An optical amplification and evaluation system based on optical injection locking

Abstract

The present invention provides an optical amplification and evaluation system based on optical injection locking, which uses an optical injection path to perform intensity modulation of input laser and first and second modulations of output light; uses a first feedback loop to couple intensity modulated light and first modulated light to obtain first coupled light, and feeds back a first error signal between the first coupled light and a first radio frequency reference signal to the optical injection path, thereby adjusting the phase of the first modulation; uses a second feedback loop to couple second modulated light and input laser to obtain second coupled light, and feeds back a second error signal between the second coupled light and a second radio frequency reference signal to the optical injection path, thereby adjusting the phase of the second modulation, so that the phase and frequency of the input laser are consistent with the output laser, thereby achieving phase and frequency locking of optical injection. The present invention can not only realize long-distance optical amplification, but also ensure the stability of the transmitted signal and the effective suppression of phase noise, thereby ensuring optical frequency transmission of coherent light.

Description

Technical Field

[0001] The invention belongs to the technical field of optical frequency transfer, and in particular relates to an optical amplification and evaluation system based on light injection locking. Background Art

[0002] Optical amplification is necessary to extend the distance of optical frequency transmission and has a significant impact on transmission performance. Optical frequency transmission faces two challenges when the transmission distance becomes longer. One challenge of long-distance optical frequency transmission is the phase noise added to the light by acoustic, mechanical and thermal disturbances in the optical fiber. The other is the loss of the signal when it is transmitted through the optical fiber. For light with a wavelength of around 1550 nanometers, the attenuation of standard silica optical fiber is about 0.2 dB / km. In addition, if the loss of joints and connectors is taken into account, the effective attenuation can be greater than 0.25 dB / km.

[0003] The traditional EDFA (Erbium-doped Optical Fiber Amplifier) ​​is the most commonly used fiber amplifier in optical frequency transmission. Although EDFA can achieve optical amplification, its maximum gain is limited due to its bidirectional amplification characteristics. In addition, when using EDFA for amplification, unnecessary optical loss is generated due to end face reflection and Rayleigh scattering. EDFA is a bidirectional amplification and cannot use an isolator. In addition, the influence of ASE (Amplifier Spontaneous Emission) noise makes it easy to trigger the laser effect. When the optical fiber link is too long, the EDFA gain is small and cannot compensate for the optical power loss. Generally, the optimal gain is limited to about 20 dB, and the distance between adjacent EDFAs does not exceed 100km, otherwise the excess loss will accumulate over long distances. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides an optical amplification and evaluation system based on optical injection locking. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0005] The present invention provides an optical amplification and evaluation system based on optical injection locking, comprising:

[0006] An optical injection path is used to split a first main laser beam input to an optical amplification and evaluation system based on optical injection locking, and use one of the laser beams as an input laser beam; inject the input laser beam from the optical injection port, and output a first output light consistent with the output power of the slave laser; modulate the intensity of the first main laser beam to obtain intensity modulated light; phase modulate the first output light according to a first error signal to obtain a first modulated light; phase modulate the first modulated light according to a second error signal to obtain a second modulated light;

[0007] A first feedback loop is used to couple the first modulated light and the intensity modulated light to obtain a first coupled light; and according to a first error signal between the first coupled light and the first radio frequency reference signal, feedback is used to adjust the frequency of the injected slave laser and the phase of the first modulated light so that the frequency and phase of the first modulated light are consistent with those of the input laser;

[0008] A second feedback loop is used to couple the input laser and the second modulated light to obtain a second coupled light; and according to a second error signal between the second coupled light and the second radio frequency reference signal, the phase of the second modulated light is adjusted by feedback so that the second modulated light is consistent with the phase of the input laser;

[0009] A feedback evaluation loop is used to determine the phase difference between the electrical signals of the forward and reverse optical paths.

[0010] Beneficial effects:

[0011] The present invention provides an optical amplification and evaluation system based on optical injection locking, which uses an optical injection path to modulate the intensity of an input laser and to modulate the output light for the first time and the second time; uses a first feedback loop to couple the intensity modulated light and the first modulated light to obtain a first coupled light, and feeds back a first error signal between the first coupled light and a first radio frequency reference signal to the optical injection path, thereby adjusting the phase of the first modulation; uses a second feedback loop to couple the second modulated light and the input laser to obtain a second coupled light, and feeds back a second error signal between the second coupled light and a second radio frequency reference signal to the optical injection path, thereby adjusting the phase of the second modulation, so that the phase and frequency of the input laser are consistent with the output laser, and the phase and frequency locking of the optical injection is achieved. The present invention can not only realize long-distance optical amplification, but also ensure the stability of the transmitted signal and the effective suppression of phase noise, thereby ensuring that the coherent light performs optical frequency transmission.

