Laser phase noise undersampling measurement method, device, medium and product

Abstract

The present application discloses a laser phase noise undersampling measurement method, equipment, medium and product, and relates to the field of coherent synthesis technology. The method comprises: determining the minimum number of integration points of a down-sampled signal based on the modulation frequency and sampling rate of the down-sampled signal; performing I / Q modulation on a voltage signal based on a time signal and a modulation frequency to obtain a first modulation signal and a second modulation signal; integrating the first modulation signal and the second modulation signal respectively based on the minimum number of integration points to obtain a first modulation integral signal and a second modulation integral signal, and then determining a single-cycle phase recovery value; completing phase unwrapping based on the single-cycle phase recovery value to complete full-cycle phase recovery. The present application utilizes an integral adjustment method to complete phase noise measurement under the condition of undersampling and without losing measurement accuracy, thereby reducing the requirements for data storage and calculation.

Description

Technical Field

[0001] The present application relates to the field of coherent synthesis technology, and in particular to a laser phase noise undersampling measurement method, equipment, medium and product. Background Art

[0002] Coherent combining technology can maintain beam quality while increasing laser power, and is an effective technical path to break through the single-aperture output power limit of high-energy lasers. Coherent combining requires the phase synchronization of each laser. However, due to factors such as thermal effects, mechanical vibrations, airflow disturbances, and power supply noise, the laser phase is constantly changing, and active phase control methods are usually required to correct phase noise. Accurately measuring and characterizing laser phase noise and obtaining the phase noise spectrum distribution can, on the one hand, suppress it from the perspective of the noise source, and on the other hand, deduce the bandwidth requirements of the phase control algorithm based on the measurement results, which is of great significance to the design and implementation of coherent combining systems.

[0003] In the field of coherent synthesis, there are three main methods for measuring phase noise: heterodyne, homodyne and dithering. Homodyne and dithering methods can only measure the sine (or cosine) of the phase and cannot directly recover the phase. In contrast, the heterodyne method can obtain the sine and cosine of the phase at the same time, and can obtain a unique phase value in a single cycle. It can further track the phase change in any range by unwinding, which is the preferred solution for phase measurement. In the heterodyne method, an acousto-optic modulator (AOM) is required, and its modulation frequency is usually in the order of 100MHz. It is necessary to collect data and recover the phase of the signal at this frequency, which requires a higher sampling rate. However, the phase noise characterization in the 100kHz frequency range is sufficient to cover the application requirements of coherent synthesis. The high sampling rate will bring about problems such as data redundancy, large amount of calculation and high hardware requirements. Especially for offline measurement methods, in order to more accurately characterize the low-frequency components, it is necessary to collect data over a longer time range. The storage capacity of the measuring instrument is limited, and the sampling rate needs to be reduced to meet the time requirement, thereby limiting the scope of application. Summary of the invention

[0004] The purpose of this application is to provide a laser phase noise undersampling measurement method, equipment, medium and product, which can complete phase noise measurement under the conditions of undersampling and without losing measurement accuracy, thereby reducing data storage and calculation requirements.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a laser phase noise undersampling measurement method, which is applied to an experimental optical path structure, wherein the experimental optical path structure includes: a seed laser, a beam splitter, an amplifier, an acousto-optic modulator, a signal generator, a beam combiner, a light detector, and an oscilloscope;

[0007] The seed laser is used to emit a seed laser;

[0008] The beam splitter is arranged on the output optical path of the seed laser; the seed laser splits the seed laser to obtain a first light beam and a second light beam;

[0009] The amplifier is arranged on the output optical path of the first light beam of the beam splitter; the amplifier is used to amplify the first light beam to obtain a test light beam;

[0010] The acousto-optic modulator is arranged on the output optical path of the second light beam of the beam splitter; the acousto-optic modulator is also connected to the signal generator; the acousto-optic modulator is used to modulate the second light beam based on the output signal of the signal generator to generate a reference light beam;

