A device and method for measuring phase parameters of fiber optic modulation format signals

Abstract

This invention discloses a device and method for measuring the phase parameters of fiber optic modulated signals. The device includes a pump module, a depolarization module, a signal input module, a wavelength splitting module, a detection module, a phase parameter extraction module, and a control and data processing module. The pump module generates a tunable dual-pump signal. Based on the fiber stimulated Brillouin effect, the phase difference between two adjacent wavelengths of the signal under test is obtained using dual-stimulated Brillouin frequency-selective amplification and beat frequency coherence. By changing the wavelength of the dual-pump signal, the phase differences between two adjacent wavelengths at a series of different wavelength positions are obtained. By accumulating these phase differences and using the dual-pump signal as a phase reference signal, the relative and absolute phase parameters of the fiber optic modulated signal are obtained. This invention employs dual-stimulated Brillouin frequency-selective amplification and beat frequency coherence phase parameter measurement technology to achieve accurate measurement of wavelength-related phase parameters with wavelength resolution at the pM level.

Description

Technical Field

[0001] This invention relates to the field of optical communication signal parameter measurement technology, and in particular to a device and method for measuring phase parameters of fiber optic modulation format signals. Background Technology

[0002] In the internet age, the traffic of backbone fiber optic communication networks is growing at a rate of 50% to 80% annually, while internet traffic, in certain phases such as with 5G and the Internet of Things (IoT), will experience tenfold or even hundredfold growth. This necessitates that existing fiber optic communication networks be able to transmit larger amounts of data at higher speeds. Facing the challenges posed by this trend, improving the spectral efficiency of existing fiber optic communication networks to find new and more efficient available bandwidth to meet the ever-increasing data communication volume has become a research hotspot.

[0003] Higher data demands require optical fiber communication network systems to have higher single-wavelength capacity and higher spectral efficiency. Therefore, increasing the number of subcarriers is crucial, leading to smaller frequency spacing between adjacent channels. Based on these requirements, advanced optical modulation formats, with their higher spectral efficiency, particularly high-spectral-efficiency multicarrier transmission technologies, where the subcarrier frequency spacing equals the symbol rate per subcarrier, have become promising solutions for further improving system robustness and spectral efficiency. In existing technologies, modulation formats such as Dense Wavelength Division Multiplexing (DWDM) and Coherenet Wavelength Division Multiplexing (CoWDM) have been developed based on existing Wavelength Division Multiplexing (WDM) systems. Subsequently, research and application of novel optical modulation formats that utilize the amplitude and phase of optical signals to carry signals have been conducted, such as Binary Phase Shift Keying (BPSK) and Quadrature Amplitude Modulation (QAM).

[0004] Spectral characteristics are one of the important parameters for evaluating the performance of optical communication devices and systems. Amplitude and phase information are important parameters of fiber optic modulation format signals, and are crucial for analyzing modulation format quality and obtaining time-domain information such as time-domain chirp. Current spectrometers can acquire high-resolution amplitude spectrum information, but phase parameters require the optical signal to be converted into a radio frequency (RF) signal and measured in the RF domain. However, due to the bandwidth limitations of RF measurement instruments, typically below 50 GHz, there are problems such as small measurement range, low phase resolution, and measurement complexity, making it difficult to directly measure and obtain phase parameters related to wavelength resolution at the pm level in the optical domain. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a device and method for measuring phase parameters of fiber optic modulation format signals. It employs dual stimulated Brillouin frequency-selective amplification and beat frequency coherence phase parameter measurement techniques to achieve wavelength-related phase parameter measurement with wavelength resolution at the pm level.

[0006] In a first aspect, this disclosure provides a phase parameter measurement device for fiber optic modulation format signals, comprising: a pump module, a polarization depolarization module, a signal input module, a wavelength splitting module, a detection module, and a phase parameter extraction module;

[0007] The pump module is used to generate a wavelength-variable dual-pump signal. The dual-pump signal is depolarized by a depolarization module. After depolarization, part of the dual-pump signal enters the wavelength splitting module and part enters the detection module.

