding magnitude of the resonant frequency of the resonator beam can indicate the acceleration of the VBA. That is, the first and second resonant frequencies can be changed based on the acceleration of the VBA, and the acceleration of the VBA can be determined based on the first and second resonant frequencies.

[0016] In some examples, a first negative feedback loop controls a first light-emitting device to emit a first optical signal at a first resonant frequency, and a second negative feedback loop controls a second light-emitting device to emit a second optical signal at a second resonant frequency. For example, a resonator allows a first portion of the first optical signal to pass through and a second portion of the first optical signal to be reflected. Additionally, a resonator allows a first portion of the second optical signal to pass through and a second portion of the second optical signal to be reflected. The first portion of the first optical signal may represent a portion of the first optical signal representing the first resonant frequency, and the first portion of the second optical signal may represent a portion of the second resonant frequency representing the second resonant frequency. On the other hand, the reflected portions of the first and second optical signals may respectively represent portions not representing the first and second resonant frequencies. Therefore, the processing circuit can generate a first error signal to adjust the first optical signal emitted by the first light-emitting device to eliminate frequencies other than the first resonant frequency, and the processing circuit can generate a second error signal to adjust the second optical signal emitted by the second light-emitting device to eliminate frequencies other than the second resonant frequency.

[0017] A light receiver (e.g., a photodiode) can receive a first portion of a first optical signal, a second portion of the first optical signal, a first portion of a second optical signal, and a second portion of the second optical signal. The light receiver can generate one or more electrical signals representing the optical signals received by the light receiver, and output the one or more electrical signals to a processing circuit. The processing circuit can generate a first error signal based on the first portion of the first optical signal, and generate a second error signal based on the first portion of the second optical signal. The processing circuit can output the first error signal to a first light-emitting device to adjust the first optical signal to represent a first resonant frequency, and the processing circuit can output the second error signal to a second light-emitting device to adjust the second optical signal to represent a second resonant frequency.

[0018] The processing can determine the acceleration of the VBA based on a first resonant frequency indicated by a first portion of a first optical signal and a second resonant frequency indicated by a first portion of a second optical signal. For example, a relationship may exist between the magnitude of the first resonant frequency and the magnitude of the second resonant frequency of the resonator and the acceleration of the VBA. Therefore, the processing circuit can calculate the acceleration of the VBA based on the difference between the first and second resonant frequencies of the resonator.

[0019] The techniques disclosed herein can provide one or more advantages. For example, the readout signals of some accelerometers may be affected by environmental factors such as temperature. It is possible that a single resonant frequency component of a resonator is affected by the temperature of the environment near the VBA, thus affecting acceleration measured based on a resonant frequency of a certain optical mode. One or more techniques disclosed herein involve determining the acceleration of the VBA based on the difference between two or more resonant frequencies, each of which corresponds to a different optical mode. Environmental factors can affect each of the two or more resonant frequencies by substantially the same amount, thereby eliminating the influence of environmental factors on the measured acceleration. For example, when acceleration is measured based on the difference between a first resonant frequency and a second resonant frequency, a change in temperature can cause both the first and second resonant frequencies to change by the same amount, while the acceleration remains constant. Thus, the difference between the first and second resonant frequencies remains the same, meaning that the measured acceleration remains the same.

[0020] Figure 1 This is a block diagram illustrating an accelerometer system 10 according to one or more technologies of this disclosure. Figure 1 As shown, the accelerometer system 10 includes a processing circuit 12, a resonator beam 20, a test mass block 22, a first light-emitting device 24, a first modulator 25, a first circulator 26, a light receiver 28, a second light-emitting device 32, a second modulator, and a second circulator 34.

[0021] Accelerometer system 10 is configured to determine acceleration based on two or more measured resonant frequencies of a resonator beam 20 mechanically connected to test mass 22. For example, test mass 22 may be able to apply one or both of compressive and tensile forces to resonator beam 20, thereby affecting the two or more resonant frequencies used to determine acceleration. For example, when test mass 22 changes the force applied to resonator beam 20, the first and second resonant frequencies may each change based on the change in the magnitude of the force applied by test mass 22 to resonator beam 20, wherein the change in the magnitude of the force is related to a change in the acceleration of accelerometer system 10. In some examples, accelerometer system 10 may calculate acceleration based on the difference between the first and second resonant frequency modes.

[0022] Processing circuitry 12 may include one or more processors configured to implement functions and / or processing instructions for execution within accelerometer system 10. For example, processing circuitry 12 may be able to process instructions stored in memory. Processing circuitry 12 may include, for example, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry, or a combination of any of the foregoing. Therefore, processing circuitry 12 may include any suitable structure, whether in hardware, software, firmware, or any combination thereof, to perform the functions described herein for processing circuitry 12.

[0023] Memory ( Figure 1 (Not shown) can be configured to store information within the accelerometer system 10 during operation. The memory may include a computer-readable storage medium or a computer-readable storage device. In some examples, the memory includes one or more of short-term memory or long-term memory. The memory may include, for example, random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), magnetic disk, optical disk, flash memory, or electrically programmable memory (EPROM) or electrically erasable programmable memory (EEPROM). In some examples, the memory is used to store program instructions executed by the processing circuitry 12.

[0024] The resonator beam 20 can be represented by the section located between the test mass block 22 and the base ( Figure 1 A mechanical beam (not shown) between the resonator beam 20 and the resonator beam 20. In some cases, the test mass 22 may apply tension or compressive force to the resonator beam 20. In some examples, the resonator beam may be configured to vibrate mechanically according to two or more resonant frequencies. When the test mass 22 applies tension to the resonator beam 20 in response to acceleration in a first direction 58, the tension may “pull” the first end 52 and the second end 54 of the resonator beam 20, and the magnitude of each of the one or more resonant frequencies may change by a predetermined amount corresponding to the magnitude of the tension. Alternatively, when the test mass 22 applies compressive force to the resonator beam 20 in response to acceleration in a second direction 60, the compressive force may “push” the first end 52 and the second end 54 of the resonator beam 20, and the magnitude of each of the two or more resonant frequencies may change by a predetermined amount corresponding to the magnitude of the compressive force.

