Phase characteristic measuring device and method of photoelectric balance detection system

Abstract

The invention discloses a phase characteristic measuring device of a photoelectric balance detection system, which can be applied to the field of signal processing and comprises a narrow linewidth laser for outputting an optical signal and outputting an upper optical signal and a lower optical signal from the optical signal through a beam splitter, a phase modulator for receiving the optical signal of the upper branch and generating a double-sideband modulation signal, the acousto-optic frequency shifter is used for receiving optical signals of a lower branch, carrying out optical carrier frequency shift and generating optical carrier frequency shift signals, the beam combiner is used for carrying out interference on the double-sideband modulation signals and the optical carrier frequency shift signals and inputting the signals to the photoelectric balance detection system, and the processor is used for obtaining sampling interference waveform data of the photoelectric balance detection system. And performing spectral analysis to obtain phase information at a preset frequency point. In this way, the modulated optical signal completely passes through the signal receiving chain of the photoelectric balance detection system, measurement errors caused by cascade matching of all assemblies are avoided, disassembly testing of each assembly is not needed, and therefore the complexity of phase characteristic measurement of the whole system is reduced.

Description

Technical Field

[0001] The present application relates to the field of signal processing technology, and in particular to a phase characteristic measurement device and method for a photoelectric balance detection system. Background Art

[0002] Optical heterodyne balanced detection is widely used in weak signal monitoring, fiber optic and space optical communications, and optoelectronic precision measurement. For example, current high-precision time and frequency transfer technology based on dual-comb linear optical sampling uses an optical heterodyne balanced detection system to detect and collect optical interference signals. When the optical interferometer system is in relative motion, the phase characteristics of the optoelectronic balanced detection system will greatly affect the accuracy of the measurement results, so it is necessary to measure the phase characteristics of the optoelectronic balanced detection system.

[0003] Existing measurement methods rely on separate component measurements. This is often difficult to perform in highly integrated acquisition systems, and simply overlaying the phase characteristics of each component for measurement ignores the impact of cascade matching, making it difficult to accurately assess the system's true phase characteristics.

[0004] Therefore, how to provide a phase characteristic measurement device for a photoelectric balance detection system to reduce the difficulty of measuring the phase characteristics of the photoelectric balance detection system and improve the measurement accuracy is a technical problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] The present application provides a phase characteristic measurement device for a photoelectric balance detection system to reduce the difficulty of measuring the phase characteristics of the photoelectric balance detection system and improve the measurement accuracy. The present application also provides a phase characteristic measurement method for a photoelectric balance detection system.

[0006] In a first aspect, the present application provides a phase characteristic measurement device for a photoelectric balance detection system, comprising:

[0007] Narrow linewidth lasers, beam splitters, phase modulators, acousto-optic frequency shifters, beam combiners, and processors;

[0008] The narrow linewidth laser is used to output an optical signal and output the optical signal as two optical signals, upper and lower, through a beam splitter;

[0009] The phase modulator is used to receive the optical signal of the add branch and generate a double-sideband modulated signal. The acousto-optic frequency shifter is used to receive the optical signal of the drop branch and perform optical carrier frequency shift to generate an optical carrier frequency-shifted signal.

[0010] The beam combiner is used to interfere the double-sideband modulated signal and the optical carrier frequency-shifted signal, and input the interference into the photoelectric balance detection system;

[0011] The processor is used to obtain sampled interference waveform data of the photoelectric balance detection system, and perform spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point.

[0012] Optionally, the device further comprises a first signal generator;

[0013] The first signal generator is used to output sinusoidal signals f1 and f2, where f2 is a k-order harmonic signal of f1 and the phase difference between the two is 0; the sinusoidal signals f1 and f2 are used to drive the phase modulator;

[0014] The double-sideband modulated signal is:

[0015] E u =A u exp(i2πf c t+iβ1sin(2πf1t+φ1)+iβ2sin(2πf2t+φ2));#

[0016] Among them, E u is a double-sideband modulated signal, f c is the optical carrier frequency, A u is the optical carrier amplitude, modulation depth β1=πV1 / V π1 , β2=πV2 / V π2 , with the modulation signal amplitude V1, V2, and the modulator half-wave voltage V π1 , V π2 is related to the size of , i represents the imaginary unit, φ1 and φ2 are the initial phases of the modulation signal.

