Time-varying signal sensing method and system of echo wall mode microcavity, medium and equipment

Abstract

The invention provides a time-varying signal sensing method and system of an echo wall mode microcavity, a medium and equipment. The time-varying signal sensing method of the echo wall mode microcavity comprises the steps that S1, a weak measurement auxiliary echo wall mode microcavity self-adaptive sensing platform used for time-varying signal sensing is built; s2, sensing a time-varying signal through the echo wall mode microcavity, and introducing a time-varying phase on a sensing platform; and S3, receiving the light intensity of the echo wall mode microcavity sensing platform assisted by weak measurement through a photoelectric detector and a balance detector, calculating the size of a current time-varying phase, and further solving the size of a current time-varying signal until the measurement is finished. The weak measurement technology is introduced into echo wall mode microcavity sensing for assistance, compared with the prior art, the sensing interval of the echo wall mode microcavity is expanded, and time-varying signal sensing in a wide dynamic range is further achieved on the basis of high-sensitivity sensing.

Description

Technical Field

[0001] The present invention relates to the technical fields of quantum optics and optoelectronic signal detection. Specifically, it relates to a method, system, medium and device for sensing time-varying signals of a whispering gallery mode microcavity. In particular, it relates to a method and system for sensing time-varying signals with a wide dynamic range of a whispering gallery mode microcavity assisted by weak measurement. Background Art

[0002] In recent years, due to the high quality factor and small mode volume of the whispering gallery mode microcavity, the whispering gallery microcavity can greatly enhance the interaction between photons and matter, and has been widely applied in aspects such as acoustic and vibration sensing, refractive index sensing, temperature sensing, pressure sensing, magnetic field sensing, biological sensing, chemical gas sensing, etc. When the external environment is disturbed, the transmission spectrum line of the whispering gallery mode microcavity will change, thereby realizing the determination of physical parameters. In the existing sensing schemes based on the whispering gallery mode microcavity, usually a single optical mode of the microcavity is used for sensing. For the measurement of time-varying signals, a single-frequency laser is used to observe the change in intensity at a fixed wavelength. However, its working range is only limited to the region near the resonance peak, which greatly limits the application of the whispering gallery mode microcavity sensing in practical scenarios. Measuring the phase change of the whispering gallery mode microcavity caused by the disturbance of the external environment can also realize the sensing of time-varying signals, but the optical phase cannot be directly measured. The weak measurement technology can convert this phase into a relative phase difference, and amplify it by setting pre-selection states and post-selection states that are close to being orthogonal to achieve high-sensitivity measurement.

[0003] Aiming at the deficiencies of the existing technology, the present invention introduces weak measurement technology for assistance in the sensing of the whispering gallery mode microcavity. Compared with the existing technology, on the basis of ensuring high-sensitivity sensing, the sensing interval of the whispering gallery mode microcavity is further expanded, and on the basis of high-sensitivity sensing, the sensing of time-varying signals with a wide dynamic range is realized.

[0004] Patent document CN112113923A discloses a whispering gallery mode microbubble cavity-coupled CO2 sensor and a manufacturing method thereof. After the optical signal emitted by the amplified spontaneous emission light source is coupled into the microbubble cavity through an optical fiber taper, the optical signal is coupled with the PHMB solid film on the inner wall of the microbubble cavity to form a coupled optical signal. Then, the coupled optical signal is coupled into a spectrometer through an optical fiber taper. Since the PHMB solid film reacts with CO2 gas, the refractive index of the PHMB solid film changes, so that the position of the spectral absorption peak corresponding to the coupled optical signal received by the spectrometer shifts. Then, the corresponding CO2 gas concentration is matched from a pre-established relational database to obtain the concentration of the CO2 gas to be measured. However, this patent cannot completely solve the existing technical problems and cannot meet the requirements of the present invention. Summary of the Invention

[0005] Aiming at the defects in the prior art, the purpose of the present invention is to provide a method, system, medium and device for sensing time-varying signals of a whispering gallery mode microcavity.

[0006] The method for sensing time-varying signals of a whispering gallery mode microcavity provided by the present invention includes:

[0007] Step S1: Build an adaptive sensing platform for a whispering gallery mode microcavity assisted by weak measurement for time-varying signal sensing;

[0008] Step S2: Sense the time-varying signal through the whispering gallery mode microcavity and introduce a time-varying phase in the sensing platform;

[0009] Step S3: Receive the light intensity of the whispering gallery mode microcavity sensing platform assisted by weak measurement through a photodetector and a balanced detector, calculate the magnitude of the current time-varying phase, and then solve the magnitude of the current time-varying signal until the measurement ends.