[0025] Thus, the tension and compressive forces applied to the resonator beam 20 in response to accelerations in the first direction 58 and the second direction 60 may affect the characteristics (e.g., magnitude) of two or more resonant frequencies of the resonator beam 20. Measuring the magnitude and sign (e.g., positive or negative) of each of the two or more resonant frequencies allows the processing circuitry 12 to determine the magnitude and sign of the acceleration of the accelerometer system 10. For example, the processing circuitry 12 may determine the acceleration based on one or more electrical signals generated by the photodetector 28 indicating the difference between the first resonant frequency and the second resonant frequency of the resonator 20.

[0026] In some cases, the first light-emitting device 24 and the second light-emitting device 32 (collectively referred to as "light-emitting devices 24, 32") may include one or more laser devices configured to emit photons. In some examples, the light-emitting devices 24, 32 emit photons with an optical power ranging from 0.1 microwatts (μW) to 10 μW. In some examples, the first light-emitting device 24 is a first semiconductor laser including a first laser diode, and the second light-emitting device 32 is a second semiconductor laser including a second laser diode. The first light-emitting device 24 may generate a first optical signal 44' based on a first error signal received from the processing circuit 12. The second light-emitting device 32 may generate a second optical signal 48' based on a second error signal received from the processing circuit 12.

[0027] The first modulator 25 and the second modulator 33 (collectively referred to as "modulators 25, 33") can modulate optical signals emitted by the first light-emitting device 24 and the second light-emitting device 32, respectively. For example, the first modulator 25 can receive a first optical signal 44' from the first light-emitting device 24, and the first modulator 25 can also receive a first optical signal 44' from the first control unit ( Figure 1 (Not shown) receives a first modulator control signal, which adjusts the way the first modulator 25 modulates the first optical signal. In some cases, the first modulator 25 can transmit the modulated first optical signal 44 to the first circulator 26. Furthermore, the second modulator 33 can receive a second optical signal 48' from the second light-emitting device 32, and the second modulator 33 also receives a signal from the second control unit (…). Figure 1 (Not shown) Receives a second modulator control signal, which adjusts the way the second modulator 33 modulates the second optical signal. In some cases, the second modulator 33 can transmit the modulated second optical signal 48 to the second circulator 34.

[0028] The first circulator 26 and the second circulator 34 (collectively referred to as "circulators 26, 34") can represent optical devices configured to receive optical signals via one or more optical inputs and output optical signals via one or more optical outputs. For example, the first circulator 26 includes first optical inputs 36A–36C (collectively referred to as "first optical input 36") and also includes first optical outputs 38A–38C (collectively referred to as "first optical output 38"). The second circulator 34 includes second optical inputs 40A–40C (collectively referred to as "second optical input 40") and also includes second optical outputs 42A–42C (collectively referred to as "optical output 42").

[0029] The first light-emitting device 24 generates a first optical signal 44' and outputs the first optical signal 44' to the first modulator 25. The first modulator 25 modulates the first optical signal 44' to generate a modulated first optical signal 44. In some examples, the first modulator 25 receives a first modulator control signal that causes the first modulator 25 to generate the modulated first optical signal 44 according to a first optical pattern. The first modulator 25 outputs the modulated first optical signal 44 to a first circulator 26 via an optical input 36A. The first circulator 26 may guide the modulated first optical signal 44 to a first end 52 of the resonator beam 20 via an optical output 38A. The modulated first optical signal 44 may travel through the resonator beam 20 to a position near the center 56 of the resonator beam 20. In some examples, the modulated first optical signal 44 may include a series of optical frequencies. The resonator beam 20 may reflect some of the optical frequencies of the modulated first optical signal 44 and allow some of the optical frequencies of the modulated first optical signal 44 to travel from the first end 52 through the length of the resonator beam 20 to the second end 54.

[0030] The resonator beam 20 can reflect a first portion of the modulated first optical signal 44 and allow a second portion of the modulated first optical signal 44 to pass through the resonator beam 20 from the first end 52 to the second end 54. The second portion of the modulated first optical signal 44 exiting the second end 54 of the resonator beam 20 can represent the "passing" first optical signal 45. The resonator beam 20 can reverse the direction of the first portion of the reflected modulated first optical signal 44, causing the first portion of the modulated first optical signal 44 to exit at the first end 52 of the resonator beam 20. Therefore, the optical signal exiting the first end 52 of the resonator beam 20 can represent the "reflected" first optical signal 46. In some examples, the first portion of the modulated first optical signal 44 includes one or more frequency bands, and the second portion of the modulated first optical signal 44 represents a narrow frequency band indicating the first resonant frequency of the resonator beam 20.

[0031] In some cases, the first illumination mode of the modulated first optical signal 44 can represent a transverse electric (TE) illumination mode. Light propagating according to the TE illumination mode is referred to herein as "TE light." TE light means light that does not induce an electric field in the direction of propagation but induces a magnetic field in the direction of propagation. For example, when the modulated first optical signal 44 propagates from the first end 52 of the resonator beam 20 toward the center 56 of the resonator beam 20, the modulated first optical signal 44 induces a magnetic field relative to the resonator beam 20 in the horizontal direction (e.g., along the direction of the resonator beam 20 from the first end 52 to the second end 54) but does not induce an electric field in the horizontal direction. The TE light of the modulated first optical signal 44 can cause the resonator beam 20 to vibrate mechanically at a first resonant frequency corresponding to the TE illumination mode. The passing first optical signal 45 can then indicate the first resonant frequency of the resonator beam 20. The first circulator 26 can receive the reflected first optical signal 46 via the optical input 36B. The first circulator 26 then outputs the reflected first optical signal 46 to the optical receiver 48 via the optical output 38B.