[0017] Optionally, the device further comprises a second signal generator;

[0018] The second signal generator is used to output a sinusoidal signal f3, and the sinusoidal signal f3 is used to drive the acousto-optic frequency shifter;

[0019] The optical carrier frequency shift signal is:

[0020] E d =A d exp(i2πf c t+i2πf3t);

[0021] Among them, A d Indicates the amplitude of the signal, E d Indicates the optical carrier frequency shift signal.

[0022] Optionally, the interference waveform data is:

[0023]

[0024] Among them, J p(q)(·) represents the first kind of p(q) order Bessel function, and R(f)=G(f)exp(iφ(f)) represents the frequency response characteristics of the photoelectric balanced detection sampling system.

[0025] Optionally, the phase information at the preset frequency point is the phase information at the frequency point f3+nf1:

[0026] Φ(f3+nf1)=n(2πf1t+φ1)+φ(f3+nf1).

[0027] Optionally, the processor is specifically configured to:

[0028] Performing spectrum analysis on the interference waveform data to obtain spectrum analysis data;

[0029] Determining phase information corresponding to peak point data of the spectrum analysis data;

[0030] The phase information is unwrapped and the first-order linear phase is removed to obtain a residual phase, and the residual phase is used to characterize the additional phase characteristics of the photoelectric balance detection system.

[0031] In a second aspect, the present application further provides a method for measuring phase characteristics of a photoelectric balance detection system, the method comprising:

[0032] The narrow linewidth laser outputs an optical signal and outputs the optical signal through a beam splitter to output upper and lower optical signals;

[0033] The phase modulator receives the optical signal of the add branch and generates a double-sideband modulated signal. The acousto-optic frequency shifter receives the optical signal of the drop branch and performs optical carrier frequency shifting to generate an optical carrier frequency-shifted signal.

[0034] The beam combiner interferes the double-sideband modulated signal and the optical carrier frequency-shifted signal and inputs the interference into the photoelectric balance detection system;

[0035] The processor obtains sampled interference waveform data of the photoelectric balance detection system, and performs spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point.

[0036] Optionally, the acquiring of sampled interference waveform data of the photoelectric balance detection system and performing spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point includes:

[0037] Performing spectrum analysis on the interference waveform data to obtain spectrum analysis data;

[0038] Determining phase information corresponding to peak point data of the spectrum analysis data;

[0039] The phase information is unwrapped and the first-order linear phase is removed to obtain a residual phase, and the residual phase is used to characterize the additional phase characteristics of the photoelectric balance detection system.

[0040] Optionally, the method further includes:

[0041] The first signal generator is used to output sinusoidal signals f1 and f2, where f2 is a k-order harmonic signal of f1 and the phase difference between the two is 0; the sinusoidal signals f1 and f2 are used to drive the phase modulator;

[0042] The double-sideband modulated signal is:

[0043] E u =A u exp(i2πf c t+iβ1sin(2πf1t+φ1)+iβ2sin(2πf2t+φ2));#

[0044] Among them, E u is a double-sideband modulated signal, f c is the optical carrier frequency, A u is the optical carrier amplitude, modulation depth β1=πV1 / V π1 , β2=πV2 / V π2 , with the modulation signal amplitude V1, V2, and the modulator half-wave voltage V π1 , V π2 is related to the size of , i represents the imaginary unit, φ1 and φ2 are the initial phases of the modulation signal.

