Apparatus and method for improving stability of a vacuum squeezed light field generator

Abstract

The application discloses a device and method for improving the stability of a vacuum squeezed light field generator, and relates to the technical field of quantum optics. First, the cavity length of the vacuum squeezed light field generator is closed-loop locked by reflecting pump light. Then, seed light is resonated with the vacuum squeezed light field generator, and the power and spot mode of the seed light and local light are coupled and interfered after matching. The phase is adjusted to constructive interference, and an interference signal and its frequency spectrum are collected by using a Fourier real-time analysis oscilloscope to identify additional noise. Finally, noise is suppressed by combining air floating platform pressure optimization and negative feedback servo control system parameter adjustment, so that the stability of the vacuum squeezed light field generator is improved. The application can effectively improve the stability of the vacuum squeezed light field generator, and is widely applied to experimental systems for vacuum squeezed light field preparation.

Description

[0001] Method Domain This invention relates to the field of quantum optics, and in particular to an apparatus and method for improving the stability of a vacuum compressed state light field generator.

[0002] Background Method Vacuum-compressed light fields are an important non-classical light field resource, playing a central role in fields such as quantum key distribution, gravitational wave detection, and quantum precision measurement. As the core device for preparing compressed light fields, the operational stability of the vacuum-compressed light field generator directly determines key performance parameters such as the compressibility and noise level of the output light field.

[0003] However, in actual operation, vacuum compressed optical field generators are susceptible to external environmental disturbances, such as temperature fluctuations, mechanical vibrations, and internal component drift, including thermal deformation of the cavity mirror and crystal, and aging of piezoelectric ceramics. These disturbances cause minute changes in the cavity length of the optical resonator. Instability in the cavity length can disrupt the resonance condition, leading to problems such as attenuation of the compressibility of the output optical field and the introduction of additional noise.

[0004] Existing technologies mostly employ a single cavity length locking scheme, such as adjusting the cavity length using a negative feedback servo control system by detecting the reflected signal of the pump light. However, this type of scheme has drawbacks. Existing schemes lack real-time monitoring and feedback on the stability of the vacuum compressed light field generator, making it difficult to accurately locate the root cause of stability problems. This results in low parameter adjustment efficiency and limited stability improvement during the locking process.

[0005] Therefore, an apparatus and method for improving the stability of a vacuum compressed optical field generator are provided to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for improving the stability of a vacuum compressed light field generator. By analyzing the noise of the interference signal, the stability problem can be accurately located, and then the high-precision stable control of the vacuum compressed light field generator can be achieved by optimizing the parameters of the servo control system.

[0007] To achieve the above objectives, the present invention provides a method for improving the stability of a vacuum-compressed optical field generator, comprising the following steps: S1: Acquire optical signals, convert them into electrical signals, and input them into the negative feedback servo control system; S2: Lock the cavity length of the vacuum compressed light field generator according to the electrical signal input in S1; S3: In step S2, seed light is input into the vacuum compressed state light field generator. The power of the seed light transmitted by the vacuum compressed state light field generator is the same as the power of the local light. The local light and the transmitted seed light are coupled and interfere. S4: Adjust the driving voltage to control the relative phase between the local light and the transmitted seed light in S3, so that the local light and the transmitted seed light will undergo constructive interference. S5: Detect the constructive interference optical signal obtained in step S4, output a DC signal and the corresponding real-time spectrum, analyze the real-time spectrum, and identify the technical noise carried. S6: Optimize the pressure parameters of the air flotation platform, optimize the parameters of the negative feedback servo control system, and minimize the noise amplitude in the spectrum characteristics.

[0008] Preferably, in S1, the reflected pump light of the vacuum compressed state light field generator is used as an optical feedback signal, and the optical feedback signal is converted into an error electrical signal by a third photodetector, and the error electrical signal is input to the negative feedback servo control system. The negative feedback servo control system is a Pound-Drever-Hall frequency stabilization system, which includes a high-frequency signal generator, mixer, low-pass filter, low-noise power amplifier, proportional-integral controller and high-voltage amplifier.

[0009] Preferably, in S2, the negative feedback servo control system performs closed-loop negative feedback control on the cavity length of the vacuum compressed light field generator based on the error electrical signal input in S1. The negative feedback servo control system achieves precise adjustment of the cavity length by driving the piezoelectric ceramic in the vacuum compressed light field generator, thereby locking the cavity length of the vacuum compressed light field generator.