[0032] The second light-emitting device 32 generates a second optical signal 48' and outputs the second optical signal 48' to the second modulator 33. The second modulator 33 modulates the second optical signal 48' to generate a modulated second optical signal 48. In some examples, the second modulator 33 receives a second modulator control signal that causes the second modulator 33 to generate the modulated second optical signal 48 according to a second optical pattern. The second modulator 33 outputs the modulated second optical signal 48 to a second circulator 34 via an optical input 40A. The second circulator 34 can guide the modulated second optical signal 48 to a second end 54 of the resonator beam 20 via an optical output 42A. The modulated second optical signal 48 can travel through the resonator beam 20 to a position near the center 56 of the resonator beam 20. In some examples, the modulated second optical signal 48 may include a series of optical frequencies. The resonator beam 20 can reflect some of the optical frequencies of the modulated second optical signal 48 and allow some of the optical frequencies of the modulated second optical signal 48 to travel from the second end 54 through the length of the resonator beam 20 to the first end 52.

[0033] The resonator beam 20 can reflect a first portion of the modulated second optical signal 48 and allow a second portion of the modulated second optical signal 48 to pass through the resonator beam 20 from the second end 54 to the first end 52. The second portion of the modulated second optical signal 48 exiting the first end 52 of the resonator beam 20 can represent a "passing" second optical signal 49. The resonator beam 20 can reverse the direction of the first portion of the reflected modulated second optical signal 48, causing the first portion of the modulated second optical signal 48 to exit at the second end 54 of the resonator beam 20. Therefore, the optical signal exiting the second end 54 of the resonator beam 20 can represent a "reflected" second optical signal 50. In some examples, the first portion of the modulated second optical signal 48 includes one or more frequency bands, and the second portion of the modulated second optical signal 48 represents a narrow frequency band indicating the second resonant frequency of the resonator beam 20.

[0034] In some cases, the second illumination mode of the modulated second optical signal 48 can represent a transverse magnetic (TM) illumination mode. Light propagating according to the TM illumination mode is referred to herein as "TM light". TM light indicates light that does not induce a magnetic field in the direction of propagation but induces an electric field in the direction of propagation. For example, when the modulated second optical signal 48 propagates from the second end 54 of the resonator beam 20 toward the center 56 of the resonator beam 20, the modulated second optical signal 48 induces an electric field relative to the resonator beam 20 in the horizontal direction (e.g., along the direction of the resonator beam 20 from the second end 54 to the first end 52) but does not induce a magnetic field in the horizontal direction. The TM light of the modulated second optical signal 48 can cause the resonator beam 20 to vibrate mechanically at a second resonant frequency corresponding to the TM illumination mode. The passing second optical signal 49 can then indicate the second resonant frequency of the resonator beam 20. The second circulator 34 can receive the reflected second optical signal 50 via the optical input 40B. The second circulator 34 then outputs the reflected second optical signal 50 to the optical receiver 48 via the optical output 42B.

[0035] The first circulator 26 may receive the passed second optical signal 49 via optical input 36C and forward the passed second optical signal 49 to the optical receiver 28 via optical output 38C. The second circulator 33 may receive the passed first optical signal 45 via optical input 40C and forward the passed first optical signal 45 to the optical receiver 28 via optical output 42C. Although the modulated first optical signal 44 is described herein as including TE light and the modulated second optical signal 48 is described herein as including TM light, this is not mandatory. In some examples, the modulated first optical signal 44 includes TM light and the modulated second optical signal 48 may include TE light. In some examples, the first optical signal 44 and the second optical signal 48 may include one or more other types of light that cause the resonator beam 20 to vibrate mechanically according to two different modes.

[0036] Generally, the optical receiver 28 may include one or more transistors configured to absorb photons of one or more optical signals and output an electrical signal in response to the absorption of the photons. Thus, the optical receiver 28 can be configured to convert optical signals into electrical signals. The optical receiver 20 receives a first transmitted optical signal 45, a first reflected optical signal 46, a second transmitted optical signal 49, and a second reflected optical signal 50. For example, the optical receiver 28 may include one or more pn junctions that convert photons of one or more optical signals into corresponding electrical signals.

[0037] For example, the optical receiver 28 may generate a first electrical signal component based on the passed first optical signal 45 and a second electrical signal component based on the passed second optical signal 49. The first electrical signal component may retain at least some parameters of the passed first optical signal 45, and the second electrical signal component may retain at least some parameters of the passed second optical signal 49. For example, the first electrical signal component may indicate a first resonant frequency (e.g., TE resonant frequency) indicated by the passed first optical signal 45. The second electrical signal component may indicate a second resonant frequency (e.g., TM resonant frequency) indicated by the passed second optical signal 49.

[0038] One or more frequency and intensity values ​​associated with the transmitted first optical signal 45 and the transmitted second optical signal 49 may be indicated by a first electrical signal component and a second electrical signal component, respectively. For example, in response to receiving a stronger (e.g., higher power) optical signal, the optical receiver 28 may generate a stronger electrical signal (i.e., a larger current value). The optical receiver 28 may include a semiconductor material such as any one or a combination of indium gallium arsenide, silicon, silicon carbide, silicon nitride, gallium nitride, germanium, or lead sulfide.

[0039] In some cases, the difference between the TE resonant frequency and the TM resonant frequency can be related to the acceleration of the accelerometer system 10. For example, a first difference between the TE resonant frequency and the TM resonant frequency can represent a first acceleration, and a second difference between the TE resonant frequency and the TM resonant frequency can represent a second acceleration. When the first difference is greater than the second difference, the first acceleration can be greater than the second acceleration. Alternatively, when the first difference is less than the second difference, the first acceleration can be less than the second acceleration.

[0040] A substantially linear relationship may exist between the difference between the TE resonant frequency and the TM resonant frequency and the acceleration of the accelerometer system 10, but this is not required. For example, the relationship between the difference and the acceleration can be modeled by an equation that is approximately linear but includes one or more quadratic coefficients that introduce slight nonlinear irregularities. In any case, the processing circuit 12 can be configured to apply this relationship to calculate the acceleration of the accelerometer system 10 based on the difference between the TE resonant frequency and the TM resonant frequency indicated by the electrical signal.

[0041] Determining the acceleration of accelerometer system 10 based on the difference between the TE and TM resonant frequencies may be more advantageous than determining acceleration based solely on the measured resonant frequency values. For example, the difference between the TE and TM resonant frequencies is the difference between two frequency values ​​and does not represent a single frequency magnitude. In some examples, environmental factors (such as temperature in the region near accelerometer system 10) can affect both the TE and TM resonant frequencies by the same or similar factors, meaning that the difference between the TE and TM resonant frequencies is essentially unaffected by these environmental factors, which is beneficial.