[0010] Preferably, the step S1 includes:

[0011] Output a single-frequency light with a frequency of ω0 through a single-frequency light source, and the single-frequency light is modulated into a preselected state after passing through a preselection process Among them, |H> represents horizontally polarized light, that is, H light; |V> represents vertically polarized light, that is, V light;

[0012] In the weak coupling process, the preselected light is split into two orthogonally polarized lights after passing through a polarization beam splitter: H light and V light. The H light and V light respectively pass through mirrors, coupling devices and mirrors from two opposite directions and converge through the polarization beam splitter; among them, the coupling device is coupled to the whispering gallery mode microcavity;

[0013] The coupling device includes a tapered fiber, a prism fiber, and a lens fiber;

[0014] The converged light is split into two paths of light after passing through a beam splitter: the first path of light and the second path of light; the first path of light is divided into: the 1-1 path of light and the 1-2 path of light after passing through a polarization beam splitter, and are respectively received by a first photodetector and a second photodetector; the second path of light is split into two paths of light after passing through a beam splitter: the 2-1 path of light and the 2-2 path of light, and post-selection is respectively performed;

[0015] In the post-selection process, the 2-1 path of light is projected onto a post-selection state one |f1> that is close to being orthogonal to the preselected state in the first post-selection process. After the 2-2 path of light passes through a mirror, it is projected onto a post-selection state two |f2> that is close to being orthogonal to the preselected state in the second post-selection process; the light intensities of the two paths are collected by a balanced detector; among them, the post-selection angle between the post-selection state one and the preselection is ε1, expressed as The post-selection angle between the post-selection state two and the preselection is ε2, expressed as The post - selected angle one and the post - selected angle two are opposite to each other, ε1 = -ε2, and let ε = |ε1| = |ε2|;

[0016] The first photodetector, the second photodetector and the balanced detector are connected to a computer for data processing.

[0017] Preferably, the step S2 includes:

[0018] In weak coupling, the coupling device is coupled with the whispering - gallery - mode microcavity. Under the action of an external signal, the whispering - gallery - mode microcavity causes changes in the effective refractive index and perimeter due to the signal action, and then causes a change in the resonant frequency, that is, ω c (t)=f(x(t)), where x is the signal to be measured, and f(·) is the relationship between the resonant frequency and the signal to be measured;

[0019] At this time, the output optical fields at both ends of the coupling device change. The output optical field of the H - polarized light is The output optical field of the V - polarized light is where, E in is the input optical field of the coupling device; κ0 is the intrinsic loss of the whispering - gallery - mode microcavity; κ e is the coupling loss of the whispering - gallery - mode microcavity; ω Hc (t) and ω Vc (t) are the resonant frequencies of the H - polarized light and V - polarized light of the whispering - gallery - mode microcavity respectively;

[0020] The above - mentioned change relationship leads to changes introduced in the H - polarized light and V - polarized light. On the one hand, it causes changes in the optical field intensities of the H - polarized light and V - polarized light, and causes changes in the output intensities of the 1 - 1 path light and 1 - 2 path light where, I0 is the optical intensity of the light source, On the other hand, a change in phase is introduced in the H - polarized light and V - polarized light Then the changes introduced in the H - polarized light and V - polarized light are expressed as where e is the natural exponential and i is the imaginary unit.

[0021] Preferably, the step S3 includes:

[0022] Using the optical intensity as the detection index, under the condition of satisfying weak measurement where The optical intensity output from the 2 - 1 path is expressed as

[0023] The optical intensity output from the 2 - 2 path is expressed as

[0024] Select the intensity contrast as the observation index, for Perform real-time estimation to obtain the estimated values at each moment Furthermore, according to the response relationship of the whispering gallery mode microcavity to the signal, the estimation of x(t) of the signal to be measured is obtained;

[0025] When T H (t) ≈ T V (t), the intensity contrast of the phase change caused by the signal is written as: When T H (t) and T V (t) differ by more than the preset range, according to T H (t) or T V (t) changes to achieve the estimation of the sensing signal.

[0026] According to the time-varying signal sensing system of the whispering gallery mode microcavity provided by the present invention, it includes:

[0027] Module M1: Build a whispering gallery mode microcavity adaptive sensing platform assisted by weak measurement for time-varying signal sensing;

[0028] Module M2: Sense the time-varying signal through the whispering gallery mode microcavity and introduce a time-varying phase into the sensing platform;

[0029] Module M3: Receive the light intensity of the whispering gallery mode microcavity sensing platform assisted by weak measurement through a photodetector and a balanced detector, calculate the magnitude of the current time-varying phase, and then solve the magnitude of the current time-varying signal until the measurement ends.