[0011] The beam combiner is arranged on the output optical path of the amplifier; the beam combiner is also arranged on the output optical path of the acousto-optic modulator; the beam combiner is used to combine the test beam and the reference beam to obtain a composite beam;

[0012] The optical detector is arranged on the output optical path of the beam combiner; the optical detector is used to obtain the beat frequency signal;

[0013] The oscilloscope is connected to the photodetector; the oscilloscope is used to perform waveform detection on the beat frequency signal and perform down-sampling processing on the beat frequency signal to obtain a down-sampled signal;

[0014] The laser phase noise undersampling measurement method comprises:

[0015] Acquire a down-sampling signal; the down-sampling signal includes a time signal and a voltage signal;

[0016] Determining a minimum number of integration points of the down-sampled signal based on a modulation frequency and a sampling rate of the down-sampled signal;

[0017] Based on the time signal and the modulation frequency, I / Q modulate the voltage signal to obtain a first modulation signal and a second modulation signal;

[0018] Integrate the first modulated signal based on the minimum number of integration points to obtain a first modulated integrated signal;

[0019] Integrate the second modulated signal based on the minimum number of integration points to obtain a second modulated integrated signal;

[0020] Determining a single-cycle phase recovery value based on the first modulated integrated signal and the second modulated integrated signal;

[0021] Phase unwrapping is performed based on the single-cycle phase recovery value to complete the full-cycle phase recovery.

[0022] Optionally, determining the minimum number of integration points of the down-sampled signal based on the modulation frequency and the sampling rate of the down-sampled signal comprises:

[0023] Determining a ratio of the modulation frequency to the sampling rate as an intermediate quantity; the intermediate quantity is a non-integer;

[0024] Determine a plurality of to-be-determined integral points; the product of any of the to-be-determined integral points and the intermediate amount is an integer;

[0025] Determine the minimum value among the pending integral points as the minimum integral point.

[0026] Optionally, the first modulation signal is:

[0027] ;

[0028] in, is the first modulation signal, is the voltage signal, is the modulation frequency, For the time signal.

[0029] Optionally, the second modulation signal is:

[0030] ;

[0031] in, is the second modulation signal.

[0032] Optionally, the first modulated integral signal is:

[0033] ;

[0034] in, is the first modulated integral signal, is the integration time.

[0035] Optionally, the second modulated integral signal is:

[0036] ;

[0037] in, is the second modulated integrated signal.

[0038] Optionally, the single-cycle phase recovery value is:

[0039] ;

[0040] in, is the single-cycle phase recovery value, angle(*) is the angle function, Is an imaginary unit.

[0041] In a second aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned laser phase noise undersampling measurement method.

[0042] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the above-mentioned laser phase noise undersampling measurement method when executed by a processor.

[0043] In a fourth aspect, the present application provides a computer program product, including a computer program, which implements the above-mentioned laser phase noise undersampling measurement method when executed by a processor.

[0044] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0045] The present application provides a laser phase noise undersampling measurement method, equipment, medium and product. Compared with the traditional heterodyne phase noise measurement method, the measurement can be completed using a low-bandwidth oscilloscope, with low sampling rate requirements. While reducing equipment costs, the low-frequency characterization range is more suitable for coherent synthesis application requirements and solves the data redundancy problem of traditional solutions. In addition, the present application uses an integral demodulation method for phase compensation, with simple parameters and small calculation amount, and has better robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 paying creative work.