[0008] After the signal under test enters the wavelength splitting module, the signal under test and the dual pump signal are amplified by dual stimulated Brillouin frequency selection in the wavelength splitting module, and the spectral components of two adjacent wavelengths with wavelength resolution on the order of pm are output to the detection module.

[0009] The detection module is used to detect the dual-pump signal as a reference signal for phase parameter measurement, detect the beat frequency coherent signal generated by the spectral components of two adjacent wavelengths, and input the detected signal to the phase parameter extraction module. The phase parameter extraction module outputs the absolute phase parameter and relative phase parameter of the signal under test with wavelength resolution on the order of pm.

[0010] Further technical solutions also include a control and data processing module, used to regulate the pump module to generate dual pump signals of different wavelengths, and to perform data processing on the reference signal and the beat frequency coherent signal.

[0011] In a further technical solution, the pump module includes a tunable laser, a first optical isolator, and a Mach-Zehnder interferometer. The tunable laser is used to output signal light, and the optical signal passes through the first optical isolator and the Mach-Zehnder interferometer to output a dual-pump signal with a variable wavelength.

[0012] In a further technical solution, the depolarization module is used to output a polarization-independent power-tunable dual-pump signal that meets the measurement requirements, including a polarization scrambler, an optical attenuator, an optical amplifier, and an optical coupler.

[0013] The polarization scrambler is used to depolarize the dual-pump signal generated by the pump module. The optical attenuator and optical amplifier are used to adjust the power gain of the dual-pump signal. The optical coupler is used to separate a portion of the dual-pump signal and send it to the phase-sensitive detector of the detection module as a reference signal for phase measurement.

[0014] In a further technical solution, the signal input module includes a second optical isolator for receiving the signal to be tested.

[0015] A further technical solution is that the wavelength splitting module is used to output the spectral components of two adjacent wavelengths with a wavelength resolution of pm through dual stimulated Brillouin frequency selective amplification, including a first optical fiber link, a first optical circulator, a coupler, a second optical fiber link, and a second optical circulator.

[0016] After the signal under test passes through the first optical fiber link and the first optical circulator, it enters the second optical circulator through the second optical fiber link. At the same time, after passing through the first optical fiber link and the first optical circulator, the signal under test also enters the coupler and is coupled with part of the dual-pump signal output by the optical coupler in the depolarization module. The coupled signal then enters the second optical circulator and is sent together with the signal under test to the APD detector of the detection module.

[0017] In a further technical solution, the detection module includes a phase-sensitive detector and an APD detector. The phase-sensitive detector is used to detect a portion of the dual-pump signal, which serves as a reference signal for phase parameter measurement. The APD detector is used to detect the beat frequency coherent signal generated by the spectral components of two adjacent wavelengths output by the wavelength splitting module.

[0018] A further technical solution is that the principle of the fiber optic modulation format signal phase parameter measuring device for measuring phase parameters is as follows:

[0019] A double-sideband modulation of the tunable laser pump signal is performed using a Mach-Zend interferometer to generate a dual-pump signal. Based on the fiber stimulated Brillouin effect, the phase difference between two adjacent wavelengths of the signal under test is obtained by dual stimulated Brillouin frequency selective amplification and beat frequency coherence. By changing the wavelength of the dual-pump signal, the phase difference between two adjacent wavelengths at a series of different wavelength positions is obtained. The series of phase differences are accumulated, and the dual-pump signal is used as a phase reference signal to obtain the relative phase parameters and absolute phase parameters of the fiber modulation format signal.

