Far infrared photoelectric detector weak signal test system based on two-stage refrigeration

Abstract

The invention relates to a far infrared photoelectric detector weak signal test system, which comprises a low-temperature refrigeration system, a first-stage cold head is connected with a vacuum Dewar and a low-temperature cold screen and maintains a low-temperature environment of the vacuum Dewar and the low-temperature cold screen, and a second-stage cold head cools an objective table and a detector to reduce thermal noise of the detector; the low-temperature cold shield wraps the secondary cold head and the objective table to form a thermal isolation layer, and external thermal radiation is blocked; a broadband far infrared optical filter is integrated at the position, right facing the objective table, of the low-temperature cold screen; according to the radiation source module, a vacuum Dewar is provided with an optical window; a blackbody radiation source is arranged right opposite to the optical window, and a radiation field is formed on the photosensitive surface of the detector at the objective table after the blackbody radiation source passes through the optical window and the broadband far infrared optical filter; according to the signal transmission link, the objective table is connected with the detector through a signal transmission cable; and a signal passes through the low-temperature cold shield and the vacuum Dewar and is connected to an upper computer. According to the invention, high performance, miniaturization and universality of far infrared weak signal testing are realized, and dependence on special facilities is broken through.

Description

Technical Field

[0001] The invention belongs to the field of infrared photoelectric detectors, and specifically relates to a corresponding test system for far-infrared photoelectric detectors, and especially relates to a weak signal test system for very long-wave band far-infrared photoelectric detectors. Background Art

[0002] Very long-wavelength far-infrared (VLWFID) photodetectors are photodetectors operating in the far-infrared to terahertz range, typically with wavelengths of 30–1000 μm and corresponding frequencies of 0.3–10 THz. This wavelength range lies in the transition region between microwaves and the mid-infrared in the electromagnetic spectrum. VLWFIDs have important applications in deep space exploration, climate monitoring, and astronomical observations. Their high sensitivity to low-temperature radiation sources has made them a research hotspot. However, due to the weak VLW signals and their susceptibility to thermal noise and environmental interference, detector performance testing and calibration present significant challenges. Radiation test systems simulate standardized radiation environments to evaluate key detector performance parameters, including sensitivity, noise-equivalent power, and spectral response. These systems typically include a blackbody radiation source, temperature control, optical components, a detector test module, and a data processing module, working together to achieve high-precision testing and calibration.

[0003] Existing signal testing systems for far-infrared photodetectors often have the following limitations: First, due to the extremely low radiation power in the very long wave band, existing blackbody radiation sources have difficulty maintaining sufficient radiation efficiency at extremely low temperatures, resulting in insufficient intensity of the simulated signal and affecting test accuracy. Second, the system's temperature control stability and uniformity are limited, and small temperature fluctuations can introduce significant errors, especially when testing highly sensitive detectors. Third, thermal noise, background radiation, and mechanical vibrations in the laboratory environment can further interfere with signal stability and reduce the signal-to-noise ratio. Existing systems have not yet reached ideal levels in terms of shielding environmental interference and suppressing system background noise. These limitations pose a challenge to the accurate simulation of weak signals and the performance testing of highly sensitive detectors, and there is an urgent need for the introduction of new technologies to improve system performance.

[0004] Therefore, how to solve the technical problems of insufficient blackbody radiation efficiency, poor temperature control stability and weak environmental interference suppression of traditional systems at extremely low temperatures, and provide a very long wave far infrared detector test system based on conventional blackbody and noise suppression technology are technical problems that need to be urgently solved by technical personnel in this field. Summary of the Invention

[0005] The purpose of the present invention is to provide a far-infrared photoelectric detector weak signal testing system to solve the problems in the prior art.

[0006] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0007] A far-infrared photoelectric detector weak signal testing system, characterized by comprising:

[0008] Low temperature refrigeration system:

[0009] The first-stage cold head connects the vacuum dewar and the cryogenic cold shield and maintains a low-temperature environment for both. The second-stage cold head cools the stage and detector to reduce the thermal noise of the detector.

[0010] Thermal Noise Suppression Components:

[0011] The low-temperature cold shield wraps the secondary cold head and the stage to form a thermal isolation layer to block external heat radiation;

[0012] The low-temperature cold screen is directly opposite to the stage and is integrated with a wide-band far-infrared filter;

[0013] Radiation source module:

[0014] An optical window is provided on the vacuum dewar;

[0015] A blackbody radiation source is set opposite the optical window, and a radiation field is formed on the photosensitive surface of the detector on the stage after passing through the optical window and the wide-band far-infrared filter;

[0016] Signal transmission link:

[0017] The stage is connected to the detector via a signal transmission cable;

[0018] The signal passes through the cryogenic cold shield and vacuum dewar and is connected to the host computer.

[0019] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0020] As a preferred technical solution of the present invention: the low-temperature refrigeration system uses a two-stage GM refrigerator, a two-stage GM pulse tube refrigerator, a two-stage Stirling refrigerator or a two-stage Stirling pulse tube refrigerator.