[0047] Figure 1 This is a diagram of an experimental optical path structure in an embodiment of the present application;

[0048] Figure 2 This is a flow chart of a laser phase noise undersampling measurement method in one embodiment of the present application;

[0049] Figure 3 This is a schematic diagram of a laser phase noise undersampling measurement method in one embodiment of the present application;

[0050] Figure 4This is a comparison diagram of time domain measurement results of the integral demodulation method (this method) and the low-pass filtering method (traditional method) when the noise to be measured is white noise in an embodiment of the present application;

[0051] Figure 5 This is a comparison diagram of spectrum measurement results of the integral demodulation method (this method) and the low-pass filtering method (traditional method) when the noise to be measured is white noise in an embodiment of the present application;

[0052] Figure 6 This is a comparison diagram of time domain measurement results of the integral demodulation method (this method) and the low-pass filtering method (traditional method) when the noise to be measured is pink noise in an embodiment of the present application;

[0053] Figure 7 This is a comparison diagram of spectrum measurement results of the integral demodulation method (this method) and the low-pass filtering method (traditional method) when the noise to be measured is pink noise in an embodiment of the present application;

[0054] Figure 8 For comparison of time domain measurement results of undersampling at different frequencies when the noise to be measured is white noise in one embodiment of the present application;

[0055] Fig. 9 For comparison of spectrum measurement results of different frequency undersampling when the noise to be measured is white noise in one embodiment of the present application;

[0056] Fig.10 A comparison of time domain measurement results of undersampling at different frequencies in an embodiment of the present application (experimental results);

[0057] Fig.11 A comparison of spectrum measurement results of different frequency undersampling in an embodiment of the present application (experimental results);

[0058] Fig.12 A comparison of the time domain measurement results when the laser to be measured is artificially disturbed and when it is not disturbed in one embodiment of the present application (experimental results);

[0059] Fig.13 The comparison of the spectrum measurement results when the laser to be measured is artificially disturbed and when it is not disturbed in one embodiment of the present application (experimental results);

[0060] Fig.14 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0062] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0063] In an exemplary embodiment, a laser phase noise undersampling measurement method is applied to an experimental optical path structure, such as Figure 1 As shown, the experimental optical path structure includes: a seed laser, a beam splitter, an amplifier, an acousto-optic modulator, a signal generator, a beam combiner, a light detector and an oscilloscope. The seed laser is used to emit a seed laser. The beam splitter is arranged on the output optical path of the seed laser. The seed laser splits the seed laser to obtain a first light beam and a second light beam. The amplifier is arranged on the output optical path of the first light beam of the beam splitter. The amplifier is used to amplify the first light beam to obtain a test light beam. The acousto-optic modulator is arranged on the output optical path of the second light beam of the beam splitter. The acousto-optic modulator is also connected to the signal generator. The acousto-optic modulator is used to modulate the second light beam based on the output signal of the signal generator to generate a reference light beam. The beam combiner is arranged on the output optical path of the amplifier. The beam combiner is also arranged on the output optical path of the acousto-optic modulator. The beam combiner is used to combine the test light beam and the reference light beam to obtain a composite light beam. The light detector is arranged on the output optical path of the beam combiner. The light detector is used to obtain a beat frequency signal. The oscilloscope is connected to the light detector. The oscilloscope is used to perform waveform detection on the beat frequency signal and perform down-sampling processing on the beat frequency signal to obtain a down-sampled signal.

[0064] The seed laser is divided into two beams by a beam splitter. One beam passes through the laser amplifier to be tested, and the other beam passes through the acousto-optic modulator and undergoes frequency shift as a reference beam. The two beams are then synthesized by a beam combiner. Due to the difference in center frequency, a heterodyne beat frequency is generated. The beat frequency signal is detected by a photodetector (PD), and finally an oscilloscope is used for waveform monitoring and data acquisition. The experimental optical path structure is the general optical path structure of the heterodyne method. "Sampling" is not a special action, but the selection of the sampling rate is involved when storing the signal data of the photodetector.