[0020] Secondly, this disclosure provides a method for measuring the phase parameters of fiber optic modulation format signals, implemented based on the aforementioned fiber optic modulation format signal phase parameter measuring device, comprising:

[0021] Step 1: Input the modulation format signal of the fiber under test into the input channel of the optical fiber under test, and enter the wavelength splitting module;

[0022] Step 2: The output signal light of the tunable laser source is used to generate a dual-pump signal with tunable power through the pump module. The dual-pump signal is depolarized by the depolarization module. After depolarization, part of the dual-pump signal enters the wavelength splitting module and part enters the detection module.

[0023] Step 3: The fiber modulation format signal and the dual-pump signal are amplified by dual stimulated Brillouin frequency selection in the wavelength splitting module to output the spectral components of two adjacent wavelengths with wavelength resolution on the order of pm.

[0024] Step 4: The spectral components of two adjacent wavelengths generated undergo beat frequency coherence in the detection module and are converted into electrical signals, outputting a beat frequency coherent signal; the depolarized dual-pump signal is detected in the detection module and output as a reference signal for phase measurement.

[0025] Step 5: Output the absolute phase parameters and relative phase parameters of the signal under test with wavelength resolution in the order of pm through the phase parameter extraction module, and complete the wavelength-correlated phase parameter measurement of the fiber optic modulation format signal.

[0026] Further technical solutions also include:

[0027] The control and data processing module controls the pump module to continuously change the wavelength of the output pump signal, acquires a series of beat frequency coherent signals of two adjacent wavelengths at different wavelength positions and the corresponding reference signals, processes the reference signals and beat frequency coherent signals, and outputs the absolute phase parameters and relative phase parameters of the signal under test with wavelength resolution at the pm level through the phase parameter extraction module.

[0028] The above one or more technical solutions have the following beneficial effects:

[0029] 1. This invention provides a device and method for measuring phase parameters of fiber optic modulation format signals. It employs dual stimulated Brillouin frequency-selective amplification and beat frequency coherence phase parameter measurement technology to achieve accurate measurement of wavelength-related phase parameters with wavelength resolution on the order of pm in the C and L bands.

[0030] 2. The phase parameter measurement device and method proposed in this invention can easily measure the phase parameters of optical signals in different bands such as C-band, L-band, and O-band by replacing tunable lasers, detectors, etc.

[0031] 3. The phase parameter measurement device and method proposed in this invention can achieve wavelength-dependent phase parameter measurement with a minimum wavelength resolution of 0.1 pm, and the phase measurement accuracy is better than 0.5 pm. 0 It has superior measurement accuracy. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0033] Figure 1 This is a schematic diagram of the fiber optic modulation format signal phase parameter measurement device according to Embodiment 1 of the present invention.

[0034] The module consists of: 1. Pump module, 101. Tunable laser, 102. First optical isolator, 103. Mach-Zend interferometer; 2. Depolarization module, 201. Polarizer, 202. Optical attenuator, 203. Optical amplifier, 204. 1:99 optical coupler; 3. Input module for signal under test, 301. Signal under test, 302. Second optical isolator; 4. Wavelength splitting module, 401. First-stage fiber optic link, 402. First optical circulator, 403. 50:50 optical coupler; 404. Second-stage fiber optic link, 405. Second optical circulator; 5. Detection module, 501. Phase-sensitive detector, 502. APD detector; 6. Phase parameter extraction module; 7. Control and data processing module. Detailed Implementation