[0030] Preferably, the module M1 includes:

[0031] Output a single-frequency light with a frequency of ω0 through a single-frequency light source, and the single-frequency light is modulated into a preselected state after a preselection process Among them, |H> represents horizontally polarized light, that is, H light; |V> represents vertically polarized light, that is, V light;

[0032] In the weak coupling process, the preselected light is split into two orthogonally polarized lights after passing through a polarization beam splitter: H light and V light. The H light and V light respectively pass through mirrors, coupling devices, and mirrors from opposite directions and converge through the polarization beam splitter; among them, the coupling device is coupled to the whispering gallery mode microcavity;

[0033] The coupling device includes a tapered fiber, a prism fiber, and a lens fiber;

[0034] The combined light is split into two paths of light by a beam splitter: the first path of light and the second path of light; the first path of light is divided into: the 1-1 path of light and the 1-2 path of light after passing through a polarization beam splitter, and is received by a first photodetector and a second photodetector respectively; the second path of light is split into two paths of light by a beam splitter: the 2-1 path of light and the 2-2 path of light, and post-selections are performed respectively.

[0035] During the post-selection process, the 2-1 path of light is projected onto a post-selection state one |f1> that is close to being orthogonal to the pre-selection state during the first post-selection process, and the 2-2 path of light is projected onto a post-selection state two |f2> that is close to being orthogonal to the pre-selection state after passing through a mirror during the second post-selection process; the intensities of the two paths of light are collected by a balanced detector; among them, the post-selection angle between the post-selection state one and the pre-selection is ε1, expressed as The post-selection angle between the post-selection state two and the pre-selection is ε2, expressed as The post-selection angle one and the post-selection angle two are opposite to each other, ε1 = -ε2, and let ε = |ε1| = |ε2|;

[0036] The first photodetector, the second photodetector, and the balanced detector are connected to a computer for data processing.

[0037] Preferably, the module M2 includes:

[0038] In weak coupling, the coupling device is coupled to the whispering gallery mode microcavity. Under the action of an external signal, the whispering gallery mode microcavity causes changes in the effective refractive index and perimeter due to the signal action, thereby causing a change in the resonant frequency, that is, ω c (t) = f(x(t)), where x is the signal to be measured, and f(·) is the relationship between the resonant frequency and the signal to be measured;

[0039] At this time, the output optical fields at both ends of the coupling device change. The output optical field of the H light is The output optical field of the V light is Among them, E in is the input optical field of the coupling device; κ0 is the intrinsic loss of the whispering gallery mode microcavity; κ e is the coupling loss of the whispering gallery mode microcavity; ω Hc (t) and ω Vc (t) are the resonant frequencies of the H light and the V light of the whispering gallery mode microcavity respectively;

[0040] The above change relationship leads to changes introduced in the H light and the V light. On the one hand, it causes changes in the optical field intensities of the H light and the V light, and causes changes in the output intensities of the 1-1 path of light and the 1-2 path of light Among them, I0 is the optical intensity of the light source, On the other hand, a changing phase is introduced in the H light and the V light The changes introduced in the H light and V light are expressed as where e is the natural exponent and i is the imaginary unit.

[0041] Preferably, the module M3 includes:

[0042] Using the light intensity as the detection index, under the condition of satisfying weak measurement when The light intensity of the 2-1 path light output is expressed as

[0043] The light intensity of the 2-2 path light output is expressed as

[0044] Select the intensity contrast as the observation index, for perform real-time estimation to obtain the estimated value at each moment Furthermore, according to the response relationship of the whispering gallery mode microcavity to the signal, obtain the estimation of x(t) of the signal to be measured;

[0045] When T H (t)≈T V (t), the intensity contrast for the phase change caused by the signal is written as: When T H (t) and T V (t) differ by more than the preset range, according to T H (t) or T V (t) changes to achieve the estimation of the sensing signal.

[0046] According to the computer-readable storage medium storing a computer program provided by the present invention, when the computer program is executed by a processor, the steps of the time-varying signal sensing method of the whispering gallery mode microcavity are implemented.