[0065] In order to ensure the effectiveness of the undersampling method, the experimental parameter setting needs to meet a basic condition: the modulation frequency f m Divide by the sampling rate f s cannot be an integer n (i.e. fm / f s ≠n), in actual operation, the sampling rate of the oscilloscope can be selected from a limited set, and the modulation frequency of the AOM can be set by the signal generator, but it is required to be within its operating frequency range. It is determined by the actual operating frequency and bandwidth of the AOM. For example, there are 80MHz, 100MHz, 110MHz AOMs, and the bandwidth is unknown. Among them, the modulation frequency refers to the frequency of the modulation signal acting on the AOM, which is set by the signal generator. The sampling rate is set by the oscilloscope and is a parameter for data storage.

[0066] The sampling rate selection of the oscilloscope is related to the actual oscilloscope product model, but the sampling rate cannot be adjusted arbitrarily, usually 250MHz, 62.5MHz, 10MHz, etc. Generally speaking, there is no lower limit to the sampling rate, but there is an upper limit, which depends on the bandwidth of the oscilloscope.

[0067] like Figure 2 , the laser phase noise undersampling measurement method includes:

[0068] Step 201: Acquire a down-sampled signal. The down-sampled signal includes a time signal and a voltage signal.

[0069] Step 202: Based on the modulation frequency and sampling rate of the down-sampled signal, determine the minimum number of integration points of the down-sampled signal. Determine that the ratio of the modulation frequency to the sampling rate is an intermediate quantity. The intermediate quantity is a non-integer. Determine multiple numbers of integration points to be determined. The product of any number of integration points to be determined and the intermediate quantity is an integer. Determine the minimum value among the number of integration points to be determined as the minimum number of integration points. Since the data is discrete, there is a corresponding relationship between the number of integration points and the integration time: dt=1 / fs, τ=Ντdt=Ντ / fs. The number of integration points is used in the integral demodulation step.

[0070] Step 203: Based on the time signal and the modulation frequency, perform I / Q modulation on the voltage signal to obtain a first modulation signal and a second modulation signal. The first modulation signal is:

[0071] .

[0072] in, is the first modulation signal, is the voltage signal, is the modulation frequency, For the time signal.

[0073] The second modulation signal is:

[0074] .

[0075] in, is the second modulation signal.

[0076] Step 204: Integrate the first modulated signal based on the minimum number of integration points to obtain a first modulated integrated signal. The first modulated integrated signal is:

[0077] .

[0078] in, is the first modulated integral signal, is the integration time.

[0079] Step 205: Integrate the second modulated signal based on the minimum integration point number to obtain a second modulated integrated signal. The second modulated integrated signal is:

[0080] .

[0081] in, is the second modulated integrated signal.

[0082] Step 206: Determine a single-cycle phase recovery value based on the first modulated integral signal and the second modulated integral signal. The single-cycle phase recovery value is:

[0083] .

[0084] in, is the single-cycle phase recovery value, angle(*) is the angle function, Is an imaginary unit.

[0085] Step 207: Complete phase unwrapping based on the single-cycle phase recovery value to complete full-cycle phase recovery.

[0086] Heterodyne phase measurement requires processing of experimental data before obtaining the phase. "Undersampling" refers to the process of data acquisition and processing. According to the sampling law, the sampling rate should be greater than twice the signal frequency to fully recover the signal. The undersampling method does not have this requirement. After completing data acquisition, the experimental data needs to be imported into mathematical calculation software for processing. The processing flow is as follows: Figure 3 shown.

[0087] Step 1: Input data time data t and voltage data V, modulation frequency f m . Sampling rate f s It is the reciprocal of the time interval and can be directly obtained from the time data t. Note that to ensure the corresponding relationship between the data, the time data t and the voltage data V are at the modulation frequency f m Collected below.

[0088] Step 2: Calculate the minimum integral points. The integral points are integers. Through the loop statement, find the minimum integral points that satisfy the formula N. τ f m / f s =N multiple undetermined integral points , n is an integer, and the minimum value is selected as the minimum integral points N.

[0089] Step 3: Perform I / Q modulation on the data. According to the input data t, V, f m , perform I / Q modulation on V, and obtain I(t)=Vcos(2π f m t), Q(t)=Vsin(2π f m t).