[0045] Optionally, the method further includes: a second signal generator configured to output a sinusoidal signal f3, and utilizing the sinusoidal signal f3 to drive the acousto-optic frequency shifter;

[0046] The optical carrier frequency shift signal is:

[0047] E d =A d exp(i2πf c t+i2πf3t);

[0048] Among them, A d Indicates the amplitude of the signal, E d Indicates the optical carrier frequency shift signal.

[0049] Optionally, the interference waveform data is:

[0050]

[0051] Among them, J p(q)(·) represents the first kind of p(q) order Bessel function, and R(f)=G(f)exp(iφ(f)) represents the frequency response characteristics of the photoelectric balanced detection sampling system.

[0052] Optionally, the phase information at the preset frequency point is the phase information at the frequency point f3+nf1:

[0053] Φ(f3+nf1)=n(2πf1t+φ1)+φ(f3+nf1).

[0054] In a third aspect, an embodiment of the present application provides a computer storage medium, wherein the computer storage medium stores a code. When the code is executed, the device executing the code implements the method described in any one of the first aspects above. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the following briefly introduces the drawings required for use in the embodiment or the prior art description. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0056] Figure 1 A structural diagram of a phase characteristic measurement device for a photoelectric balance detection system provided in an embodiment of the present application;

[0057] Figure 2 A schematic diagram of a spectrum analysis result provided in an embodiment of the present application;

[0058] Figure 3 A schematic diagram of phase characteristic measurement results of a photoelectric balance detection sampling system provided in an embodiment of the present application;

[0059] Figure 4 This is a flow chart of a method for measuring the phase characteristics of a photoelectric balance detection system provided in this application. DETAILED DESCRIPTION

[0060] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

[0061] It should be noted that the phase characteristic measurement device and method of the photoelectric balance detection system provided in this application are used in the field of signal processing. Of course, this is just an example and can also be used in other fields. The above is only an example and does not limit the application field of the device and method provided in this application.

[0062] In view of this, the present application proposes a phase characteristic measurement device for a photoelectric balance detection system, comprising: a narrow linewidth laser, a beam splitter, a phase modulator, an acousto-optic frequency shifter, a beam combiner, and a processor;

[0063] The narrow linewidth laser is used to output an optical signal and output the optical signal through a beam splitter as two optical signals, one up and one down. The phase modulator is used to receive the optical signal of the up branch and generate a double-sideband modulated signal. The acousto-optic frequency shifter is used to receive the optical signal of the down branch and perform optical carrier frequency shifting to generate an optical carrier frequency-shifted signal. The beam combiner is used to interfere with the double-sideband modulated signal and the optical carrier frequency-shifted signal and input them into the photoelectric balance detection system. The processor is used to obtain sampled interference waveform data of the photoelectric balance detection system and perform spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point. Electro-optical modulation is used to generate multiple phase-correlated optical frequency sidebands, which are detected by the photoelectric balance detection system and collected. After being processed by the processor and subjected to spectrum analysis, phase information reflecting the additional phase characteristics of the photoelectric balance detection system can be obtained. In this way, the modulated optical signal passes through the signal receiving chain of the photoelectric balance detection system completely, avoiding the measurement error caused by the cascade matching of each component and eliminating the need to disassemble and test each component, thereby reducing the complexity of the phase characteristic measurement of the entire system.

[0064] In order to make the technical personnel in this field better understand the present application scheme, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods. Figure 1 As shown, Figure 1 This is a structural diagram of a phase characteristic measurement device for a photoelectric balance detection system provided in an embodiment of the present application. Figure 1 As shown, the device includes:

[0065] Narrow linewidth laser 1, beam splitter 2, phase modulator 3, acousto-optic frequency shifter 4, beam combiner 5 and processor 6;

[0066] The narrow linewidth laser 1 can be used to output an optical signal and output the optical signal into two optical signals, an upper optical signal and an lower optical signal, via the beam splitter 2 .

[0067] The phase modulator 3 can be used to receive the optical signal of the add branch and generate a double-sideband modulated signal. The acousto-optic frequency shifter 4 can be used to receive the optical signal of the drop branch and perform optical carrier frequency shift to generate an optical carrier frequency-shifted signal.