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of an optical amplification and evaluation system based on optical injection locking provided by the present invention. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0015] Optical injection locking refers to the light emitted by the master laser entering the slave laser. The slave laser is a semiconductor laser. The injected light forces the slave laser to overcome the spontaneous radiation in the cavity, and the final output follows the frequency of the master laser with a fixed phase offset, where the phase offset depends on the frequency detuning amount between the master and slave lasers. In optical injection locking, as long as the frequency detuning amount between the free-running injected light and the free-running slave laser is guaranteed ( ) is less than the bandwidth of the input optical signal, the slave laser can be successfully injected by the master laser. Then the power of the injected signal light is equal to that of the slave laser, and the frequency is the same as that of the master laser, thus achieving amplification. Therefore, the greater the output power of the slave laser, the greater the gain of the optical amplification.

[0016] The conditions for optical injection locking are determined by two parameters: first, the injection ratio, defined as the power ratio between the input field intensity of the slave laser and the internal field intensity, and second, the frequency detuning between the injected master laser and the undisturbed slave laser field. Decide.

[0017] Optical injection locking has many advantages and applications: 1. It can force a noisy slave laser to act as a high-quality frequency replica of a low-noise master laser; 2. It can reduce chirp in intensity modulation schemes; 3. It can increase the modulation bandwidth of the slave laser; 4. It can amplify and filter light at the same time; it can also be used for pump recovery and narrowband optical amplification. Therefore, designing an optical amplification scheme based on optical injection locking has important practical significance.

[0018] like Figure 1 As shown, the present invention provides an optical amplification and evaluation system based on optical injection locking, comprising:

[0019] An optical injection path is used to split a first main laser beam input to an optical amplification and evaluation system based on optical injection locking, and use one of the laser beams as an input laser beam; inject the input laser beam from the optical injection port, and output a first output light consistent with the output power of the slave laser; modulate the intensity of the first main laser beam to obtain intensity modulated light; phase modulate the first output light according to a first error signal to obtain a first modulated light; phase modulate the first modulated light according to a second error signal to obtain a second modulated light;

[0020] In a specific embodiment of the present invention, the light injection path of the present invention comprises:

[0021] A first beam splitter is used to split the first main laser into two beams, and send one of the beams to the second beam splitter as the second main laser, and the other beam is used as the third main laser;

[0022] a second beam splitter, used for splitting the second main laser into two beams, sending one of the beams as the fourth main laser to the third beam splitter, and sending the other beam as the fifth main laser to the second feedback loop;

[0023] a third beam splitter, splitting the fourth main laser into two beams, and sending one of the beams to the fourth beam splitter as the sixth main laser, and sending the other beam as the seventh main laser;

[0024] a fourth beam splitter, which splits the sixth main laser into two beams, and sends one of the beams as the eighth main laser to the circulator, and sends the other beam as the ninth main laser to the intensity modulator;

[0025] a circulator, used for inputting the eighth master laser from the corresponding light injection port and outputting output light consistent with the output power of the slave laser;

[0026] The injected light enters through port 1 of the circulator and is injected into the slave laser through port 2. The injected light forces the slave laser to overcome the spontaneous radiation in the cavity and eventually follow the frequency of the master laser. Port 3 of the slave circulator outputs light with the same power as the slave laser, thus achieving amplification.

[0027] an intensity modulator, used for performing intensity modulation on the ninth main laser to obtain intensity modulated light;

[0028] It is worth noting that the present invention realizes phase noise suppression of the output light through the first acousto-optic modulator and the second acousto-optic modulator, and calculates and evaluates the phase noise suppression degree of the system through the third acousto-optic modulator, the first photodetector and the fourth photodetector, so that the system can not only realize optical amplification, but also ensure that the phase noise is effectively suppressed.