[0042] Additionally, it may be advantageous if the TE resonant frequency and the TM resonant frequency are different when the acceleration of the accelerometer system 10 is zero. For example, when the difference between the TE resonant frequency and the TM resonant frequency is different, and the acceleration of the accelerometer system 10 is zero, it is easier to determine the difference between the positive acceleration and the negative acceleration of the accelerometer system 10.

[0043] In some examples, processing circuitry 12 is configured to generate a first error signal for output to the first light-emitting device 24. In some examples, processing circuitry 12 generates the first error signal to cause the first light-emitting device 24 to generate a first optical signal 44' that includes one or more frequency components corresponding to the first resonant frequency of resonator 20. Resonator 20 may reflect any portion of the first modulated optical signal 44 outside the narrow band representing the first resonant frequency. These reflected portions are represented by the reflected first optical signal 46. Processing circuitry 12 may generate the first error signal based on one or more parameters of the reflected first optical signal 46 to cause the entire modulated first optical signal 44 to pass through resonator 20. In other words, when the error signal is equal to zero, the magnitude of the reflected first optical signal 46 is zero, and the entire modulated first optical signal 44 passes through resonator 20.

[0044] In some examples, processing circuitry 12 is configured to generate a second error signal for output to the second light-emitting device 32. In some examples, processing circuitry 12 generates the second error signal to cause the second light-emitting device 32 to generate a second optical signal 48' that includes one or more frequency components corresponding to the second resonant frequency of resonator 20. Resonator 20 may reflect any portion of the second modulated optical signal 48 outside the narrow band representing the second resonant frequency. These reflected portions are represented by the reflected second optical signal 50. Processing circuitry 12 may generate the second error signal based on one or more parameters of the reflected second optical signal 50 to cause the entire modulated second optical signal 48 to pass through resonator 20. In other words, when the error signal is equal to zero, the magnitude of the reflected second optical signal 50 is zero, and the entire modulated second optical signal 48 passes through resonator 20.

[0045] In some examples, the accelerometer system 10 may allow acceleration to be measured only along a single test mass displacement axis, thus allowing the accelerometer system 10 to measure acceleration along only one Cartesian axis. In some examples, the test mass displacement axis of the accelerometer system 10 is parallel to a first direction 58 and parallel to a second direction 60. For example, when the test mass 22 is “displaced” closer to the resonator beam 20 along the test mass displacement axis, this may cause tension to be applied to the resonator beam 20, which in turn causes the resonant frequency mode to shift proportionally to the acceleration of the test mass 22. In some cases, to obtain the acceleration of the object relative to all three Cartesian axes, three accelerometer systems are placed on the object such that the test mass displacement axes of the respective accelerometer systems are aligned to form the x-axis, y-axis, and z-axis of Cartesian space. Therefore, readings from each of the three accelerometer systems can be combined to determine the three-dimensional acceleration vector.

[0046] Accelerometer system 10 is configured to measure the acceleration of an object in real time or near real time. Since processing circuitry 12 determines one or more resonant frequencies of resonator beam 20 based on a light signal traveling at the speed of light, processing circuitry 12 can be configured to determine the acceleration of accelerometer system 10 within a very short delay period (e.g., less than one nanosecond (ns)). In other words, processing circuitry 12 can determine the acceleration of accelerometer system 10 at a time very close to the current time (e.g., less than one nanosecond before the current time).

[0047] It may be advantageous to track acceleration in real-time or near real-time to determine the displacement of an object over a period of time. For example, the accelerometer system 10 may be part of an inertial navigation system (INS) used to track the position of an object based at least in part on its acceleration. Alternatively, the accelerometer system 10 may be positioned on or within the object such that the accelerometer system 10 accelerates along with the object. Thus, when the object accelerates, the accelerometer system 10 (including the test mass 22 and the resonator beam 20) accelerates along with the object. Since acceleration over time is the derivative of velocity over time, and velocity over time is the derivative of position over time, in some cases, the processing circuitry 12 may be configured to determine the displacement of the object by performing a double integral of the object's acceleration over a time period. Determining the position of an object using an accelerometer system 10 positioned on the object instead of using a navigation system separate from the object (e.g., Global Positioning System (GPS)) can be referred to as "dead reckoning."

[0048] Figure 2 This is a block diagram illustrating the inspection quality block assembly 14 and circuitry 16 according to one or more techniques of this disclosure. Figure 2 As can be seen, the inspection mass block assembly 14 includes an inspection mass block 22, an intermediate section 62, and a base section 64. The resonator beam 20 may be located on, within, or otherwise contacting the intermediate section 62. Circuit 16 may represent a photoelectric circuit configured to transmit one or more optical signals to the inspection mass block assembly 14. In some examples, circuit 16 includes... Figure 1 The processing circuit 12, the first light-emitting device 24, the first circulator 26, the light receiver 28, the second light-emitting device 32, and the second circulator 34.

[0049] In some examples, the test mass 22 is mechanically connected to the intermediate section 62, and the intermediate section 62 is mechanically connected to the base section 64. The test mass 22, by virtue of its mechanical connection to the intermediate section 62, can apply one or both of compressive and tensile forces to the resonator beam 20. For example, when the test mass assembly 14 accelerates in the first direction 58, the test mass 22 can apply a downward force to the top of the intermediate section 62, causing a decrease in the width 66 of the intermediate section 62 (e.g., compression) and an increase in the length 70 of the intermediate section 62 (e.g., stretching). Because the resonator beam 20 is connected to the intermediate section 62, the decrease in the width 66 of the intermediate section 62 results in a decrease in the width 68 of the resonator beam 20, and the increase in the length 70 of the intermediate section 62 results in an increase in the length 72 of the resonator beam 20. For example, the increase in the length 70 of the intermediate section 62 applies a tension 58' to the resonator beam 20, thereby causing an increase in the length 72 of the resonator beam 20.