[0068] The beam combiner 5 can be used to interfere the double-sideband modulated signal and the optical carrier frequency-shifted signal, and input them into the optoelectronic balance detection system.

[0069] The processor 6 can be used to obtain sampled interference waveform data of the photoelectric balance detection system, and perform spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point.

[0070] In some possible implementations, the device may further include a first signal generator 7 and a second signal generator 8, wherein the first signal generator is configured to output sinusoidal signals f1 and f2, where f2 is a k-order harmonic signal of f1 and the phase difference between the two is 0; and the phase modulator is driven by the sinusoidal signals f1 and f2;

[0071] The double-sideband modulated signal is:

[0072] E u =A u exp(i2πf c t+iβ1sin(2πf1t+φ1)+iβ2sin(2πf2t+φ2));#

[0073] Among them, E u is a double-sideband modulated signal, f c is the optical carrier frequency, A u is the optical carrier amplitude, modulation depth β1=πV1 / V π1 , β2=πV2 / V π2 , with the modulation signal amplitude V1, V2, and the modulator half-wave voltage V π1 , V π2 is related to the size of , i represents the imaginary unit, φ1 and φ2 are the initial phases of the modulation signal.

[0074] The second signal generator is used to output a sinusoidal signal f3, and use the sinusoidal signal f3 to drive the acousto-optic frequency shifter;

[0075] The optical carrier frequency shift signal is:

[0076] E d =A d exp(i2πf c t+i2πf3t);

[0077] Among them, A d Indicates the amplitude of the signal, E d Indicates the optical carrier frequency shift signal.

[0078] In some possible implementations, the ADC acquisition clock of the photoelectric balance detection system is synchronized with the clocks of the first and second signal generators. This clock synchronization ensures that the signal is sampled at a precise time. If the clocks are not synchronized, the sampling point may deviate from the actual position of the signal, resulting in sampling errors and affecting the accuracy of signal analysis.

[0079] In some possible implementations, the upper and lower optical signals are input to the balanced detector input port of the photoelectric balanced detection system through a beam combiner, and the beat frequency generates an electrical signal (i.e., interference waveform data) for output:

[0080]

[0081] Among them, J p(q) (·) represents the first kind of p(q) order Bessel function, and R(f)=G(f)exp(iφ(f)) represents the frequency response characteristics of the photoelectric balanced detection sampling system.

[0082] Since f2 is the kth order harmonic component of f1, f2 = kf1, φ2 = kφ1, and the DC component is ignored, the above formula can be further simplified as follows:

[0083]

[0084] exp(i2πf3t+i(p+k·q)(2πf1t+φ1)+iφ(f3+(p+k·q)f1))

[0085] In some possible implementations, the phase information at the preset frequency point is the phase information at the frequency point f3+nf1:

[0086] Φ(f3+nf1)=n(2πf1t+φ1)+φ(f3+nf1).

[0087] Specifically, the processor is used to:

[0088] Performing spectrum analysis on the interference waveform data to obtain spectrum analysis data, and determining phase information corresponding to peak point data of the spectrum analysis data;

[0089] The phase information is unwrapped and the first-order linear phase is removed to obtain the residual phase, wherein the residual phase is used to characterize the additional phase characteristics of the photoelectric balance detection system.

[0090] Exemplarily, the interference waveform data is subjected to spectrum analysis to obtain Figure 2The spectrum analysis results shown in the figure select the phase information corresponding to the peak point data, Φ(f3+nf1); unwrap the selected phase information, remove the phase 2π cycle jump, and obtain the corrected unfolded phase data Φ′(f3+nf1); fit the first-order slope of the phase / frequency curve in the frequency range of 0.6MHz to 51MHz, remove the first-order linear phase to obtain the residual phase φ(f3+nf1). The phase of the light source modulation sideband is linearly related, which is equivalent to the constant delay added to the single measurement system. It can be deducted by fitting the first-order linear term of the phase curve / frequency curve, and then the residual phase reflects the additional phase characteristics of the system to be measured, and finally the following is obtained: Figure 3 The phase characteristic measurement results of the photoelectric balanced detection sampling system are shown.