[0035] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Example 1

[0038] To address the problems existing in the background technology and enable the spectrometer to directly measure and acquire spectral phase parameters with wavelength resolution on the order of pm in the optical domain, this embodiment provides a fiber optic modulation format signal phase parameter measurement device, such as... Figure 1 As shown, it includes: a pump module 1, a depolarization module 2, a signal input module 3, a wavelength splitting module 4, a detection module 5, a phase parameter extraction module 6, and a control and data processing module 7. In this embodiment, a wavelength-tunable dual-pump signal is generated by pump module 1. The dual-pump signal is depolarized by depolarization module 2. After depolarization, part of the dual-pump signal enters wavelength splitting module 4, and part enters detection module 5. The signal under test enters wavelength splitting module 4 after passing through signal input module 3. In wavelength splitting module 4, the signal under test and the dual-pump signal are amplified by dual stimulated Brillouin frequency selection, and the spectral components of two adjacent wavelengths with a wavelength resolution of pm are output to detection module 5. Detection module 5 detects the dual-pump signal as a reference signal for phase parameter measurement, detects the beat frequency coherent signal generated by the spectral components of two adjacent wavelengths, and inputs the detected signal to phase parameter extraction module 6. Control and data processing module 7 regulates pump module 1 to generate dual-pump signals of different wavelengths, performs data processing on the reference signal and the beat frequency coherent signal, and outputs the absolute phase parameter and relative phase parameter of the signal under test with a wavelength resolution of pm through phase parameter extraction module 6.

[0039] The pump module 1 includes a tunable laser 101, a first optical isolator 102, and a Mach-Zehnder interferometer 103, configured to generate dual pump signals required for dual stimulated Brillouin frequency selective amplification of adjacent wavelengths with variable wavelengths. The tunable laser 101 is used to output signal light. This tunable laser 101 needs to have wavelength tuning resolution on the order of ppm or higher to meet the requirements of high-resolution wavelength-dependent phase parameter measurements. The optical signal passes through the first optical isolator 102 and the Mach-Zehnder interferometer 103 to output a dual pump signal with variable wavelengths. The Mach-Zehnder interferometer 103 has a side-mode suppression capability exceeding 40 dBm to generate adjacent dual pump signals with wavelength spacing that meet the phase measurement requirements, and has sufficiently low residual side modes to prevent side-mode interference with phase measurements and avoid generating false phase information.

[0040] The aforementioned depolarization module 2 is used to output a polarization-independent, power-tunable dual-pump signal that meets the measurement requirements. It includes a polarizer 201, an optical attenuator 202, an optical amplifier 203, and a 1:99 optical coupler 204. The polarizer 201 depolarizes the dual-pump signal generated by the pump module 1 to eliminate the influence of polarization effects during the dual stimulated Brillouin frequency-selective amplification process on phase parameter measurement. The optical attenuator 202 and optical amplifier 203 adjust the power gain of the dual-pump signal to generate a polarization-independent, power-tunable dual-pump signal that meets the measurement requirements. The 1:99 optical coupler 204 separates 1% of the dual-pump signal and sends it to the phase-sensitive detector of the detection module as a reference signal for phase measurement. In this embodiment, the optical attenuator 202 is a gain-tunable broadband optical attenuator with sufficient spectral attenuation ripple; the optical amplifier 203 is a gain-tunable broadband optical amplifier with a small-signal gain greater than 37 dB and amplification noise less than 3.5 dB.

[0041] The above-mentioned signal input module 3 includes a second optical isolator 302 for receiving the signal to be tested.

[0042] The aforementioned wavelength splitting module 4 is used to output the spectral components of two adjacent wavelengths with a wavelength resolution on the order of pm through dual stimulated Brillouin frequency selective amplification. It includes a first-stage fiber optic link 401, a first optical circulator 402, a 50:50 optical coupler 403, a second-stage fiber optic link 404, and a second optical circulator 405. The signal under test passes through the first fiber optic link 401 and the first optical circulator 402, and then enters the second optical circulator 405 through the second fiber optic link 404. At the same time, after passing through the first fiber optic link 401 and the first optical circulator 402, the signal under test also enters the 50:50 optical coupler 403, where it is coupled 1:1 with the 1% dual-pump signal output from the optical coupler in the depolarization module. The coupled signal then enters the second optical circulator 405 and is sent together with the signal under test to the APD detector 502 of the detection module 5.

[0043] In wavelength splitting module 4, the dual pump signal and the signal under test are amplified by the stimulated Brillouin effect through dual stimulated Brillouin frequency selection to obtain the spectral components of two adjacent wavelengths with wavelength resolution on the order of pm.