[0050] Additionally, in some cases, when the test mass assembly 14 accelerates in the second direction 60, the test mass assembly 22 can apply an upward force to the top of the intermediate segment 62, causing the width 66 of the intermediate segment 62 to increase (e.g., stretch) and the length 70 of the intermediate segment 62 to decrease (e.g., compress). Since the resonator beam 20 is connected to the intermediate segment 62, the increase in the width 66 of the intermediate segment 62 results in an increase in the width 68 of the resonator beam 20, and the decrease in the length 70 of the intermediate segment 62 results in a decrease in the length 72 of the resonator beam 20. For example, the decrease in the length 70 of the intermediate segment 62 applies a compressive force 60' to the resonator beam 20, thereby causing a decrease in the length 72 of the resonator beam 20.

[0051] An increase in the length 72 of the resonator beam 20 caused by tension 58' or a decrease in the length 72 of the resonator beam 20 caused by compressive force 60' may affect one or more resonant frequency modes of the resonator beam 20, which are caused by optical signals delivered to the resonator beam 20 by circuit 16. For example, the first optical signal 44 may include TE light, which causes mechanical vibration of the resonator beam 20 according to the TE resonant frequency mode. Alternatively, the second optical signal 48 may include TM light, which causes mechanical vibration of the resonator beam 20 according to the TM resonant frequency mode. The TE resonant frequency mode may represent a frequency distribution having one or more characteristics including TE resonant frequency values, and the TM resonant frequency mode may represent a frequency distribution having one or more characteristics including TM resonant frequency values.

[0052] In one or more examples where applying tension 58' to resonator beam 20 results in an increase in the length 72 of resonator beam 20, the TE resonant frequency and TM resonant frequency of resonator beam 20 may change in opposite directions. That is, in some cases, in response to the application of tension 58', the TE resonant frequency may increase while the TM resonant frequency decreases, or vice versa. Similarly, in one or more examples where applying compressive force 60' to resonator beam 20 results in a decrease in the length 72 of resonator beam 20, the TE resonant frequency and TM resonant frequency of resonator beam 20 may change in opposite directions. That is, in some cases, in response to the application of compressive force 60', the TE resonant frequency may increase while the TM resonant frequency decreases, or vice versa.

[0053] The difference between the TE resonant frequency value and the TM resonant frequency value can be related to the magnitude of the acceleration of the test mass assembly 14. For example, if a first difference between the first TE resonant frequency value and the first TM resonant frequency value corresponds to a first acceleration value, and a second difference between the second TE resonant frequency value and the second TM resonant frequency value corresponds to a second acceleration value, then when the first difference is greater than the second difference, the first acceleration can be greater than the second acceleration.

[0054] In some examples, the processing circuit (e.g., Figure 1 The processing circuit 12) can determine the sign (e.g., positive or negative) of the acceleration of the test mass assembly 14 based on a comparison of the TE resonant frequency value and the TM resonant frequency value. In some cases, in response to a positive acceleration of the test mass assembly 14 (e.g., acceleration in direction 58), the TE resonant frequency value increases and the TM resonant frequency value decreases, where the TE resonant frequency value and the TM resonant frequency value are almost the same, and the acceleration is zero. Additionally, in some cases, in response to a negative acceleration of the test mass assembly 14 (e.g., acceleration in direction 60), the TE resonant frequency value may decrease and the TM resonant frequency value may increase.

[0055] In at least some of these cases, processing circuit 12 may determine that the acceleration of the test mass assembly 14 is positive in response to determining that the TE resonant frequency value is greater than the TM resonant frequency value. For the same reason, processing circuit 12 may determine that the acceleration of the test mass assembly 14 is negative in response to determining that the TE resonant frequency value is less than the TM resonant frequency value.

[0056] To fabricate the test mass block assembly 14, it may be advantageous to deposit a first thickness of low-refractive-index dielectric material on a wafer of material, and a second thickness of high-refractive-index material on the wafer. The waveguide can be fabricated using photolithography and etching techniques, and the high-refractive-index material can be used to create the linear resonator beam 20. Subsequently, the waveguide and resonator beam 20 can be clad with a second layer of low-refractive-index dielectric material. A second conventional photolithography and etching process can release the test mass block 22 and the anchor (e.g., base segment 64) from the substrate. In some examples, the test mass block assembly 14 may include conventional fabrication of a microheater above the resonator beam 20 to stabilize the accelerometer relative to temperature.

[0057] Figure 3 This is a conceptual diagram illustrating a resonator beam 100 according to one or more techniques of this disclosure. In some examples, the resonator beam 100 is... Figure 1 and Figure 2 Example of resonator beam 20. (e.g.) Figure 3 As shown, the resonator beam 100 includes a first oscillating edge 102 with a peak 104 and a second oscillating edge 112 with a valley 114. The resonator beam 100 may extend along a longitudinal axis 124 from a first end 132 to a second end 134. In some examples, the resonator beam 100 may be located at the first end 132 from a first circulator (e.g., Figure 1 The first circulator 26) receives one or more optical signals, and the resonator beam 100 can receive signals from the second circulator (e.g., at the second end 134) at the second end 134. Figure 1 The second circulator 34) receives one or more optical signals.

[0058] In some examples, one or more sine functions may represent each of the first oscillation edge 102 and the second oscillation edge 112 (collectively referred to as "oscillation edges 102, 112"). Thus, each oscillation edge in oscillation edges 102, 112 may resemble an oscillation pattern. Additionally, in some examples, one or more other functions (e.g., square functions, trigonometric functions, exponential functions, linear functions, polynomial functions, quadratic functions, or any combination thereof) may represent each oscillation edge in oscillation edges 102, 112. These one or more functions may be continuous (e.g., analog) or discrete (e.g., digital) in nature.

[0059] In some examples, the resonator beam 20 may act as a reflecting waveguide, allowing optical signals in one or more frequency bands to propagate through the resonator beam 20 and allowing optical signals in one or more other frequency bands to be "reflected". Oscillating edges 102, 112 may define the optical frequency bands reflected by the resonator beam 20 and the frequency bands that the resonator beam 20 is allowed to pass through. For example, a first oscillating edge 102 may cause the resonator beam 100 to be associated with a first spatial frequency, and a second oscillating edge 112 may cause the resonator beam 100 to be associated with a second spatial frequency, wherein the first spatial frequency and the second spatial frequency represent a first resonant frequency and a second resonant frequency, respectively. In some examples, the first resonant frequency may represent the resonant frequency of the resonator beam 100 caused by a first optical mode (e.g., a TE optical mode), and the second resonant frequency may represent the resonant frequency of the resonator beam 100 caused by a second optical mode (e.g., a TM optical mode).