[0091] Exemplarily, the photoelectric balanced detection sampling system may include: a photoelectric balanced detector, a self-made anti-aliasing low-pass filter, and a high-speed oscilloscope R&S RTM3004 (analog acquisition card);

[0092] The first signal generator output frequency f1 = 900 kHz, the 10th-order harmonic frequency f2 = 9 MHz, and φ1 = φ2 = 0°. The second signal generator output frequency f3 = 51 MHz. The combined optical signal is fed to a photoelectric balanced detector. The output electrical signal is shaped by a custom anti-aliasing low-pass filter and sampled by an oscilloscope with a sampling rate of 625 MS / s and 200k sampling points. During testing, the oscilloscope's 10 MHz synchronization output is connected to the synchronization input ports of the first and second signal generators to ensure clock synchronization between the three.

[0093] The present application discloses a phase characteristic measurement device for a photoelectric balance detection system, comprising:

[0094] Narrow linewidth lasers, beam splitters, phase modulators, acousto-optic frequency shifters, beam combiners, and processors;

[0095] The narrow linewidth laser is used to output an optical signal and output the optical signal through a beam splitter as two optical signals, one up and one down. The phase modulator is used to receive the optical signal of the up branch and generate a double-sideband modulated signal. The acousto-optic frequency shifter is used to receive the optical signal of the down branch and perform optical carrier frequency shifting to generate an optical carrier frequency-shifted signal. The beam combiner is used to interfere with the double-sideband modulated signal and the optical carrier frequency-shifted signal and input them into the photoelectric balance detection system. The processor is used to obtain sampled interference waveform data of the photoelectric balance detection system and perform spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point. Electro-optical modulation is used to generate multiple phase-correlated optical frequency sidebands, which are detected by the photoelectric balance detection system and collected. After being processed by the processor and subjected to spectrum analysis, phase information reflecting the additional phase characteristics of the photoelectric balance detection system can be obtained. In this way, the modulated optical signal passes through the signal receiving chain of the photoelectric balance detection system completely, avoiding the measurement error caused by the cascade matching of each component and eliminating the need to disassemble and test each component, thereby reducing the complexity of the phase characteristic measurement of the entire system.

[0096] The above are some specific implementations of the phase characteristic measurement device of the photoelectric balance detection system provided in the embodiments of this application. Based on this, this application also provides a corresponding method. The method provided in the embodiments of this application will be introduced below, and this method and the device described above can be referenced in correspondence with each other.

[0097] Figure 4 A flow chart of a method for measuring phase characteristics of a photoelectric balance detection system provided by an embodiment of the present invention is referred to as a specific embodiment 2. Figure 4 The method may include:

[0098] S401: The narrow linewidth laser outputs an optical signal and outputs the optical signal as two optical signals, one above and one below, through a beam splitter.

[0099] S402: The phase modulator receives the optical signal of the add branch and generates a double-sideband modulated signal. The acousto-optic frequency shifter receives the optical signal of the drop branch and performs optical carrier frequency shifting to generate an optical carrier frequency-shifted signal.

[0100] S403: The beam combiner interferes the double-sideband modulated signal and the optical carrier frequency-shifted signal, and inputs the interference into the photoelectric balance detection system.

[0101] S404: The processor obtains sampled interference waveform data of the photoelectric balance detection system, and performs spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point.

[0102] Optionally, the acquiring of sampled interference waveform data of the photoelectric balance detection system and performing spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point includes:

[0103] Performing spectrum analysis on the interference waveform data to obtain spectrum analysis data;

[0104] Determining phase information corresponding to peak point data of the spectrum analysis data;

[0105] The phase information is unwrapped and the first-order linear phase is removed to obtain a residual phase, and the residual phase is used to characterize the additional phase characteristics of the photoelectric balance detection system.