[0047] According to the electronic device provided by the present invention, including a memory, a processor, and a computer program stored on the memory and executable on the processor, when the computer program is executed by the processor, the steps of the time-varying signal sensing method of the whispering gallery mode microcavity are implemented.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) From the perspective of the overall technology, the present invention overcomes the deficiency of small dynamic range in the existing time-varying parameter sensing based on the whispering gallery mode microcavity, and further realizes time-varying signal sensing with a wide dynamic range on the basis of high-sensitivity sensing, expanding the application range of microcavity sensing;

[0050] (2) From the perspective of the application scope, the present invention has a wide scope of action and can be used for time-varying signals such as refractive index, temperature, pressure, acoustic signal, etc. that can cause deformation of the microcavity and the photoelastic coefficient of the material;

[0051] (3) From the perspective of technological improvement, the present invention expands the application scenarios of many measurement systems based on weak measurement theory and promotes the application of weak measurement in quantum open systems. Description of the Drawings

[0052] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objectives, and advantages of the present invention will become more apparent:

[0053] Figure 1 It is a schematic diagram of the principle of the present invention;

[0054] Reference Signs in the Drawings

[0055] Single-frequency light source - 1 Whispering gallery mode microcavity - 7 Post-selection process one - 13

[0056] Pre-selection process - 2 Beam splitter - 8 Mirror - 14

[0057] Polarizing beam splitter - 3 Polarizing beam splitter - 9 Post-selection process two - 15

[0058] Mirror - 4 Photoelectric detector one - 10 Balanced detector - 16

[0059] Coupling device - 5 Photoelectric detector two - 11 Computer - 17

[0060] Mirror - 6 Beam splitter - 12 Detailed Embodiment

[0061] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all fall within the protection scope of the present invention.

[0062] Embodiment 1

[0063] The present invention provides a method for sensing time-varying signals with a wide dynamic range in a whispering gallery mode microcavity assisted by weak measurement, as Figure 1As shown in the figure, it includes: a single-frequency light source 1; a pre-selection process 2 (composed of a half-wave plate, a polarizer, and a quarter-wave plate); a polarization beam splitter 3; a mirror 4; a coupling device 5; a mirror 6; a whispering gallery mode microcavity 7; a beam splitter 8; a polarization beam splitter 9; a photodetector 10; a photodetector 11; a beam splitter 12; a post-selection process 13 (composed of a half-wave plate, a polarizer, and a quarter-wave plate); a mirror 14; a post-selection process 15 (composed of a half-wave plate, a polarizer, and a quarter-wave plate); a balanced detector 16; and a computer 17.

[0064] The method includes the following steps:

[0065] Step S1: Build a whispering gallery mode microcavity adaptive sensing platform assisted by weak measurement for time-varying signal sensing;

[0066] Step S2: The whispering gallery mode microcavity 5 senses the time-varying signal and introduces a time-varying phase into the sensing platform;

[0067] Step S3: Receive the light intensity of the whispering gallery mode microcavity sensing platform assisted by weak measurement through the photodetector 11 and the balanced detector 18, calculate the magnitude of the current time-varying phase, and then solve the magnitude of the current time-varying signal until the measurement ends.

[0068] The implementation process of the above step S1 is as follows:

[0069] The single-frequency light source 1 outputs single-frequency light with a frequency of ω0.

[0070] The single-frequency light is modulated into a pre-selected state after passing through the pre-selection process 2 where, |H> represents horizontally polarized light, i.e., H light, and |V> represents vertically polarized light, i.e., V light;

[0071] In the weak coupling process, the pre-selected light is split into two orthogonally polarized lights: H light and V light after passing through the polarization beam splitter 3. The H light and V light converge through the mirror 4, the coupling device 5, and the mirror 6 from the front and back directions respectively through the polarization beam splitter 3. Among them, the coupling device 5 is coupled with the whispering gallery mode microcavity 7. Optionally, the coupling device 4 can be a tapered fiber, a prism fiber, a lens fiber, etc.

[0072] The converged light is split into two paths of light by the beam splitter 8: the first path of light and the second path of light. The first path of light is divided into: the 1-1 path of light and the 1-2 path of light after passing through the polarization beam splitter 9, and are respectively received by the photodetector 10 and the photodetector 11. The second path of light is split into two paths of light by the beam splitter 12: the 2-1 path of light and the 2-2 path of light, and post-selections are respectively performed on them.

[0073] In the post-selection process, the 2-1 path light is projected onto the post-selection state one |f1> that is nearly orthogonal to the pre-selection state during the first post-selection process 13. After the 2-2 path light passes through the mirror 14, it is projected onto the post-selection state two |f2> that is nearly orthogonal to the pre-selection state during the second post-selection process 15. The intensities of the two paths of light are collected by the balanced detector 16. Among them, the post-selection angle between the post-selection state one and the pre-selection is ε1, which can be expressed as The post-selection angle between the post-selection state two and the pre-selection is ε2, which can be expressed as Preferably, the first post-selection angle and the second post-selection angle are opposite to each other, ε1 = -ε2, and let ε = |ε1| = |ε2|.