[0029] A first acousto-optic modulator, configured to phase-modulate the first output light according to the first error signal to obtain a first modulated light;

[0030] a fifth beam splitter, used for splitting the first modulated light into two beams, and sending one of the beams as the first modulated sub-light to the second acousto-optic modulator, and sending the other beam as the first light to be coupled to the first feedback loop;

[0031] A second acousto-optic modulator, configured to phase-modulate the first modulated light according to a second error signal to obtain a second modulated light;

[0032] The sixth beam splitter is used to split the second modulated light into two beams, one of which is sent to the feedback evaluation loop, and the other is sent to the second feedback loop as the second light to be coupled.

[0033] A monitoring port is provided between the circulator and the first acousto-optic modulator, through which it is monitored whether the frequency of the first output light is consistent with that of the second main laser. If they are consistent, it indicates that the injection of the second main laser is successful; if they are inconsistent, it indicates that the injection of the second main laser fails. When the injection of the second main laser fails, the frequency of the first output light is consistent with the frequency of the slave laser.

[0034] It is worth noting that the intensity modulator is used to generate modulation on the intensity of the second master laser so as to increase the dynamic tracking range of the slave laser; the function of the first acousto-optic modulator is to lock the phase noise of the slave laser.

[0035] exist Figure 1 In the figure, the master laser emits the master laser, that is, the master laser at point A. The first beam splitter divides the master laser into two beams, one of which is sent to the second beam splitter as the second master laser, that is, point B, and the other is sent to the third acousto-optic modulator as the third master laser. The second beam splitter divides the second master laser into two beams, one of which is sent to the third beam splitter as the fourth master laser, and the other is sent to the second coupler as the fifth master laser. The third beam splitter divides the fourth laser into two beams, one of which is sent to the fourth beam splitter as the sixth master laser, and the other is sent to the first Faraday rotator as the seventh master laser. The fourth beam splitter divides the sixth master laser into two beams, one of which is sent to the circulator as the eighth master laser, and the other is sent to the intensity modulator as the ninth master laser. The eighth master laser is injected through port 2 of the circulator. Port 2 of the circulator is bidirectional. After injection, the eighth master laser comes out from port 2 and then outputs from port 3. The size of the first output light after successful injection is the power size of the slave laser, and the frequency is consistent with the frequency of the eighth master laser. Therefore, the effect of optical amplification is achieved.

[0036] A first feedback loop is used to couple the first modulated light and the intensity modulated light to obtain a first coupled light; and according to a first error signal between the first coupled light and the first radio frequency reference signal, feedback is used to adjust the frequency of the injected slave laser and the phase of the first modulated light so that the frequency and phase of the first modulated light are consistent with those of the input laser;

[0037] It is worth noting that, in the present invention, the frequency of the output light of the circulator is consistent with that of the second main laser through the feedback of the first feedback loop, that is, successful locking is achieved.

[0038] In a specific embodiment of the present invention, the first feedback loop includes:

[0039] A first coupler, used for coupling the first light to be coupled and the intensity modulated light to obtain the first coupled light;

[0040] A second photodetector, used for converting the first coupled light into a first electrical signal;

[0041] A first mixer, configured to mix the first electrical signal and the first radio frequency reference signal to obtain a first error signal;

[0042] The first proportional-integral-differential controller is used to process the first error signal to obtain a processed signal, feed it back to the slave laser to change the frequency of the slave laser, and synchronously feed it back to the first acousto-optic modulator to enable the first acousto-optic modulator to adjust the phase of the first modulated light.

[0043] It is worth noting that after the injection is successful, the first electrical signal detected by the second photodetector is input into the first mixer, and the mixer mixes the first electrical signal and the first RF reference signal to obtain a first error signal, and sends the first error signal to the first proportional integral differential controller. The first proportional integral differential controller processes it and then divides it into two paths, one path is sent to the first acousto-optic modulator for locking the phase of the slave laser, and the other path controls the slave laser current through feedback to change the phase of the first modulated light, so that the phases of point B and the first modulated light are consistent.

[0044] The second feedback loop is used to couple the input laser and the second modulated light to obtain a second coupled light; according to a second error signal between the second coupled light and a second radio frequency reference signal, the phase of the second modulated light is adjusted by feedback so that the second modulated light is consistent with the phase of the input laser.

[0045] A feedback evaluation loop is used to determine the phase difference between the electrical signals of the forward and reverse optical paths.