[0044] The aforementioned detection module 5 includes a phase-sensitive detector 501 and an APD detector 502. The phase-sensitive detector 501 is used to detect part of the dual-pump signal, which is used as a reference signal for phase parameter measurement. The APD detector 502 is used to detect the beat frequency coherent signal generated by the spectral components of two adjacent wavelengths output by the wavelength splitting module.

[0045] The phase parameter extraction module 6 is used to obtain wavelength-related absolute and relative phase parameters of the signal under test with wavelength resolution on the order of pm by using a series of beat frequency coherent signals of two adjacent wavelengths at different wavelength positions and a reference signal. The control and data processing module 7 is connected to and controls other modules and is configured to control the operation of the measuring device and process system parameters, as well as perform subsequent data processing on the obtained absolute and relative phase parameters.

[0046] The fiber optic modulation format signal phase parameter measurement device proposed in this embodiment has the following working process for measuring phase parameters:

[0047] The fiber optic modulation format signal to be measured enters the input module 3 and then enters the wavelength splitting module 4 from one end. The polarization-independent dual-pump signal generated by the pump module 1 and the depolarization module 2 enters the wavelength splitting module 4 from the other end. Then, the signal to be measured and the dual-pump signal are amplified by dual stimulated Brillouin frequency selection in the wavelength splitting module 4 to obtain the spectral components of two adjacent wavelengths with wavelength resolution at the pm level. The spectral components of the two wavelengths then beat coherently on the APD detector 502 of the detection module 5 and are converted into electrical signals. Combined with the 1% dual-pump signal used as a reference signal detected by the phase-sensitive detector 501 of the detection module 5, under the control of the control and data processing module 7, by continuously changing the wavelength of the output pump signal of the pump module 1, a series of beat coherent signals of two adjacent wavelengths at different wavelength positions and the corresponding reference signals are obtained. The phase parameter extraction module 6 obtains the wavelength-related absolute phase parameter and relative phase parameter of the signal to be measured at the pm level wavelength resolution, thus completing the phase parameter measurement of the fiber optic modulation format signal.

[0048] The principle of the aforementioned fiber optic modulation format signal phase parameter measurement device for measuring phase parameters is as follows:

[0049] A double-sideband modulation of the tunable laser pump signal is performed using a Mach-Zend interferometer to generate a dual-pump signal. Based on the fiber stimulated Brillouin effect, the phase difference between two adjacent wavelengths of the signal under test is obtained by dual stimulated Brillouin frequency selective amplification and beat frequency coherence. By changing the wavelength of the dual-pump signal, the phase difference between two adjacent wavelengths at a series of different wavelength positions is obtained. The series of phase differences are accumulated, and the dual-pump signal is used as a phase reference signal to obtain the relative phase parameters and absolute phase parameters of the fiber modulation format signal.

[0050] The fiber optic modulation format signal phase parameter measurement device proposed in this embodiment employs dual stimulated Brillouin frequency-selective amplification and beat-frequency coherence phase parameter measurement techniques. It achieves wavelength-related phase parameter measurement with a minimum wavelength resolution of 0.1 pm for optical signals in different bands (including C, L, and O bands), with a phase measurement accuracy better than 0.5 pm. 0 .

[0051] Example 2

[0052] Based on the above embodiments, this embodiment provides a method for measuring the phase parameters of fiber optic modulation format signals, including the following steps:

[0053] Step 1: Input the signal of the fiber under test modulation format into the input channel of the optical input module 3, and enter the wavelength splitting module 4 from one end.

[0054] Step 2: The output signal light of the tunable laser source is used to generate a dual-pump signal with tunable power through the pump module 1. The dual-pump signal is depolarized through the depolarization module 2. After depolarization, part of the dual-pump signal enters the wavelength splitting module 4 and part enters the detection module 5.