[0074] The first photodetector 10, the second photodetector 11, and the balanced detector 16 are connected to the computer 17 for data processing.

[0075] The implementation process of the step S2 is as follows:

[0076] In weak coupling, the coupling device is coupled to the whispering gallery mode microcavity. Under the action of an external signal, the whispering gallery mode microcavity will cause changes in the effective refractive index and perimeter due to the signal action, and further cause changes in the resonance frequency, that is, ω c (t) = f(x(t)), where x is the signal to be measured, and f(·) is the relationship between the resonance frequency and the signal to be measured.

[0077] At this time, the optical fields output at both ends of the coupling device will change. The output optical field of the H light is The output optical field of the V light is Among them, E in is the input optical field of the coupling device; κ0 is the intrinsic loss of the whispering gallery mode microcavity; κ e is the coupling loss of the whispering gallery mode microcavity; ω Hc (t) and ω Vc (t) are the resonance frequencies of the H light and V light of the whispering gallery mode microcavity respectively.

[0078] The above variation relationship will cause changes introduced in the H light and V light. On the one hand, it causes changes in the optical field intensities of the H light and V light. Correspondingly, it will cause changes in the output intensities of the 1-1 path light and the 1-2 path light Among them, I0 is the optical intensity of the light source, On the other hand, a changing phase is introduced in the H light and V light Then the changes introduced in the H light and V light can be expressed as where e is the natural exponent and i is the imaginary unit.

[0079] The implementation process of the step S3 is as follows:

[0080] Using the light intensity as the detection index, when the weak measurement condition is satisfied wherein The light intensity of the 2-1 channel light output can be expressed as The light intensity of the 2-2 channel light output can be expressed as

[0081] Select the intensity contrast as the observation index, and perform real-time estimation on to obtain the estimated values at each moment Furthermore, according to the response relationship of the whispering gallery mode microcavity to the signal, the estimation of x(t) of the signal to be measured is obtained.

[0082] When T H (t)≈T V (t), the intensity contrast of the phase change caused by the signal for the method can be written as It can also achieve high-sensitivity estimation. When the values of T H (t) and T V (t) have a large difference, that is, when ImAw(t) cannot ensure amplification, the estimation of the sensing signal can be achieved according to the change of T H (t) or T V (t).

[0083] Embodiment 2

[0084] The present invention also provides a whispering gallery mode microcavity adaptive time-varying signal sensing system assisted by weak measurement. The whispering gallery mode microcavity adaptive time-varying signal sensing system assisted by weak measurement can be implemented by executing the process steps of the whispering gallery mode microcavity adaptive time-varying signal sensing method. That is, those skilled in the art can understand the whispering gallery mode microcavity adaptive time-varying signal sensing method as a preferred embodiment of the whispering gallery mode microcavity adaptive time-varying signal sensing system.

[0085] The present invention provides a whispering gallery mode microcavity adaptive time-varying signal sensing system assisted by weak measurement, as Figure 1As shown in the figure, it includes: a single-frequency light source 1; a pre-selection process 2 (constituted by a half-wave plate, a polarizer, and a quarter-wave plate); a polarization beam splitter 3; a coupling device 4; a whispering gallery mode microcavity 5; a mirror 6; a mirror 7; a bias phase 8; a beam splitter 9; a polarization beam splitter 10; a photodetector 11; a beam splitter 12; a reference phase one 13; a post-selection process one 14 (constituted by a half-wave plate, a polarizer, and a quarter-wave plate); a mirror 15; a reference phase two 16; a post-selection process two 17 (constituted by a half-wave plate, a polarizer, and a quarter-wave plate); a balanced detector 18; a computer 19.

[0086] The system includes the following modules:

[0087] Module M1: Build a whispering gallery mode microcavity adaptive sensing platform assisted by weak measurement for time-varying signal sensing;

[0088] Module M2: The whispering gallery mode microcavity 5 senses the time-varying signal and introduces a time-varying phase into the sensing platform;

[0089] Module M3: Receive the light intensity of the whispering gallery mode microcavity sensing platform assisted by weak measurement through the photodetector 11 and the balanced detector 18, calculate the magnitude of the current time-varying phase, and then solve the magnitude of the current time-varying signal until the measurement ends.

[0090] The implementation process of the module M1 is as follows:

[0091] The single-frequency light source 1 outputs a single-frequency light with a frequency of ω0.