[0010] Preferably, S3 specifically includes the following steps: S31: Inject the seed light into the vacuum compressed state light field generator so that the seed light resonates with the vacuum compressed state light field generator; S32: Adjust the seed light power transmitted from the vacuum compressed light field generator so that the transmitted seed light power is the same as the local light power; S33: Adjust the beam parameters of the local light by using an adjustable beam expander to match the spot size and pattern of the transmitted seed light with that of the local light; S34: The local light and the transmitted seed light, which are matched in power and mode, are coupled together by the fourth beam splitter to cause interference.

[0011] Preferably, in S4, the driving voltage loaded on the piezoelectric ceramic of the third reflecting mirror is adjusted to precisely control the relative phase between the local light and the transmitted seed light in S3, and the relative phase difference is adjusted to an even multiple of π so that the two beams of light undergo constructive interference.

[0012] Preferably, S5 specifically includes the following steps: S51: The constructive interference optical signal obtained in S4 is detected by the second photodetector, converted into an electrical signal, and then monitored by a Fourier real-time analysis oscilloscope. S52: The Fourier real-time analysis oscilloscope synchronously acquires and displays the DC signal output from S51 and the corresponding real-time spectrum; S53: Analyze the real-time spectral characteristics to identify additional technical noise carried in the optical signal.

[0013] Preferably, S6 specifically refers to optimizing the air flotation pressure of the experimental platform, optimizing the main parameters in the negative feedback servo control system, and minimizing the noise amplitude in the spectral characteristics; Key parameters include the signal gain, PI bandwidth, and low-frequency gain of the proportional-integral controller, as well as the gain and bias of the high-voltage amplifier.

[0014] A device for improving the stability of a vacuum compressed state optical field generator is applied to a method for improving the stability of a vacuum compressed state optical field generator: It includes an all-solid-state laser and a frequency doubler disposed on the left and right sides of a first beam splitter; a second beam splitter disposed on the other side of the frequency doubler; a third beam splitter disposed between the second beam splitter and the vacuum compressed state optical field generator; the second and third beam splitters are symmetrically arranged; a third photodetector is disposed above the third beam splitter; a negative feedback servo control system is disposed above the third photodetector and the vacuum compressed state optical field generator; a fourth beam splitter is disposed between the vacuum compressed state optical field generator and the second photodetector; a first photodetector and a third reflector are disposed on the upper and lower sides of the fourth beam splitter, respectively; and a Fourier real-time analysis oscilloscope is disposed on the other side of the second photodetector. The all-solid-state laser, the first beam splitter, the frequency doubler, the second beam splitter, the third beam splitter, the vacuum compressed state light field generator, the fourth beam splitter, and the second photodetector are all positioned on the same horizontal line.

[0015] Preferably, a second reflector is disposed on one side of the third reflector, a fifth beam splitter is disposed between the second reflector and the first beam splitter, a first reflector is disposed on one side of the fifth beam splitter, and the first reflector and the second beam splitter are disposed on the same vertical line.

[0016] Preferably, the third reflecting mirror is provided with piezoelectric ceramic.

[0017] Therefore, the device and method for improving the stability of a vacuum compressed optical field generator using the above-described structure have the following beneficial effects: (1) This invention captures low-frequency cavity length jitter in a vacuum compressed state optical field generator in real time through spectrum analysis of laser interference signals, solving the problem of locking but not monitoring, and providing a precise basis for adjusting key parameters in a negative feedback servo control system.

[0018] (2) The optical path and circuit design of this invention are compatible with most vacuum compressed state light field generators and can be easily promoted in experimental systems for preparing such vacuum compressed state light fields.

[0019] (3) The present invention optimizes the pressure parameters of the experimental air flotation platform and minimizes the noise amplitude in the spectrum characteristics by adjusting the signal gain, PI bandwidth, low-frequency gain of the proportional-integral controller in the negative feedback servo control system, as well as the gain and bias of the high-voltage amplifier, thereby improving the stability of the vacuum compressed state light field generator.