[0055] Specifically, the output signal light from the tunable laser source passes through a first optical isolator 102, a Mach-Zehnder interferometer 103, a polarizer 201, an optical attenuator 202, and an optical amplifier 203 to generate a polarization-independent, power-tunable dual-pump signal that meets measurement requirements. This signal is then injected into the other end of the wavelength splitter module as a pump signal. The power level of the dual-pump signal can be dynamically adjusted based on parameters such as the wavelength range, wavelength resolution, and dynamic range measured by the phase parameters.

[0056] Step 3: The fiber modulation format signal and the dual-pump signal are amplified by dual stimulated Brillouin frequency selection in the wavelength splitting module 4, and the spectral components of two adjacent wavelengths with wavelength resolution on the order of pm are output.

[0057] Step 4: The spectral components of two adjacent wavelengths generated undergo beat frequency coherence on the APD detector 502 of the detection module and are converted into electrical signals, outputting a beat frequency coherent signal; the 1% dual-pump signal, which is depolarized by the depolarization module 2 and output by the 1:99 optical coupler, is detected on the phase-sensitive detector 501 of the detection module and output as a reference signal for phase measurement.

[0058] Step 5: Through the control and data processing module 7, the pump module is controlled to continuously change the wavelength of the output pump signal to obtain a series of beat frequency coherent signals of two adjacent wavelengths at different wavelength positions and the corresponding reference signals. Through the phase parameter extraction module 6, the absolute phase parameter and relative phase parameter of the signal under test with wavelength resolution at the pm level are output to complete the wavelength-correlated phase parameter measurement of the fiber modulation format signal.

[0059] This embodiment, through the above-described scheme, employs dual stimulated Brillouin frequency-selective amplification and beat-frequency coherent phase parameter measurement techniques to achieve accurate measurement of wavelength-related phase parameters with a wavelength resolution on the order of pm in the C and L bands.

[0060] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0062] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A device for measuring phase parameters of fiber optic modulated signal, characterized in that, include: Pump module, depolarization removal module, signal input module, wavelength splitting module, detection module, phase parameter extraction module; The pump module is used to generate a wavelength-variable dual-pump signal. The dual-pump signal is depolarized by a depolarization module. After depolarization, part of the dual-pump signal enters the wavelength splitting module and part enters the detection module. After the signal under test enters the wavelength splitting module, the signal under test and the dual pump signal are amplified by dual stimulated Brillouin frequency selection in the wavelength splitting module, and the spectral components of two adjacent wavelengths with wavelength resolution on the order of pm are output to the detection module. The detection module is used to detect the dual-pump signal as a reference signal for phase parameter measurement, detect the beat frequency coherent signal generated by the spectral components of two adjacent wavelengths, and input the detected signal to the phase parameter extraction module. The phase parameter extraction module outputs the absolute phase parameter and relative phase parameter of the signal under test with wavelength resolution on the order of pm.

2. The fiber optic modulation format signal phase parameter measurement device as described in claim 1, characterized in that, It also includes a control and data processing module for regulating the pump module to generate dual pump signals of different wavelengths, and for performing data processing on the reference signal and the beat frequency coherent signal.

3. The fiber optic modulation format signal phase parameter measurement device as described in claim 1, characterized in that, The pump module includes a tunable laser, a first optical isolator, and a Mach-Zehnder interferometer. The tunable laser is used to output signal light, and the optical signal passes through the optical isolator and the Mach-Zehnder interferometer to output a dual-pump signal with a variable wavelength.

4. The fiber optic modulation format signal phase parameter measurement device as described in claim 1, characterized in that, The polarization depolarization module is used to output a polarization-independent, power-tunable dual-pump signal that meets the measurement requirements, and includes a polarization scrambler, an optical attenuator, an optical amplifier, and an optical coupler. The polarization scrambler is used to depolarize the dual-pump signal generated by the pump module. The optical attenuator and optical amplifier are used to adjust the power gain of the dual-pump signal. The optical coupler is used to separate a portion of the dual-pump signal and send it to the phase-sensitive detector of the detection module as a reference signal for phase measurement.