[0060] In some examples, a pi phase shift may exist relative to the longitudinal axis 124 between the oscillation patterns of the first oscillation edge 102 and the second oscillation edge 112. For example, the peak 104 of the first oscillation edge 102 may be located at the same position 126 along the longitudinal axis 124 as the valley 114 of the second oscillation edge 112. In some cases, each peak of the first oscillation edge 102 may be aligned along the longitudinal axis 124 with a corresponding valley of the second oscillation edge 112. Because the resonator beam 100 includes this pi phase shift, the resonator beam 100 allows a first frequency band of the first modulated optical signal to propagate along the length of the resonator beam 100 from the first end 132 to the second end 134, and allows a second frequency band of the second modulated optical signal to propagate along the length of the resonator beam 100 from the second end 134 to the second end 132. The resonator beam 20 may reflect frequencies of the first modulated optical signal outside the first frequency band from the first end 132 and reflect frequencies of the second modulated optical signal outside the second frequency band from the second end 134.

[0061] The portion of the first modulated optical signal passing through the resonator beam 20 indicates the first resonant frequency, and the portion of the second modulated optical signal passing through the resonator beam 20 indicates the second resonant frequency. Therefore, the first and second resonant frequencies can be identified based on the frequencies present in the respective passing modulated optical signals.

[0062] In some examples, the compressive or tensile force applied to the ends 132, 134 of the resonator beam 100 may affect the first and second resonant frequencies of the resonator beam 100. The mass block assembly (e.g., Figure 2The test mass assembly 14) can apply these corresponding compressive or tensile forces in response to the acceleration of the test mass assembly. In some cases, the magnitude of the difference between the first and second resonant frequencies caused by the forces applied to the ends 132, 134 indicates the magnitude of the acceleration of the test mass assembly.

[0063] The width 122 of the resonator beam 100 may range from 200 nanometers (nm) to 700 nm (e.g., 500 nm), but this is not required. The width 122 of the resonator beam 100 may include any width or width range. In some examples, the length 123 of the resonator beam 100 may range from 1 millimeter (mm) to 5 mm, but this is not required. The length 123 of the resonator beam 100 may include any length or length range.

[0064] The resonator beam 100 is not intended to be limited to Figure 3 The diagram shows the oscillation pattern of the first oscillation edge 102 and the oscillation pattern of the second oscillation edge 112. In some cases, the first oscillation edge 102 may include a pattern greater than that of the second oscillation edge 112. Figure 3 More cycles or more than shown Figure 3 The number of periods is less than that shown. In addition, or alternatively, in some cases, the second oscillation edge 112 may include a shorter period than... Figure 3 More cycles or more than shown Figure 3 The number of cycles is less.

[0065] Figure 4 This is a diagram illustrating a first frequency diagram 142 and a second frequency diagram 144 according to one or more techniques of this disclosure. Figure 4 As can be seen, the first frequency diagram 142 includes a first peak frequency 146, and the second frequency diagram 144 includes a second peak frequency 148. The first peak frequency 146 and the second peak frequency 148 are separated by a frequency difference of 150.

[0066] In some examples, the first frequency profile 142 includes one or more frequency components of a modulated first optical signal 44 delivered to a first end 52 of the resonator beam 20. The first frequency profile 142 may represent the frequency distribution propagating through the resonator beam 20 from the first end 52 to the second end 54. Since the optical receiver 28 receives a passing first optical signal 45 (which includes frequency components passing through the resonator beam 20), the first frequency profile 142 may represent one or more frequency components present in the passing first optical signal 45. In some examples, the first peak frequency 146 may represent the first resonant frequency at which the resonator beam 20 mechanically vibrates.

[0067] In some examples, the second frequency profile 144 includes one or more frequency components of the modulated second optical signal 48 delivered to the second end 54 of the resonator beam 20. The second frequency profile 144 may represent the frequency distribution propagating through the resonator beam 20 from the second end 54 to the first end 52. Since the optical receiver 28 receives the passing second optical signal 49 (which includes the frequency components transmitted by the resonator beam 20), the second frequency profile 144 may represent one or more frequency components present in the passing second optical signal 49. In some examples, the second peak frequency 148 represents the second resonant frequency at which the resonator beam 20 mechanically vibrates.

[0068] Figure 1 The processing circuit 12 can be configured to determine the acceleration of the accelerometer system 10 based on a frequency difference 150, which represents the difference between a first peak frequency 146 and a second peak frequency 148. In some examples, there may be a linear or near-linear relationship between the magnitude of the acceleration of the accelerometer system 10 and the magnitude of the difference between the first peak frequency 146 and the second peak frequency 148. For example, if the acceleration increases, the frequency difference 150 may also increase by a similar proportion, and if the acceleration decreases, the frequency difference 150 may also decrease.

[0069] In some examples, the first frequency diagram 142 may represent one or more frequencies of TE light, and the second frequency diagram 144 may represent one or more frequencies of TM light, but this is not required. In some examples, the first frequency diagram 142 and the second frequency diagram 144 may be associated with other types of light. The first resonant frequency may represent the frequency at which the resonator beam 20 vibrates according to the TE resonant frequency mode, and the second resonant frequency may represent the frequency at which the resonator beam 20 vibrates according to the TM resonant frequency mode.

[0070] Figure 5 This is a flowchart illustrating an exemplary operation of determining acceleration using an optomechanical resonator beam according to one or more techniques of this disclosure. Figure 5 Compared to Figures 1 to 4 The accelerometer system 10, the test mass block assembly 14, the circuit 16, and the resonator beam 100 are used to describe this. However, Figure 5 The technology can be performed by different components of the accelerometer system 10, the test mass block assembly 14, the circuit 16, and the resonator beam 100, or by additional or alternative devices.