[0020] The method of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a diagram of a device for improving the stability of a vacuum compressed optical field generator according to the present invention; Figure 2 This is a flowchart illustrating how the stability of a vacuum-compressed optical field generator can be improved according to the present invention; Figure 3 This is a spectrum curve of the laser interference signal collected during the implementation of this invention; Figure 4 This is a spectrum curve obtained after optimizing the key parameters in the negative feedback servo control system in the embodiment of the invention. Attached Figure Description

[0023] 1. All-solid-state laser; 2. First beam splitter; 3. Frequency doubler; 4. Second beam splitter; 5. Third beam splitter; 6. Vacuum compressed state light field generator; 7. Fourth beam splitter; 8. First photodetector; 9. Second photodetector; 10. Fourier real-time analysis oscilloscope; 11. Third photodetector; 12. Negative feedback servo control system; 13. Fifth beam splitter; 14. First mirror; 15. Second mirror; 16. Third mirror. Detailed Implementation

[0024] The method of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the methodological or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0026] The terms "comprising" or "including" as used in this invention mean that the element preceding the term encompasses the element listed after the term, and do not exclude the possibility of encompassing other elements. Terms such as "inner," "outer," "upper," and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In this invention, unless otherwise explicitly specified and limited, the term "attached" and similar terms should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Example like Figure 1 As shown, a device for improving the stability of a vacuum compressed state optical field generator is applied to a method for improving the stability of a vacuum compressed state optical field generator: it includes an all-solid-state laser 1 and a frequency doubler 3 disposed on the left and right sides of a first beam splitter 2, a second beam splitter 4 disposed on the other side of the frequency doubler 3, a third beam splitter 5 disposed between the second beam splitter 4 and the vacuum compressed state optical field generator 6, the second beam splitter 4 and the third beam splitter 5 being symmetrically disposed, a third photodetector 11 disposed above the third beam splitter 5, a negative feedback servo control system 12 disposed above the third photodetector 11 and the vacuum compressed state optical field generator 6, a fourth beam splitter 7 disposed between the vacuum compressed state optical field generator 6 and the second photodetector 9, a first photodetector 8 and a third reflector 16 disposed on the upper and lower sides of the fourth beam splitter 7 respectively, and a Fourier real-time analysis oscilloscope 10 disposed on the other side of the second photodetector 9; The all-solid-state laser 1, the first beam splitter 2, the frequency doubler 3, the second beam splitter 4, the third beam splitter 5, the vacuum compressed state light field generator 6, the fourth beam splitter 7, and the second photodetector 9 are all arranged on the same horizontal line.

[0028] A piezoelectric ceramic is provided on the third reflector 16. A second reflector 15 is provided on one side of the third reflector 16. A fifth beam splitter 13 is provided between the second reflector 15 and the first beam splitter 2. A first reflector 14 is provided on one side of the fifth beam splitter 13. The first reflector 14 and the second beam splitter 4 are arranged on the same vertical line.

[0029] The laser output from the all-solid-state laser 1 is transmitted through the first beam splitter 2 and injected into the frequency doubler 3. The frequency doubled light output from the frequency doubler 3 passes sequentially through the second beam splitter 4 and the third beam splitter 5 and is injected into the vacuum compressed state light field generator 6. This injected light is the pump light of the vacuum compressed state light field generator 6. The reflected light from the first beam splitter 2 passes through the fifth beam splitter 13, the first reflector 14, the second beam splitter 4, and the third beam splitter 5 and is injected into the vacuum compressed state light field generator 6. This injected light is the seed light of the vacuum compressed state light field generator 6. The transmitted light from the fifth beam splitter 13 passes sequentially through the second reflector 15 and the third reflector 16 and reaches the fourth beam splitter 7. This beam is the local light.

[0030] The local light and the transmitted seed light from the vacuum-compressed light field generator 6 are coupled through the fourth beam splitter 7. The reflected signal from the fourth beam splitter 7 enters the first photodetector 8, and the transmitted signal from the fourth beam splitter 7 enters the second photodetector 9. The output signal of the second photodetector 9 is connected to the Fourier real-time analysis oscilloscope 10. The reflected pump light from the vacuum-compressed light field generator 6 is reflected by the third beam splitter 5 and enters the third photodetector 11. The output signal of the third photodetector 11 enters the negative feedback servo control system 12, and the output of the negative feedback servo control system 12 is connected to the vacuum-compressed light field generator 6.