[0046] It is worth noting that there are two forward optical paths, one is from the first beam splitter through the third acousto-optic modulator to the sixth beam splitter, and the other is from the first beam splitter, the circulator, the first acousto-optic modulator, the second acousto-optic modulator to the sixth beam splitter. These two paths of light beat in the sixth beam splitter to form the first beat frequency light, which arrives at the third photodetector, that is, the third photodetector detects the electrical signal of the light in the forward optical path. There are two reverse optical paths, one is the light reflected by the first Faraday rotator to the third beam splitter, and then passes through the second beam splitter to the first beam splitter; the other is the light reflected by the second Faraday rotator to the seventh beam splitter, which is fed back to the third acousto-optic modulator through the sixth beam splitter, and then to the first beam splitter. These two paths of light beat in the first beam splitter to form the second beat frequency light, which arrives at the first photodetector, that is, the first photodetector detects the electrical signal of the light in the reverse optical path.

[0047] If the electrical signals of the forward optical path and the reverse optical path are known, the required phase information can be obtained from the electrical signals of the two. The smaller the phase difference between the two, the better the system suppresses phase noise, thus eliminating the influence of the asymmetric part of the system.

[0048] The present invention provides an optical amplification and evaluation system based on optical injection locking, which uses an optical injection path to modulate the intensity of an input laser and to modulate the output light for the first time and the second time; uses a first feedback loop to couple the intensity modulated light and the first modulated light to obtain a first coupled light, and feeds back a first error signal between the first coupled light and a first radio frequency reference signal to the optical injection path, thereby adjusting the frequency and phase of the first modulation; uses a second feedback loop to couple the first modulated light and the input laser to obtain a second coupled light, and feeds back a second error signal between the second coupled light and a second radio frequency reference signal to the optical injection path, thereby adjusting the phase of the second modulation, so that the phase and frequency of the input laser are consistent with the output laser, and the phase and frequency locking of the optical injection is achieved. The present invention can not only achieve long-distance optical amplification, but also ensure the stability of the transmitted signal and the effective suppression of phase noise, thereby ensuring that the coherent light performs optical frequency transmission.

[0049] In a specific embodiment of the present invention, the second feedback loop includes:

[0050] A second coupler, used for coupling the fifth main laser and the second light to be coupled to obtain a second coupled light;

[0051] a fourth photodetector, configured to convert the second coupled light into a second electrical signal;

[0052] A second mixer, used for mixing the second electrical signal and the second radio frequency reference signal to obtain a second error signal;

[0053] The second PI / D controller is used to process the second error signal to obtain a second processed signal, and feed the second processed signal back to the second AOM so that the second AOM adjusts the phase of the second modulated light.

[0054] refer to Figure 1 , the second acousto-optic modulator outputs the second modulated light, i.e., point C. The second modulated light is then sent to the second coupler, and the second coupler couples the fifth main laser split by the second beam splitter with the second modulated light, and sends it to the fourth photodetector, which converts it into a second electrical signal and sends it to the second proportional integral differential controller to feedback control the modulation phase of the second acousto-optic modulator, and finally makes the second modulated light consistent with the phase of the fifth laser, so as to suppress the phase noise of points B and C, thereby achieving phase locking of the input laser and the output laser.

[0055] In a specific embodiment of the present invention, the feedback evaluation loop includes:

[0056] A third acousto-optic modulator, used for phase-modulating the third main laser to obtain a third modulated light, and sending the third modulated light to a sixth beam splitter;

[0057] The sixth beam splitter is further used to beat the third modulated light and the second modulated light to obtain the first beat frequency light, and send the third modulated light and the first beat frequency light to the seventh beam splitter;

[0058] a seventh beam splitter, configured to send the first beat frequency light to a third photodetector and send the third modulated light to a second Faraday rotator mirror;

[0059] Among them, the first beam splitter and the sixth beam splitter are X-type beam splitters, and the second to fifth beam splitters and the seventh beam splitter are all Y-type beam splitters.

[0060] a third photodetector, configured to convert the first beat frequency light into an electrical signal;

[0061] a first Faraday rotator mirror, for injecting the seventh main laser light and reflecting the seventh main laser light back to the third beam splitter, so as to be reflected back to the first beam splitter through the third beam splitter and the second beam splitter;

[0062] It is worth noting that in Figure 1 In the embodiment, the light reflected by the first Faraday rotation mirror back to the third beam splitter does not enter the second coupler, but is reflected along point B to point A until it reaches the first beam splitter.