[0090] Step 4: Integrate the modulated data. According to the first modulation signal I(t) and the second modulation signal Q(t), integrate to obtain a first modulation integral signal I' and a second modulation integral signal Q'.

[0091] Step 5: Restore the phase. The second modulated integral signal Q' is proportional to the cosine function cos(Δφ) of the phase difference, and the first modulated integral signal I' is proportional to the sine function -sin(Δφ) of the phase difference, so the phase can be obtained by the angle function, Δφ=angle(I'-iQ').

[0092] Step 6: Phase unwrapping. The phase calculated by the angle function angle is only within one cycle [-π, π], while the actual phase noise may change within multiple phase cycles. The unwrapping operation is required to track the continuous change of the phase.

[0093] First, the scheme of the application was simulated and verified under the condition of normal sampling rate. The AOM modulation frequency was 100MHz and the sampling rate was 250MHz. The frequency-cutoff white noise and 1 / f noise were generated by simulation respectively. The phase demodulation was performed using the integral method. The results Figures 4 to 7 As shown. Under the two noise models, the measured results are almost completely consistent with the actual phase noise, and the time domain curve and spectrum can overlap well. By calculating the standard deviation of the phase noise, a more quantitative analysis can be performed. The calculation results show that the relative deviation between the measured noise standard deviation and the actual standard deviation (the absolute value of the difference between the two standard deviations divided by the true standard deviation) is very small, 0.052% and 0.015% respectively, which quantitatively illustrates the accuracy of the test method.

[0094] Then, the method was verified under undersampling conditions, with sampling rates of 125MHz, 62.5MHz, and 31.25MHz. The results are shown in Figures 8 to 9 As shown, the time domain phase noise curve is vertically shifted for easy comparison. It can be seen that when the sampling rate is lower than twice the signal frequency, the phase noise can still be correctly obtained using the method mentioned in this application. After calculation, the relative deviations of the standard deviation of the measured results and the true standard deviation are 0.0013%, 0.0023% and 0.0056% respectively, which proves the accuracy and effectiveness of the undersampling method.

[0095] In the experimental environment, a test platform was built according to the above measurement optical path structure, and the phase noise generated by a 10m long optical fiber was tested. The same test data was downsampled and the results obtained at different sampling rates are as follows: Figure 10-11 As shown, for data with different sampling rates, the method of the present application can calculate the same phase noise result, and the time domain curve and the spectrum can accurately correspond, which experimentally proves the effectiveness of the method.

[0096] In order to more intuitively compare the sensitivity of the method to phase noise, the 10m long optical fiber to be tested was artificially disturbed in the experiment (using a hair dryer to blow on the optical fiber) and compared with the results under normal conditions. The results are as follows: Figure 12-13 As shown. Combined Figure 10-11 It can be clearly seen that the phase variation range in the initial quiet environment is only a few tenths of radians, and the variation range is expanded to tens of radians under the action of the hair dryer. The difference can be clearly seen from the time domain and frequency domain results of the phase noise under the two conditions, indicating that the method has a good response capability to small and large phase changes.

[0097] In addition to measuring the phase noise of the laser amplifier, the optical path to be tested can be a variety of optical path structures under a variety of environmental conditions, and the test results represent the phase noise generated by a specific optical path structure under specific environmental conditions. For example, a section of optical fiber is connected to the test path, and the environmental condition is forced mechanical vibration. The phase noise measured by the method of the present application is the phase noise generated by the optical fiber under the vibration condition. In addition to the optical fiber waveguide structure, the test optical path can also adopt a spatial structure, or a combination of spatial and waveguide structures. After the two lasers are collimated and emitted in space, they are synthesized by a beam combining device, and detection and data acquisition are performed in the same way. The data acquisition equipment is not limited to oscilloscopes, and other equipment that can communicate with the PD and has storage functions can be used.