[0106] Optionally, the method further includes:

[0107] The first signal generator is used to output sinusoidal signals f1 and f2, where f2 is a k-order harmonic signal of f1 and the phase difference between the two is 0; the sinusoidal signals f1 and f2 are used to drive the phase modulator;

[0108] The double-sideband modulated signal is:

[0109] E u =A u exp(i2πf c t+iβ1sin(2πf1t+φ1)+iβ2sin(2πf2t+φ2));#

[0110] Among them, E u is a double-sideband modulated signal, f c is the optical carrier frequency, A u is the optical carrier amplitude, modulation depth β1=πV1 / V π1 , β2=πV2 / V π2 , with the modulation signal amplitude V1, V2, and the modulator half-wave voltage V π1 , V π2 is related to the size of , i represents the imaginary unit, φ1 and φ2 are the initial phases of the modulation signal.

[0111] Optionally, the method further includes: a second signal generator configured to output a sinusoidal signal f3, and utilizing the sinusoidal signal f3 to drive the acousto-optic frequency shifter;

[0112] The optical carrier frequency shift signal is:

[0113] E d =A d exp(i2πf c t+i2πf3t);

[0114] Among them, A d Indicates the amplitude of the signal, E d Indicates the optical carrier frequency shift signal.

[0115] Optionally, the interference waveform data is:

[0116]

[0117] Among them, J p(q) (·) represents the first kind of p(q) order Bessel function, and R(f)=G(f)exp(iφ(f)) represents the frequency response characteristics of the photoelectric balanced detection sampling system.

[0118] Optionally, the phase information at the preset frequency point is the phase information at the frequency point f3+nf1:

[0119] Φ(f3+nf1)=n(2πf1t+φ1)+φ(f3+nf1).

[0120] The embodiments of the present application also provide a computer storage medium for implementing the solutions provided in the embodiments of the present application.

[0121] The computer storage medium stores code, and when the code is executed, the device executing the code implements the method described in the second embodiment of the present application.

[0122] The "first" and "second" in the names such as "first" and "second" (if any) mentioned in the embodiments of this application are only used as name identifiers and do not represent the first or second in order.

[0123] Through the description of the above implementation methods, it can be known that those skilled in the art can clearly understand that all or part of the steps in the above embodiment methods can be implemented by means of software plus a general hardware platform. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a read-only memory (ROM) / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the method described in Example 2 of the present application or some parts of the embodiment.

[0124] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the method embodiment, since it is basically similar to the device embodiment, the description is relatively simple. For the relevant parts, refer to the partial description of the device embodiment. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment scheme. Those of ordinary skill in the art can understand and implement it without paying any creative work.

[0125] The above description is merely an exemplary embodiment of the present application and is not intended to limit the scope of protection of the present application.

Claims

1. A phase characteristic measurement device for a photoelectric balance detection system, characterized in that: include: Narrow linewidth lasers, beam splitters, phase modulators, acousto-optic frequency shifters, beam combiners, and processors; The narrow linewidth laser is used to output an optical signal and output the optical signal as two optical signals, upper and lower, through a beam splitter; The phase modulator is used to receive the optical signal of the add branch and generate a double-sideband modulated signal. The acousto-optic frequency shifter is used to receive the optical signal of the drop branch and perform optical carrier frequency shift to generate an optical carrier frequency-shifted signal. The beam combiner is used to interfere the double-sideband modulated signal and the optical carrier frequency-shifted signal, and input the interference into the photoelectric balance detection system; The processor is used to obtain sampled interference waveform data of the photoelectric balance detection system, and perform spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point.