[0092] The single-frequency light is modulated into a pre-selection state after passing through the pre-selection process 2 Among them, |H> represents horizontally polarized light, that is, H light, and |V> represents vertically polarized light, that is, V light;

[0093] In the weak coupling process, the pre-selected light is split into two orthogonally polarized lights: H light and V light after passing through the polarization beam splitter 3. The H light and V light respectively converge through the mirrors 4, the coupling device 5, and the mirror 6 from the positive and negative directions through the polarization beam splitter 3. Among them, the coupling device 5 is coupled to the whispering gallery mode microcavity 7. Optionally, the coupling device 4 can be a tapered fiber, a prism fiber, a lens fiber, etc.

[0094] The converged light is split into two paths of light through the beam splitter 8: the first path of light and the second path of light. The first path of light is divided into: the 1-1 path of light and the 1-2 path of light after passing through the polarization beam splitter 9, and are respectively received by the first photodetector 10 and the second photodetector 11. The second path of light is split into two paths of light through the beam splitter 12: the 2-1 path of light and the 2-2 path of light, and post-selection is respectively performed.

[0095] In the post-selection process, the 2-1 path light is projected onto the post-selection state one |f1> that is close to being orthogonal to the pre-selection state in the first post-selection process 13. After the 2-2 path light passes through the mirror 14, it is projected onto the post-selection state two |f2> that is close to being orthogonal to the pre-selection state in the second post-selection process 15. The light intensities of the two paths are collected by the balanced detector 16. Among them, the post-selection angle between the post-selection state one and the pre-selection is ε1, which can be expressed as The post-selection angle between the post-selection state two and the pre-selection is ε2, which can be expressed as Preferably, the first post-selection angle and the second post-selection angle are opposite to each other, ε1 = -ε2, and let ε = |ε1| = |ε2|.

[0096] The first photodetector 10, the second photodetector 11, and the balanced detector 16 are connected to the computer 17 for data processing.

[0097] The implementation process of the module M2 is as follows:

[0098] In weak coupling, the coupling device is coupled with the whispering gallery mode microcavity. Under the action of an external signal, the whispering gallery mode microcavity will cause changes in the effective refractive index and perimeter due to the signal action, and further cause changes in the resonance frequency, that is, ω c (t) = f(x(t)), where x is the signal to be measured, and f(·) is the relationship between the resonance frequency and the signal to be measured.

[0099] At this time, the optical fields output at both ends of the coupling device will change. The output optical field of the H light is The output optical field of the V light is Among them, E in is the input optical field of the coupling device; κ0 is the intrinsic loss of the whispering gallery mode microcavity; κ e is the coupling loss of the whispering gallery mode microcavity; ω Hc (t) and ω Vc (t) are the resonance frequencies of the H light and V light of the whispering gallery mode microcavity respectively.

[0100] The above change relationship will cause changes introduced in the H light and V light. On the one hand, it causes changes in the optical field intensities of the H light and V light. Correspondingly, it will cause changes in the output intensities of the 1-1 path light and the 1-2 path light Among them, I0 is the light intensity of the light source, On the other hand, a changing phase is introduced in the H light and V light Then the changes introduced in the H light and V light can be expressed as where e is the natural exponent and i is the imaginary unit.

[0101] The implementation process of the module M3 is as follows:

[0102] Using the light intensity as the detection index, when the weak measurement condition is satisfied wherein The light intensity of the 2-1 channel light output can be expressed as The light intensity of the 2-2 channel light output can be expressed as

[0103] Select the intensity contrast as the observation index, and perform real-time estimation on to obtain the estimated values at each moment Furthermore, according to the response relationship of the whispering gallery mode microcavity to the signal, the estimation of x(t) of the signal to be measured is obtained.

[0104] When T H (t)≈T V (t), the intensity contrast of the phase change caused by the signal for the method can be written as, It can also achieve high-sensitivity estimation. When the values of T H (t) and T V (t) have a large difference, that is, when ImAw(t) cannot ensure amplification, the estimation of the sensing signal can be realized according to the change of T H (t) or T V (t).

[0105] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0106] Those skilled in the art know that in addition to implementing the systems, devices and their respective modules provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the systems, devices and their respective modules provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. to achieve the same program. Therefore, the systems, devices and their respective modules provided by the present invention can be regarded as a kind of hardware component, and the modules included therein for implementing various programs can also be regarded as the structures within the hardware component; the modules for implementing various functions can also be regarded as both software programs for implementing the method and the structures within the hardware component.

[0107] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined arbitrarily with each other.