[0031] The all-solid-state laser 1 has an output power of 6W and a center wavelength of 1064nm; the frequency multiplier 3 has an output power of 1.2W and a center wavelength of 532nm, uses an LBO nonlinear crystal, and operates at a temperature of 149℃; the vacuum compressed state optical field generator 6 has a semi-monolithic cavity structure, uses a PPKTP nonlinear crystal, and operates at a temperature of 34℃; the fourth beam splitter 7 is a 50 / 50 beam splitter; the first photodetector 8 and the second photodetector 9 are a pair of balanced detectors made in the laboratory; the Fourier real-time analysis oscilloscope 10 is a Rigol DHO4204 oscilloscope; the negative feedback servo control system 12 is a Pound-Drever-Hall frequency stabilization system, which includes a high-frequency signal generator, a mixer, a low-pass filter, a low-noise power amplifier, a proportional-integral controller, and a high-voltage amplifier.

[0032] like Figure 2 As shown, a method for improving the stability of a vacuum-compressed optical field generator includes the following steps: S1: Acquire optical signals, convert optical signals into electrical signals, and input them to the negative feedback servo control system; In S1, the reflected pump light of the vacuum compressed state optical field generator is used as the optical feedback signal, and the optical feedback signal is converted into an error electrical signal by the third photodetector, and the error electrical signal is input to the negative feedback servo control system; The negative feedback servo control system is a Pound-Drever-Hall frequency stabilization system, which includes a high-frequency signal generator, mixer, low-pass filter, low-noise power amplifier, proportional-integral controller and high-voltage amplifier.

[0033] S2: The cavity length of the vacuum-compressed optical field generator is locked based on the electrical signal input in S1. In S2, the negative feedback servo control system performs closed-loop negative feedback control on the cavity length of the vacuum-compressed optical field generator based on the error electrical signal input in S1. The negative feedback servo control system achieves precise adjustment of the cavity length by driving the piezoelectric ceramic inside the vacuum-compressed optical field generator, locking the cavity length and ensuring stable operation of the vacuum-compressed optical field generator. The cavity length locking parameters include a modulation frequency of 21MHz, a modulation amplitude of 5V; a proportional-integral controller signal gain of 5.6 times, a PI bandwidth of 30kHz, and a low-frequency gain of 20dB; and a high-voltage amplifier bias of 236V.

[0034] S3: In step S2, seed light is input into the vacuum-compressed optical field generator. The power of the seed light transmitted by the vacuum-compressed optical field generator is the same as the power of the local light, and the local light and the transmitted seed light couple and interfere. S3 specifically includes the following steps: S31: Inject the seed light into the vacuum compressed state light field generator so that the seed light resonates with the vacuum compressed state light field generator; S32: Adjust the seed light power transmitted from the vacuum compressed light field generator so that the transmitted seed light power is the same as the local light power. In the experiment, both beams of light were 1.5mW. S33: The beam parameters of the local light are adjusted by an adjustable beam expander to match the spot size and mode of the transmitted seed light with the local light. The mode matching efficiency was approximately 98.5% in the experiment. S34: The local light and the transmitted seed light, which are matched in power and mode, are coupled together by the fourth beam splitter to cause interference.

[0035] S4: Adjust the driving voltage to control the relative phase between the local light and the transmitted seed light in S3, so that the local light and the transmitted seed light will undergo constructive interference; in S4, adjust the driving voltage loaded on the piezoelectric ceramic of the third reflecting mirror to precisely control the relative phase between the local light and the transmitted seed light in S3, adjust the relative phase difference to an even multiple of π, so that the two beams of light will undergo constructive interference.