5. The fiber optic modulation format signal phase parameter measurement device as described in claim 1, characterized in that, The signal input module includes a second optical isolator for receiving the signal to be tested.

6. The fiber optic modulation format signal phase parameter measurement device as described in claim 1, characterized in that, The wavelength splitting module is used to output the spectral components of two adjacent wavelengths with a wavelength resolution on the order of pm through dual stimulated Brillouin frequency selective amplification, including a first optical fiber link, a first optical circulator, a coupler, a second optical fiber link, and a second optical circulator. After the signal under test passes through the first optical fiber link and the first optical circulator, it enters the second optical circulator through the second optical fiber link. At the same time, after passing through the first optical fiber link and the first optical circulator, the signal under test also enters the coupler and is coupled with part of the dual-pump signal output by the optical coupler in the depolarization module. The coupled signal then enters the second optical circulator and is sent together with the signal under test to the APD detector of the detection module.

7. The fiber optic modulation format signal phase parameter measurement device as described in claim 1, characterized in that, The detection module includes a phase-sensitive detector and an APD detector. The phase-sensitive detector is used to detect part of the dual-pump signal, which is used as a reference signal for phase parameter measurement. The APD detector is used to detect the beat frequency coherent signal generated by the spectral components of two adjacent wavelengths output by the wavelength splitting module.

8. The fiber optic modulation format signal phase parameter measurement device as described in claim 1, characterized in that, The principle of the fiber optic modulation format signal phase parameter measuring device for measuring phase parameters is as follows: A double-sideband modulation of the tunable laser pump signal is performed using a Mach-Zend interferometer to generate a dual-pump signal. Based on the fiber stimulated Brillouin effect, the phase difference between two adjacent wavelengths of the signal under test is obtained by dual stimulated Brillouin frequency selective amplification and beat frequency coherence. By changing the wavelength of the dual-pump signal, the phase difference between two adjacent wavelengths at a series of different wavelength positions is obtained. The series of phase differences are accumulated, and the dual-pump signal is used as a phase reference signal to obtain the relative phase parameters and absolute phase parameters of the fiber modulation format signal.

9. A method for measuring phase parameters of fiber optic modulation format signals, implemented based on the fiber optic modulation format signal phase parameter measuring device as described in any one of claims 1-8, characterized in that, include: The modulation format signal of the optical fiber under test is input into the input channel of the optical fiber under test and then enters the wavelength splitting module. The tunable laser source outputs signal light, which generates a dual-pump signal with tunable power through a pump module. The dual-pump signal is depolarized by a depolarization module. After depolarization, part of the dual-pump signal enters the wavelength splitting module and part enters the detection module. The fiber modulation format signal under test and the dual-pump signal are amplified by dual stimulated Brillouin frequency selection in the beam splitter module, and the spectral components of two adjacent wavelengths with wavelength resolution on the order of pm are output. The spectral components of two adjacent wavelengths generated undergo beat frequency coherence in the detection module and are converted into electrical signals, outputting a beat frequency coherent signal; the depolarized dual-pump signal is detected in the detection module and output as a reference signal for phase measurement. The phase parameter extraction module outputs the absolute and relative phase parameters of the signal under test with wavelength resolution on the order of pm, thus completing the wavelength-correlated phase parameter measurement of the fiber optic modulation format signal.

10. The method for measuring phase parameters of fiber optic modulation format signals as described in claim 9, characterized in that it further includes... include: The control and data processing module controls the pump module to continuously change the wavelength of the output pump signal, acquires a series of beat frequency coherent signals of two adjacent wavelengths at different wavelength positions and the corresponding reference signals, processes the reference signals and beat frequency coherent signals, and outputs the absolute phase parameters and relative phase parameters of the signal under test with wavelength resolution at the pm level through the phase parameter extraction module.

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