[0098] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig.14As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a laser phase noise undersampling measurement method is implemented.

[0099] Those skilled in the art will understand that Fig.14 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0100] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0101] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0102] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0103] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0104] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0105] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A laser phase noise undersampling measurement method, characterized in that: The laser phase noise undersampling measurement method is applied to an experimental optical path structure, which includes: a seed laser, a beam splitter, an amplifier, an acousto-optic modulator, a signal generator, a beam combiner, a light detector and an oscilloscope; The seed laser is used to emit a seed laser; The beam splitter is arranged on the output optical path of the seed laser; the seed laser splits the seed laser to obtain a first light beam and a second light beam; The amplifier is arranged on the output optical path of the first light beam of the beam splitter; the amplifier is used to amplify the first light beam to obtain a test light beam; The acousto-optic modulator is arranged on the output optical path of the second light beam of the beam splitter; the acousto-optic modulator is also connected to the signal generator; the acousto-optic modulator is used to modulate the second light beam based on the output signal of the signal generator to generate a reference light beam; The beam combiner is arranged on the output optical path of the amplifier; the beam combiner is also arranged on the output optical path of the acousto-optic modulator; the beam combiner is used to combine the test beam and the reference beam to obtain a composite beam; The optical detector is arranged on the output optical path of the beam combiner; the optical detector is used to obtain the beat frequency signal; The oscilloscope is connected to the photodetector; the oscilloscope is used to perform waveform detection on the beat frequency signal and perform down-sampling processing on the beat frequency signal to obtain a down-sampled signal; The laser phase noise undersampling measurement method comprises: Acquire a down-sampling signal; the down-sampling signal includes a time signal and a voltage signal; Determining a minimum number of integration points of the down-sampled signal based on a modulation frequency and a sampling rate of the down-sampled signal; Based on the time signal and the modulation frequency, I / Q modulate the voltage signal to obtain a first modulation signal and a second modulation signal; Integrate the first modulated signal based on the minimum number of integration points to obtain a first modulated integrated signal; Integrate the second modulated signal based on the minimum number of integration points to obtain a second modulated integrated signal; Determining a single-cycle phase recovery value based on the first modulated integrated signal and the second modulated integrated signal; Phase unwrapping is performed based on the single-cycle phase recovery value to complete the full-cycle phase recovery.

2. The laser phase noise undersampling measurement method according to claim 1, characterized in that: Determining a minimum number of integration points of the down-sampled signal based on a modulation frequency and a sampling rate of the down-sampled signal includes: Determining a ratio of the modulation frequency to the sampling rate as an intermediate quantity; the intermediate quantity is a non-integer; Determine a plurality of to-be-determined integral points; the product of any of the to-be-determined integral points and the intermediate amount is an integer; Determine the minimum value among the pending integral points as the minimum integral point.

3. The laser phase noise undersampling measurement method according to claim 1, characterized in that: The first modulation signal is: ； in, is the first modulation signal, is the voltage signal, is the modulation frequency, For the time signal.

4. The laser phase noise undersampling measurement method according to claim 3, characterized in that: The second modulation signal is: ； in, is the second modulation signal.

5. The laser phase noise undersampling measurement method according to claim 4, characterized in that: The first modulated integral signal is: ； in, is the first modulated integral signal, is the integration time.

6. The laser phase noise undersampling measurement method according to claim 5, characterized in that: The second modulation integral signal is: ； in, is the second modulated integrated signal.

7. The laser phase noise undersampling measurement method according to claim 6, characterized in that: The single cycle phase recovery value is: ； in, is the single-cycle phase recovery value, angle(*) is the angle function, Is an imaginary unit.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the laser phase noise undersampling measurement method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the laser phase noise undersampling measurement method according to any one of claims 1 to 7 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the laser phase noise undersampling measurement method according to any one of claims 1 to 7 is implemented.

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