2. The device according to claim 1, characterized in that The device also includes a first signal generator; The first signal generator is used to output sinusoidal signals f1 and f2, where f2 is a k-order harmonic signal of f1 and the phase difference between the two is 0; the sinusoidal signals f1 and f2 are used to drive the phase modulator; The double-sideband modulated signal is: E u =A u exp(i2πf c t+iβ1sin(2πf1t+φ1)+iβ2sin(2πf2t+φ2));# Among them, E u is a double-sideband modulated signal, f c is the optical carrier frequency, A u is the optical carrier amplitude, modulation depth β1=πV1 / V π1 , β2=πV2 / V π2 , with the modulation signal amplitude V1, V2, and the modulator half-wave voltage V π1 , V π2 is related to the size of , i represents the imaginary unit, φ1 and φ2 are the initial phases of the modulation signal.

3. The device according to claim 1, characterized in that The device also includes a second signal generator; The second signal generator is used to output a sinusoidal signal f3, and the sinusoidal signal f3 is used to drive the acousto-optic frequency shifter; The optical carrier frequency shift signal is: E d =A d exp(i2πf c t+i2πf3t); Among them, A d Indicates the amplitude of the signal, E d Indicates the optical carrier frequency shift signal.

4. The device according to claim 1, characterized in that The interference waveform data is: Among them, J p(q) (·) represents the first kind of p(q) order Bessel function, and R(f)=G(f)exp(iφ(f)) represents the frequency response characteristics of the photoelectric balanced detection sampling system.

5. The device according to claim 1, characterized in that The phase information at the preset frequency point is the phase information at the frequency point f3+nf1: Φ(f3+nf1)=n(2πf1t+φ1)+φ(f3+nf1).

6. The device according to claim 1, characterized in that The processor is specifically configured to: Performing spectrum analysis on the interference waveform data to obtain spectrum analysis data; Determining phase information corresponding to peak point data of the spectrum analysis data; The phase information is unwrapped and the first-order linear phase is removed to obtain a residual phase, and the residual phase is used to characterize the additional phase characteristics of the photoelectric balance detection system.

7. A method for measuring the phase characteristics of a photoelectric balance detection system, characterized in that: include: The narrow linewidth laser outputs an optical signal and outputs the optical signal through a beam splitter to output upper and lower optical signals; The phase modulator receives the optical signal of the add branch and generates a double-sideband modulated signal. The acousto-optic frequency shifter receives the optical signal of the drop branch and performs optical carrier frequency shifting to generate an optical carrier frequency-shifted signal. The beam combiner interferes the double-sideband modulated signal and the optical carrier frequency-shifted signal and inputs the interference into the photoelectric balance detection system; The processor obtains sampled interference waveform data of the photoelectric balance detection system, and performs spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point.

8. The method according to claim 7, characterized in that The acquiring of sampled interference waveform data of the photoelectric balance detection system and performing spectrum analysis on the interference waveform data to obtain phase information at a preset frequency point includes: Performing spectrum analysis on the interference waveform data to obtain spectrum analysis data; Determining phase information corresponding to peak point data of the spectrum analysis data; The phase information is unwrapped and the first-order linear phase is removed to obtain a residual phase, and the residual phase is used to characterize the additional phase characteristics of the photoelectric balance detection system.

9. The method according to claim 6, characterized in that The method further comprises: The first signal generator is used to output sinusoidal signals f1 and f2, and use the sinusoidal signals f1 and f2 to drive the phase modulator; The double-sideband modulated signal is: E u =A u exp(i2πf c t+iβ1sin(2πf1t+φ1)+iβ2sin(2πf2t+φ2));# Among them, E u is a double-sideband modulated signal, f c is the optical carrier frequency, A u is the optical carrier amplitude, modulation depth β1=πV1 / V π1 , β2=πV2 / V π2 , with the modulation signal amplitude V1, V2, and the modulator half-wave voltage V π1 , V π2 is related to the size of , i represents the imaginary unit, φ1 and φ2 are the initial phases of the modulation signal.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the phase characteristic measurement method of the photoelectric balance detection system according to claims 6 to 9 is implemented.

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