Claims

1. A method for sensing time-varying signals of a whispering gallery mode microcavity, characterized in that, Including: Step S1: Build a whispering gallery mode microcavity adaptive sensing platform assisted by weak measurement for time-varying signal sensing; Step S2: Sense the time-varying signal through the whispering gallery mode microcavity and introduce a time-varying phase into the sensing platform; Step S3: Receive the light intensity of the whispering gallery mode microcavity sensing platform assisted by weak measurement through a photodetector and a balanced detector, calculate the magnitude of the current time-varying phase, and then solve the magnitude of the current time-varying signal until the measurement ends.

2. The time-varying signal sensing method of the whispering gallery mode microcavity according to claim 1, characterized in that The said step S1 includes: A single-frequency light source outputs single-frequency light with a frequency of ω0, and the single-frequency light is modulated into a preselected state after a preselection process. Among them, |H> represents horizontally polarized light, that is, H light; |V> represents vertically polarized light, that is, V light. In the weak coupling process, the pre-selected light is split into two orthogonally polarized lights by a polarization beam splitter: H light and V light. The H light and V light respectively pass through mirrors, coupling devices and mirrors from two opposite directions and converge via the polarization beam splitter. Among them, the coupling device is coupled with the whispering gallery mode microcavity; The said coupling device includes a tapered fiber, a prism fiber, and a lens fiber; The converged light is split into two paths of light by a beam splitter: the first path of light and the second path of light. The first path of light is split into: the 1-1 path of light and the 1-2 path of light by a polarization beam splitter and is received by a first photodetector and a second photodetector respectively. The second path of light is split into two paths of light by a beam splitter: the 2-1 path of light and the 2-2 path of light, and post-selection is performed respectively; In the post-selection process, the 2-1 path light is projected onto the post-selection state one |f1> which is close to being orthogonal to the pre-selection state in the first post-selection process. After the 2-2 path light passes through the mirror, it is projected onto the post-selection state two |f2> which is close to being orthogonal to the pre-selection state in the second post-selection process. The intensities of the two paths of light are collected by a balanced detector. Among them, the post-selection angle between the post-selection state one and the pre-selection is ε1, expressed as The post-selection angle between the post-selection state two and the pre-selection is ε2, expressed as The post-selection angle one and the post-selection angle two are opposite to each other, ε1 = -ε2, and let ε = |ε1| = |ε2|; e is the natural exponential, and i is the imaginary unit; The first photodetector, the second photodetector and the balanced detector are connected to a computer for data processing.

3. The time-varying signal sensing method of the whispering gallery mode microcavity according to claim 2, wherein The said step S2 includes: In weak coupling, the coupling device is coupled with the whispering gallery mode microcavity. Under the action of an external signal, the effective refractive index and perimeter of the whispering gallery mode microcavity change due to the signal, thereby causing a change in the resonant frequency, that is, ω c (t) = f(x(t)), where x is the signal to be measured, and f(·) is the relationship between the resonant frequency and the signal to be measured; At this time, the optical fields output at both ends of the coupling device change, and the output optical field of the H light is The output optical field of the V light is where E in is the input optical field of the coupling device; κ0 is the intrinsic loss of the whispering gallery mode microcavity; κ e is the coupling loss of the whispering gallery mode microcavity; ω Hc (t) and ω Vc (t) are the resonance frequencies of the H light and the V light of the whispering gallery mode microcavity, respectively; The above change relationship leads to changes introduced in the H light and V light. On the one hand, it causes changes in the optical field intensities of the H light and V light, resulting in changes in the output intensities of the light on the 1-1 path and the 1-2 path. where I0 is the optical intensity of the light source. On the other hand, a changing phase is introduced in the H light and V light. Then the changes introduced in the H light and V light are expressed as 4. The time-varying signal sensing method for the whispering gallery mode microcavity according to claim 3, wherein The said step S3 includes: Using the light intensity as the detection index, when the weak measurement condition is satisfied where the light intensity of the 2-1 channel optical output is expressed as The light intensities of the 2-2 optical outputs are expressed as Select the intensity contrast as the observation index, and perform real-time estimation on to obtain the estimated values at each moment Furthermore, according to the response relationship of the whispering gallery mode microcavity to the signal, the estimation of x(t) of the signal to be measured is obtained; When T H (t) ≈ T V (t), the intensity contrast for the phase change caused by the signal is written as: When T H (t) and T V (t) differ by more than a preset range, the sensing signal is estimated according to the change in T H (t) or T V (t).