[0063] a second Faraday rotator mirror, used for reflecting the third modulated light to the seventh beam splitter;

[0064] The seventh beam splitter is further used to send the light reflected by the second Faraday rotation mirror to the sixth beam splitter;

[0065] a sixth beam splitter, further used to feed back the light transmitted by the seventh beam splitter to the third acousto-optic modulator;

[0066] The third acousto-optic modulator is further used to modulate the light fed back by the sixth beam splitter and return the light to the first beam splitter;

[0067] The first beam splitter is further used to beat the light returned by the third acousto-optic modulator with the light returned by the second beam splitter to obtain a second beat frequency light;

[0068] The first photodetector is used to convert the second beat frequency light into an electrical signal.

[0069] The feedback evaluation loop further includes an evaluation electronic device for calculating the phase difference carried by the electrical signals converted from the first beat frequency light and the second beat frequency light.

[0070] The present invention can perform calculation and comparison through the electrical signals detected by the first photodetector and the third photodetector to confirm whether the system effectively suppresses the phase noise and eliminates the influence of the asymmetric optical path.

[0071] For example, assuming that the phase of the input light at point A is , the phase after the third AOM is , the phase information carried by the light after it goes back and forth through the third AOM and then returns to point A is , at this time the phase information of the electrical signal detected by the first photodetector is , the phase of point C is , then the phase of the signal detected by the third photodetector is The frequency of the electrical signal detected by the first photodetector is divided by two, and then the frequency of the electrical signal detected by the third photodetector is subtracted. The phase information carried by the calculated frequency is , the required phase information can be obtained to confirm whether the system has eliminated the influence of the asymmetric part.

[0072] The phase difference calculation part of the present invention can be performed on an evaluation electronic device, which has a calculation function. The calculation process can be implemented using existing electronic devices, and the specific calculation process of the electronic device will not be described here.

[0073] In a specific embodiment of the present invention, continue to refer to Figure 1 A monitoring port is provided between the circulator and the first acousto-optic modulator, and whether the frequency of the first output light is consistent with the second main laser is monitored through the monitoring port. If consistent, it indicates that the second main laser injection is successful; if inconsistent, it indicates that the second main laser injection fails;

[0074] When the second main laser injection fails, the frequency of the first output light is consistent with the frequency of the slave laser.

[0075] In a specific embodiment of the present invention, continue to refer to Figure 1 An output port is also provided between the sixth beam splitter and the second acousto-optic modulator, and the output port outputs the light amplified by the optical amplification and evaluation system based on optical injection locking.

[0076] It is worth noting that the light amplified by the optical amplification and evaluation system based on optical injection locking is the second modulated light.

[0077] It is worth noting that the terms "first" and "second" in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0078] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality of components or steps.