[0036] S5: Detect the constructive interference optical signal obtained in step S4, output a DC signal and its corresponding real-time spectrum, analyze the real-time spectrum, and identify the carried technical noise; S5 specifically includes the following steps: S51: The constructive interference optical signal obtained in S4 is detected by the second photodetector, converted into an electrical signal, and then monitored by a Fourier real-time analysis oscilloscope. S52: The Fourier real-time analysis oscilloscope synchronously acquires and displays the DC signal output from S51 and the corresponding real-time spectrum; S53: Analyze the real-time spectral characteristics to identify additional technical noise carried in the optical signal; such as Figure 3 As shown, the optical signal carries considerable additional technical noise. For example, sharp noise with amplitudes greater than 800mV is present at the analysis frequencies of 50Hz and 150Hz; noise is also present at other multiples of 50Hz; a noise cluster with an amplitude of approximately 200mV is present near the analysis frequency of 20Hz; and a noise cluster with an amplitude of approximately 150mV is present in the analysis frequency range of 120-140Hz. The sources of this noise are identified as mechanical vibration and noise introduced during the cavity locking process of the vacuum-compressed optical field generator.

[0037] S6: Optimize the air flotation platform pressure parameters and the negative feedback servo control system parameters to minimize the noise amplitude in the spectral characteristics. In S6, the air flotation pressure of the experimental platform is slightly increased from 0.7 MPa to 0.72 MPa; the main parameters in the negative feedback servo control system are optimized, including the signal gain, PI bandwidth, and low-frequency gain of the proportional-integral controller, as well as the gain and bias of the high-voltage amplifier; the signal gain of the proportional-integral controller in the negative feedback servo control system is adjusted by 4.2 times, and the low-frequency error signal gain is adjusted by 30 dB. The spectral curves acquired after parameter optimization are shown below. Figure 4 As shown, the amplitude of sharp noise at the analysis frequencies of 50Hz and 150Hz decreased from about 800mV to about 15mW; the noise clusters at the analysis frequencies of 120-140Hz were completely removed; and the noise amplitudes at other frequencies were reduced.

[0038] Therefore, the present invention employs the above-mentioned device and method for improving the stability of a vacuum compressed light field generator. By combining real-time monitoring of laser interference signals with parameter adjustment of the servo control system, the stability problem of the vacuum compressed light field generator can be accurately located, and its working stability can be significantly improved through parameter optimization.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the method of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the method of the present invention, and these modifications or equivalent substitutions should not cause the modified method to deviate from the spirit and scope of the method of the present invention.

Claims

1. A device for improving the stability of a vacuum-compressed optical field generator, characterized in that: The system includes all-solid-state lasers and frequency doublers positioned on either side of a first beam splitter. A second beam splitter is positioned on the other side of the frequency doubler. A third beam splitter is positioned between the second beam splitter and a vacuum-compressed light field generator. The second and third beam splitters are symmetrically positioned. A third photodetector is positioned above the third beam splitter. A negative feedback servo control system is positioned above the third photodetector and the vacuum-compressed light field generator. A fourth beam splitter is positioned between the vacuum-compressed light field generator and the second photodetector. A first photodetector and a third reflector are positioned on the upper and lower sides of the fourth beam splitter, respectively. A Fourier real-time analysis oscilloscope is positioned on the other side of the second photodetector. A second reflector is provided on one side of the third reflector, a fifth beam splitter is provided between the second reflector and the first beam splitter, a first reflector is provided on one side of the fifth beam splitter, and the first reflector and the second beam splitter are provided on the same vertical line. The negative feedback servo control system is a Pound-Drever-Hall frequency stabilization system, which includes a high-frequency signal generator, mixer, low-pass filter, low-noise power amplifier, proportional-integral controller and high-voltage amplifier; The all-solid-state laser, the first beam splitter, the frequency doubler, the second beam splitter, the third beam splitter, the vacuum compressed state light field generator, the fourth beam splitter, and the second photodetector are all arranged on the same horizontal line. The laser output from the all-solid-state laser is transmitted through the first beam splitter and then injected into the frequency doubler. The frequency-doubled light output from the frequency doubler passes sequentially through the second and third beam splitters and is injected into the vacuum-compressed state optical field generator. This injected light serves as the pump light for the vacuum-compressed state optical field generator. The reflected light from the first beam splitter passes through the fifth beam splitter, the first reflecting mirror, the second beam splitter, and the third beam splitter and is injected into the vacuum-compressed state optical field generator. This injected light serves as the seed light for the vacuum-compressed state optical field generator. The transmitted light from the fifth beam splitter passes sequentially through the second and third reflecting mirrors and reaches the fourth beam splitter. This beam is the local light. The outputs of the local light and the vacuum compressed light field generator are coupled through a fourth beam splitter. The reflected signal from the fourth beam splitter enters the first photodetector, and the transmitted signal from the fourth beam splitter enters the second photodetector. The output signal of the second photodetector is connected to a Fourier real-time analysis oscilloscope. The reflected pump light from the vacuum compressed light field generator is reflected by a third beam splitter and enters the third photodetector. The output signal of the third photodetector enters the negative feedback servo control system, and the output of the negative feedback servo control system is connected to the vacuum compressed light field generator.