[0071] In some examples, processing circuitry 12 may be configured to determine the acceleration of accelerometer system 10. In some examples, accelerometer system 10 may include a resonator beam 20 configured to mechanically vibrate according to a first resonant frequency and a second resonant frequency. For example, resonator beam 20 may represent an optomechanical resonator beam configured to act as an optical waveguide for two or more types of light (e.g., TE light and TM light). Processing circuitry 12 may determine the acceleration based on the difference between the first and second resonant frequencies.

[0072] The first light-emitting device 24 can transmit a first optical signal 44' to a first modulator 25 (502). In some examples, the first modulator 25 can generate a modulated first optical signal 44 to include TE light in order to induce mechanical vibration in the resonator beam 20 according to the TE resonant frequency mode. The first modulator 25 can output the modulated first optical signal 44 to the resonator 20 (504) via a first circulator 26. In other words, the first circulator 26 guides the modulated first optical signal 44 to a first end 52 of the resonator beam 20 via one or more optical fibers. A portion of the modulated first optical signal 44 can travel through the resonator 20 from the first end 52 to a second end 54. This portion of the modulated first optical signal 44 can include a frequency band corresponding to the resonant frequency of the resonator 20. The optical receiver 28 can receive the passed first optical signal 45 (506) from the resonator beam 20 via a second circulator 34. In some examples, the first optical signal 45 may include one or more frequency components of the modulated first optical signal 44 that pass through the resonator beam 20, the one or more frequency components corresponding to the resonant frequency.

[0073] In some examples, processing circuitry 12 may generate an error signal. This error signal may reflect any detectable difference between the modulated first optical signal 44 and the passed first optical signal 45. For example, the first light-emitting device 24 may emit a first optical signal 44' to include a frequency component representing a first resonant frequency of resonator 20. Any frequency component of the first optical signal 44' may be reflected by resonator beam 20. Optical receiver 28 may receive the reflected first optical signal 46, and processing circuitry 12 may generate an error signal based on the reflected first optical signal 46. Processing circuitry 12 outputs the error signal to the first light-emitting device 24 (508) to control the first light-emitting device 24 to generate the first optical signal 44' such that the first optical signal 44' does not include frequencies other than the first resonant frequency.

[0074] In response to receiving the first transmitted optical signal 45, the optical receiver 28 generates an electrical signal (510) based on the first resonant frequency of the resonator beam 20, which is indicated by the first transmitted optical signal 45 received by the optical receiver 28. The optical receiver 28 outputs the electrical signal to the processing circuit 12. The processing circuit 12 can determine the acceleration (512) of the accelerometer system 10 based on the electrical signal.

[0075] In some examples, the accelerometer system 10 includes a second feedback loop that delivers another optical signal to the optical receiver 28, which indicates a second resonant frequency of the resonator beam 20. The processing circuitry 12 can determine the acceleration based on the difference between the first and second resonant frequencies.

[0076] In one or more examples, the accelerometer described herein may implement the functions using hardware, software, firmware, or any combination thereof. Those functions implemented in software may be stored as one or more instructions or code on or transmitted via a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may include a computer-readable storage medium corresponding to a tangible medium such as a data storage medium, or a communication medium that includes, for example, any medium facilitating the transfer of a computer program from one place to another according to a communication protocol. Thus, a computer-readable medium may generally correspond to: (1) a non-transitory tangible computer-readable storage medium, or (2) a communication medium such as a signal or carrier wave. The data storage medium may be any available medium accessible by one or more computers or one or more processors to retrieve instructions, code, and / or data structures for implementing the techniques described herein.

[0077] Instructions may be executed by or communicatively coupled to one or more processors within the accelerometer. These processors may, for example, include one or more DSPs, general-purpose microprocessors, application-specific integrated circuits (ASICs), FPGAs, or other equivalent integrated or discrete logic circuits. Therefore, the term "processor" as used herein may refer to any of the foregoing structures or any other structure suitable for implementing the techniques described herein. Furthermore, in some aspects, the functionality described herein may be provided within dedicated hardware and / or software modules configured to perform the techniques described herein. Moreover, these techniques may be implemented entirely within one or more circuit or logic elements.

[0078] The techniques disclosed herein can be implemented in various devices or apparatuses including integrated circuits (ICs) or a set of ICs (e.g., chipsets). Various components, modules, or units are described in this disclosure to emphasize functional aspects of a device configured to perform the disclosed techniques, but they do not necessarily need to be implemented by different hardware units. Instead, various units may be combined with or provided by a collection of interoperable hardware units (including one or more processors as described above) incorporating suitable software and / or firmware.

Claims

1. An accelerometer system, the accelerometer system comprising: A resonator beam, comprising a mechanical beam extending along a longitudinal axis from a first end to a second end, wherein the mechanical beam comprises: A first oscillating surface, extending along the longitudinal axis from the first end to the second end, wherein the first oscillating surface is represented by a first sinusoidal pattern; and A second oscillating surface, which is opposite to the first oscillating surface, wherein the second oscillating surface extends from the first end to the second end along the longitudinal axis, and wherein the second oscillating surface is represented by a second sine pattern; Inspect the quality block; A light-emitting device configured to generate a light signal based on an error signal; Modulator, the modulator being configured to: Receive the optical signal; In response to receiving the optical signal, a modulated optical signal is generated; and The modulated optical signal is output to the resonator beam; An optical receiver, the optical receiver being configured to: The optical signal passing through the resonator beam is received from the resonator beam, wherein the optical signal passing through the resonator beam represents a portion of the modulated optical signal passing through the resonator beam, and the optical signal passing through the resonator beam indicates the resonant frequency of the resonator beam; Reflected optical signals are received from the resonator beam, wherein the reflected optical signals represent a portion of the modulated optical signal reflected by the resonator beam, wherein the first oscillating surface and the second oscillating surface define one or more frequency bands that are reflected by the resonator beam as part of the reflected optical signal; and wherein the first oscillating surface and the second oscillating surface define one or more frequency bands that are passed through the resonator beam as part of the transmitted optical signal; and One or more electrical signals are generated based on the transmitted optical signal and the reflected optical signal; and Processing circuit, the processing circuit being configured to: The error signal is generated based on one or more parameters indicated by the one or more electrical signals of the reflected optical signal; and Acceleration is determined based on the resonant frequency indicated by the one or more electrical signals. The inspection quality block is configured as follows: In response to the acceleration, a force is applied to the resonator beam, wherein the force causes the resonator beam to vibrate at the resonant frequency, wherein the force is orthogonal to the longitudinal axis of the resonator beam, and The force described therein results in the length of the resonator beam as follows: Increase along the longitudinal axis; or Reduced along the longitudinal axis.