[0079] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. An optical amplification and evaluation system based on optical injection locking, characterized in that: include: An optical injection path is used to split a first main laser beam input to the optical amplification and evaluation system based on optical injection locking, and use one of the laser beams as an input laser beam; inject the input laser beam from the optical injection port, and output a first output light consistent with the output power of the slave laser; modulate the intensity of the first main laser beam to obtain intensity modulated light; phase modulate the first output light according to a first error signal to obtain a first modulated light; and phase modulate the first modulated light according to a second error signal to obtain a second modulated light; A first feedback loop is used to couple the first modulated light and the intensity modulated light to obtain a first coupled light; and according to a first error signal between the first coupled light and a first radio frequency reference signal, feedback is used to adjust the frequency of the injected slave laser and the phase of the first modulated light so that the frequency and phase of the first modulated light are consistent with those of the input laser; a second feedback loop, for coupling the input laser and the second modulated light to obtain a second coupled light; and feedback-adjusting the phase of the second modulated light according to a second error signal between the second coupled light and a second radio frequency reference signal, so that the second modulated light is consistent in phase with the input laser; A feedback evaluation loop for determining a phase difference between the electrical signals of the forward optical path and the reverse optical path; The light injection path comprises: A first beam splitter is used to split the first main laser into two beams, and send one of the beams as the second main laser to the second beam splitter, and the other beam as the third main laser; The second beam splitter is used to split the second main laser into two beams, and send one of the beams as the fourth main laser to the third beam splitter, and send the other beam as the fifth main laser to the second feedback loop; The third beam splitter splits the fourth main laser into two beams, and sends one of the beams to the fourth beam splitter as the sixth main laser, and the other beam is used as the seventh main laser; The fourth beam splitter splits the sixth main laser into two beams, and sends one beam as the eighth main laser to the circulator, and sends the other beam as the ninth main laser to the intensity modulator; The circulator is used to input the eighth master laser from the corresponding light injection port and output an output light consistent with the output power of the slave laser; The intensity modulator is used to modulate the intensity of the ninth main laser to obtain intensity modulated light; A first acousto-optic modulator, configured to phase-modulate the first output light according to a first error signal to obtain a first modulated light; a fifth beam splitter, used for splitting the first modulated light into two beams, and sending one beam as the first modulated sub-light to the second acousto-optic modulator, and sending the other beam as the first light to be coupled to the first feedback loop; The second acousto-optic modulator is used to phase-modulate the first modulated sub-light according to a second error signal to obtain a second modulated light; a sixth beam splitter, used for splitting the second modulated light into two beams, wherein one beam is sent to the feedback evaluation loop, and the other beam is sent to the second feedback loop as the second light to be coupled; The first feedback loop comprises: A first coupler, used for coupling the first light to be coupled and the intensity modulated light to obtain a first coupled light; a second photodetector, configured to convert the first coupled light into a first electrical signal; A first mixer, configured to mix the first electrical signal and a first radio frequency reference signal to obtain a first error signal; a first proportional-integral-differential controller, configured to process the first error signal to obtain a processed signal, feed the processed signal back to the slave laser to change the frequency of the slave laser, and synchronously feed the processed signal back to the first acousto-optic modulator to enable the first acousto-optic modulator to adjust the phase of the first modulated light; The second feedback loop comprises: A second coupler, used for coupling the fifth main laser and the second light to be coupled to obtain a second coupled light; a fourth photodetector, configured to convert the second coupled light into a second electrical signal; A second mixer, configured to mix the second electrical signal with a second radio frequency reference signal to obtain a second error signal; a second PI / D controller, configured to process the second error signal to obtain a second processed signal, and feed the second processed signal back to the second AOM so that the second AOM adjusts the phase of the second modulated light; The feedback evaluation loop includes: a third acousto-optic modulator, used for performing phase modulation on the third main laser to obtain a third modulated light, and sending the third modulated light to the sixth beam splitter; The sixth beam splitter is further used to beat the third modulated light and the second modulated light to obtain a first beat frequency light, and send the third modulated light and the first beat frequency light to the seventh beam splitter; a seventh beam splitter, configured to send the first beat frequency light to a third photodetector and send the third modulated light to a second Faraday rotator mirror; The third photodetector is used to convert the first beat frequency light into an electrical signal; a first Faraday rotator mirror, for injecting the seventh main laser light and reflecting the seventh main laser light back to the third beam splitter, so as to be reflected back to the first beam splitter through the third beam splitter and the second beam splitter; The second Faraday rotator mirror is used to reflect the third modulated light to the seventh beam splitter; The seventh beam splitter is further used to send the light reflected by the second Faraday rotator mirror to the sixth beam splitter; The sixth beam splitter is further used to feed back the light transmitted by the seventh beam splitter to the third acousto-optic modulator; The third acousto-optic modulator is further used to modulate the light fed back by the sixth beam splitter and return the light to the first beam splitter; The first beam splitter is further used to beat the light returned by the third acousto-optic modulator with the light returned by the second beam splitter to obtain second beat frequency light; The first photodetector is used to convert the second beat frequency light into an electrical signal.

2. The optical amplification and evaluation system based on optical injection locking according to claim 1, characterized in that: The feedback evaluation loop further includes an evaluation electronic device for calculating the phase difference carried by the electrical signals converted from the first beat frequency light and the second beat frequency light.

3. The optical amplification and evaluation system based on optical injection locking according to claim 1, characterized in that: A monitoring port is provided between the circulator and the first acousto-optic modulator, and whether the frequency of the first output light is consistent with the second main laser is monitored through the monitoring port, if consistent, it indicates that the second main laser injection is successful, if inconsistent, it indicates that the second main laser injection fails; Wherein, when the injection of the second main laser fails, the frequency of the first output light is consistent with the frequency of the slave laser.

4. The optical amplification and evaluation system based on optical injection locking according to claim 1, characterized in that: The first beam splitter and the sixth beam splitter are X-type beam splitters, and the second to fifth and seventh beam splitters are Y-type beam splitters.

5. The optical amplification and evaluation system based on optical injection locking according to claim 1, characterized in that: An output port is also provided between the sixth beam splitter and the second acousto-optic modulator, and the output port outputs the light amplified by the optical amplification and evaluation system based on optical injection locking.

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