2. The device for improving the stability of a vacuum compressed optical field generator according to claim 1, characterized in that, The third reflecting mirror is equipped with piezoelectric ceramics.

3. A method for improving the stability of a vacuum compressed state light field generator, applied to a device for improving the stability of a vacuum compressed state light field generator as described in any one of claims 1-2, characterized in that: Includes the following steps: S1: Obtain the reflected pump light from the vacuum compressed state light field generator as an optical signal, convert the optical signal into an electrical signal, and input it to the negative feedback servo control system; S2: Lock the cavity length of the vacuum compressed light field generator according to the electrical signal input in S1; The negative feedback servo control system in S2 performs closed-loop negative feedback control on the cavity length of the vacuum compressed light field generator according to the error electrical signal input in S1. The negative feedback servo control system achieves precise adjustment of the cavity length by driving the piezoelectric ceramic in the vacuum compressed light field generator, thereby locking the cavity length of the vacuum compressed light field generator. S3: In step S2, seed light is input into the vacuum compressed state light field generator. The power of the seed light transmitted by the vacuum compressed state light field generator is the same as the power of the local light. The local light and the transmitted seed light are coupled and interfere. S4: Adjust the driving voltage loaded on the piezoelectric ceramic of the third reflecting mirror to control the relative phase between the local light and the transmitted seed light in S3, so that the local light and the transmitted seed light will undergo constructive interference. S5: Detect the constructive interference optical signal obtained in step S4, output a DC signal and the corresponding real-time spectrum, analyze the real-time spectrum, and identify the technical noise carried. S6: Optimize the pressure parameters of the air flotation platform, optimize the parameters of the negative feedback servo control system, and minimize the noise amplitude in the spectrum characteristics; Specifically, S6 means: optimizing the air flotation pressure of the experimental platform, optimizing the main parameters in the negative feedback servo control system, and minimizing the noise amplitude in the spectrum characteristics; Key parameters include the signal gain, PI bandwidth, low-frequency gain of the proportional-integral controller, and the gain and bias of the high-voltage amplifier.

4. The method for improving the stability of a vacuum-compressed optical field generator according to claim 3, characterized in that, In S1, the reflected pump light from the vacuum compressed state light field generator is used as an optical feedback signal. The optical feedback signal is converted into an error electrical signal by the third photodetector, and the error electrical signal is input to the negative feedback servo control system.

5. The method for improving the stability of a vacuum-compressed optical field generator according to claim 3, characterized in that, S3 specifically includes the following steps: S31: Inject the seed light into the vacuum compressed state light field generator so that the seed light resonates with the vacuum compressed state light field generator; S32: Adjust the seed light power transmitted from the vacuum compressed light field generator so that the transmitted seed light power is the same as the local light power; S33: Adjust the beam parameters of the local light by using an adjustable beam expander to match the spot size and pattern of the transmitted seed light with that of the local light; S34: The local light and the transmitted seed light, which are matched in power and mode, are coupled together by the fourth beam splitter to cause interference.

6. The method for improving the stability of a vacuum-compressed optical field generator according to claim 3, characterized in that, In S4, the relative phase between the local light and the transmitted seed light in S3 is precisely controlled, and the relative phase difference is adjusted to an even multiple of π, so that the two beams of light undergo constructive interference.

7. The method for improving the stability of a vacuum-compressed optical field generator according to claim 3, characterized in that, S5 specifically includes the following steps: S51: The second photodetector is used to detect the constructive interference light signal obtained in S4. After the interference light signal is converted into an electrical signal, it is monitored by a Fourier real-time analysis oscilloscope. S52: The Fourier real-time analysis oscilloscope synchronously acquires and displays the DC signal output from S51 and the corresponding real-time spectrum; S53: Analyze the real-time spectral characteristics to identify additional technical noise carried in the optical signal.

Images