5. A time-varying signal sensing system for a whispering gallery mode microcavity, characterized in that, Including: Module M1: Build a whispering gallery mode microcavity adaptive sensing platform assisted by weak measurement for time-varying signal sensing; Module M2: Sense the time-varying signal through the whispering gallery mode microcavity and introduce a time-varying phase into the sensing platform; Module M3: Receive the light intensity of the whispering gallery mode microcavity sensing platform assisted by weak measurement through a photodetector and a balanced detector, calculate the magnitude of the current time-varying phase, and then solve the magnitude of the current time-varying signal until the measurement ends.

6. The time-varying signal sensing system of the whispering gallery mode microcavity according to claim 5, characterized in that, The said module M1 includes: A single-frequency light source outputs single-frequency light with a frequency of ω0. After passing through the pre-selection process, the single-frequency light is modulated into a pre-selected state. Among them, |H> represents horizontally polarized light, that is, H light; |V> represents vertically polarized light, that is, V light. In the weak coupling process, the pre-selected light is split into two orthogonally polarized lights by a polarization beam splitter: H light and V light. The H light and V light respectively pass through mirrors, coupling devices and mirrors from two opposite directions and converge via the polarization beam splitter. Among them, the coupling device is coupled with the whispering gallery mode microcavity; The said coupling device includes a tapered fiber, a prism fiber, and a lens fiber; The converged light is split into two paths of light by a beam splitter: the first path of light and the second path of light. The first path of light is split into: the 1-1 path of light and the 1-2 path of light by a polarization beam splitter and is received by a first photodetector and a second photodetector respectively. The second path of light is split into two paths of light by a beam splitter: the 2-1 path of light and the 2-2 path of light, and post-selection is performed respectively; In the post-selection process, the 2-1 path light is projected in the first post-selection process onto a first post-selection state |f1> that is nearly orthogonal to the pre-selection state. After the 2-2 path light passes through the mirror, it is projected in the second post-selection process onto a second post-selection state |f2> that is nearly orthogonal to the pre-selection state. The intensities of the two paths of light are collected by a balanced detector. Among them, the post-selection angle between the first post-selection state and the pre-selection is ε1, expressed as The post-selection angle between the second post-selection state and the pre-selection is ε2, expressed as The first post-selection angle and the second post-selection angle are opposite to each other, ε1 = -ε2. Denote ε = |ε1| = |ε2|; e is the natural exponent, and i is the imaginary unit; The first photodetector, the second photodetector and the balanced detector are connected to a computer for data processing.

7. The time-varying signal sensing system of the whispering gallery mode microcavity according to claim 6, characterized in that, The said module M2 includes: In weak coupling, the coupling device is coupled with the whispering gallery mode microcavity. Under the action of an external signal, the effective refractive index and perimeter of the whispering gallery mode microcavity change due to the signal, thereby causing a change in the resonant frequency, that is, ω c (t) = f(x(t)), where x is the signal to be measured and f(·) is the relationship between the resonant frequency and the signal to be measured; At this time, the optical fields output at both ends of the coupling device change, and the output optical field of the H light is The output optical field of the V light is where E in is the input optical field of the coupling device; κ0 is the intrinsic loss of the whispering gallery mode microcavity; κ e is the coupling loss of the whispering gallery mode microcavity; ω Hc (t) and ω Vc (t) are the resonance frequencies of the H light and the V light of the whispering gallery mode microcavity, respectively. The above change relationship leads to changes introduced in the H light and V light. On the one hand, it causes changes in the optical field intensities of the H light and V light, resulting in changes in the output intensities of the light in the 1-1 path and 1-2 path. where I0 is the optical intensity of the light source. On the other hand, a changing phase is introduced in the H light and V light. Then the changes introduced in the H light and V light are expressed as 8. The time-varying signal sensing system of the whispering gallery mode microcavity according to claim 7, characterized in that The said module M3 includes: Using the light intensity as the detection index, when the weak measurement condition is satisfied where the light intensity of the 2-1 channel optical output is expressed as The light intensities of the 2-2 optical outputs are expressed as Select the intensity contrast as the observation index, and perform real-time estimation on to obtain the estimated values at each moment Furthermore, according to the response relationship of the whispering gallery mode microcavity to the signal, the estimation of x(t) of the signal to be measured is obtained; When T H (t)≈T V (t), the intensity contrast of the phase change caused by the signal is written as: When T H (t) and T V (t) differ by more than a preset range, the estimation of the sensing signal is achieved according to the change of T H (t) or T V (t).

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it realizes the steps of the time-varying signal sensing method of the whispering gallery mode microcavity according to any one of claims 1 to 4.

10. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the computer program is executed by a processor, it realizes the steps of the time-varying signal sensing method of the whispering gallery mode microcavity according to any one of claims 1 to 4.

Images