2. The accelerometer system according to claim 1, wherein the light-emitting device is a first light-emitting device, the error signal is a first error signal, the light signal is a first light signal, the modulator is a first modulator, the modulated light signal is a first modulated light signal, the transmitted light signal is the transmitted first light signal, the reflected light signal is the reflected first light signal, the resonant frequency is a first resonant frequency, and the accelerometer system further comprises: A second light-emitting device, configured to generate a second light signal based on a second error signal; The second modulator is configured as follows: Receive the second optical signal; In response to receiving the second optical signal, a modulated second optical signal is generated; as well as The modulated second optical signal is output to the resonator beam. The optical receiver is further configured as follows: A second optical signal is received from the resonator beam, wherein the second optical signal represents a portion of the modulated second optical signal passing through the resonator beam, and the second optical signal indicates a second resonant frequency of the resonator beam; The second optical signal reflected from the resonator beam is received, wherein the reflected second optical signal represents a portion of the modulated second optical signal reflected by the resonator beam; as well as The one or more electrical signals are generated based on the transmitted second optical signal and the reflected second optical signal, and The processing circuit is further configured as follows: The second error signal is generated based on one or more parameters of the reflected second optical signal indicated by the one or more electrical signals; as well as The acceleration is determined based on the first resonant frequency and the second resonant frequency indicated by the one or more electrical signals.

3. The accelerometer system of claim 2, wherein the optical receiver generates the one or more electrical signals to reflect the difference between the first resonant frequency and the second resonant frequency, and wherein the processing circuitry is configured to determine the acceleration based on the difference between the first resonant frequency and the second resonant frequency.

4. The accelerometer system of claim 2, wherein the first modulator is configured to transmit the modulated first optical signal to a first end of the resonator beam, and wherein the second modulator is configured to transmit the modulated second optical signal to a second end of the resonator beam.

5. The accelerometer system according to claim 2, wherein the mechanical beam comprises: A first oscillating surface extends along the longitudinal axis from the first end to the second end; and A second oscillating surface, opposite to the first oscillating surface, wherein the second oscillating surface extends along the longitudinal axis from the first end to the second end. Wherein the first oscillating surface causes the mechanical beam to vibrate at the first resonant frequency, and The second oscillating surface causes the mechanical beam to vibrate at the second resonant frequency.

6. The accelerometer system of claim 5, wherein the first oscillation pattern of the first oscillation surface is offset along the longitudinal axis from the second oscillation pattern of the second oscillation surface such that one or more peaks of the first oscillation pattern are aligned with one or more valleys of the second oscillation pattern.

7. The accelerometer system of claim 6, wherein the amplitude of the first oscillation pattern decreases along the longitudinal axis from the first end to the center of the mechanical beam, wherein the amplitude of the first oscillation pattern increases along the longitudinal axis from the center of the mechanical beam to the second end, wherein the amplitude of the second oscillation pattern decreases along the longitudinal axis from the first end to the center of the mechanical beam, and wherein the amplitude of the second oscillation pattern increases along the longitudinal axis from the center of the mechanical beam to the second end.

8. The accelerometer system of claim 1, wherein the resonant frequency is a first resonant frequency, the acceleration is a first acceleration, the force is a first force, and wherein the test mass block is configured as follows: In response to the second acceleration in the second direction applied by the accelerometer system, a second force is applied to the resonator beam, causing the resonator beam to vibrate at a second resonant frequency. Wherein the first direction represents the positive direction along the axis orthogonal to the longitudinal axis of the resonator beam, and The second direction refers to the negative direction of the axis orthogonal to the longitudinal axis of the resonator beam.

9. A method, the method comprising: The light-emitting device generates a light signal based on an error signal; The optical signal is received by the modulator; The modulator generates a modulated optical signal in response to receiving the optical signal; The modulated optical signal is output to a resonator beam by the modulator, the resonator beam including a mechanical beam extending along a longitudinal axis from a first end to a second end, wherein the mechanical beam includes: A first oscillating surface, extending along the longitudinal axis from the first end to the second end, wherein the first oscillating surface is represented by a first sinusoidal pattern; and A second oscillating surface, which is opposite to the first oscillating surface, wherein the second oscillating surface extends from the first end to the second end along the longitudinal axis, and wherein the second oscillating surface is represented by a second sine pattern; A light receiver receives a passing light signal from the resonator beam, wherein the passing light signal represents a portion of the modulated light signal passing through the resonator beam, and the passing light signal indicates the resonant frequency of the resonator beam; The optical receiver receives a reflected optical signal from the resonator beam, wherein the reflected optical signal represents a portion of the modulated optical signal reflected by the resonator beam, wherein the first oscillating surface and the second oscillating surface define one or more frequency bands, which are reflected by the resonator beam as part of the reflected optical signal; and wherein the first oscillating surface and the second oscillating surface define one or more frequency bands, which are passed through the resonator beam as part of the passed optical signal; The optical receiver generates one or more electrical signals based on the transmitted optical signal and the reflected optical signal; The error signal is generated by the processing circuit based on one or more parameters indicated by the one or more electrical signals of the reflected light signal; and The processing circuit determines the acceleration based on the resonant frequency indicated by the one or more electrical signals; and A force is applied to the resonator beam by a test mass block in response to the acceleration, wherein the force causes the resonator beam to vibrate at the resonant frequency, and wherein the force is orthogonal to the longitudinal axis of the resonator beam. The force described therein results in the length of the resonator beam as follows: Increase along the longitudinal axis; or Reduced along the longitudinal axis.

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