[0021] As a preferred technical solution of the present invention: the first-stage cold head and the low-temperature cold shield are placed together in a vacuum dewar to perform system-level packaging to achieve the vacuum degree and stability of the system.

[0022] As a preferred technical solution of the present invention: the secondary cold head and the stage are both placed in a low-temperature cold shield to reduce heat leakage loss.

[0023] As a preferred technical solution of the present invention: an optical window is provided on the vacuum dewar opposite to the wide-band far-infrared filter, a black body is provided opposite to the optical window, and the wide-band far-infrared filter is used as the core optical element. The infrared signal emitted by the black body radiation passes through the optical window and the wide-band far-infrared filter in sequence, and finally forms a radiation field with clear spectral characteristics, which evenly covers the photosensitive surface of the low-temperature detector on the stage.

[0024] As a preferred technical solution of the present invention: a low-temperature far-infrared photodetector is placed on the stage to block impurity bands, and the stage is arranged on top of a secondary cold head. The secondary cold head provides an extremely low-temperature working environment for the low-temperature far-infrared photodetector through the stage, thereby reducing dark current and achieving noise suppression;

[0025] The operating temperature of the low-temperature far-infrared photodetector on the stage is as low as 4K.

[0026] As a preferred technical solution of the present invention: a wide-band far-infrared filter is installed on the low-temperature cold screen at a position opposite to the stage, wherein the working band of the wide-band far-infrared filter can reach 0.1-20μm and the transmittance is 0.01%-90%;

[0027] The wide-band far-infrared filter is a far-infrared filter, a neutral density filter or a continuously variable filter.

[0028] As a preferred technical solution of the present invention: the optical window is a far-infrared window, and is made of thallium bromide iodide.

[0029] As a preferred technical solution of the present invention: a signal transmission cable is connected to the stage, and the response signal and working temperature of the low-temperature far-infrared photodetector are connected to the host computer by the signal transmission cable through the low-temperature cold screen and the vacuum dewar.

[0030] As a preferred technical solution of the present invention: the low-temperature cooling screen is made of copper or aluminum alloy;

[0031] The vacuum dewar is made of aluminum alloy or stainless steel.

[0032] Compared with the prior art, the present invention's far-infrared photodetector weak signal test system has the following beneficial effects: the present invention directly realizes a 4K ultra-low temperature environment for the stage and detector through a compact two-stage refrigeration system (a primary cold head + a secondary cold head), solves the problem of the traditional blackbody source's limited minimum temperature, and does not rely on liquid helium or large-scale refrigeration facilities, thereby realizing an efficient and integrated ultra-low temperature environment. It does not rely on ultra-low temperature blackbodies, and can realize an equivalent ultra-low temperature radiation test environment. In the present invention, the problem of the test system being seriously interfered by thermal noise and background radiation is solved by combining a low-temperature cold screen with a wide-band filter, which is significant. The isolation efficiency of external thermal radiation is improved, the system thermal noise and background radiation interference are reduced, and the test signal-to-noise ratio (SNR) is greatly improved. When the energy of very long-wave infrared photons is extremely low, extremely weak signal detection is achieved through an extremely low temperature environment and high shielding efficiency. Through the coordinated design of a wide-temperature blackbody and an adjustable filter, the problem of the limited temperature range of the blackbody source and the difficulty in simulating the radiation characteristics of extremely low-temperature targets is solved. The full range of signal simulation from extremely low background radiation to high-temperature targets is achieved, meeting the test requirements of different scenarios, providing a full-temperature adjustable test method, and filling the gap that existing technologies cannot cover extremely low-temperature radiation sources.

[0033] This invention, for the first time, achieves the equivalent generation of a 4K ultra-cold radiation source without requiring an ultra-cold blackbody. This overcomes the problem of traditional test systems being unable to directly test ultra-cold detectors due to the insufficient minimum blackbody temperature (only reaching 250K). Through ultra-cold environmental control, efficient thermal shielding, and wide-temperature range radiation simulation, this invention significantly improves the accuracy and reliability of far-infrared weak signal detection. This achieves high performance, miniaturization, and universal applicability of far-infrared weak signal testing, eliminating the reliance on specialized far-infrared detectors for weak signals. This provides critical testing support for detector development in fields such as deep space exploration and quantum sensing.

[0034] The present invention provides a far-infrared photoelectric detector weak signal test system with high signal-to-noise ratio, high stability, ability to simulate weak signals, small size, simple structure and excellent test performance. The system overcomes the defects of existing far-infrared photoelectric detector signal test systems, such as low signal-to-noise ratio, poor stability, poor weak signal simulation capability, large size, complex structure, high operation difficulty and difficulty in meeting broader application needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the far-infrared photoelectric detector weak signal testing system of the present invention;

[0036] Among them, 1 is the first-level cold head, 2 is the second-level cold head, 3 is the stage, 4 is the wide-band far-infrared filter, 5 is the optical window, 6 is the black body, 7 is the signal transmission cable, 8 is the host computer, 9 is the low-temperature cold shield, and 10 is the vacuum dewar. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0038] A far-infrared photoelectric detector weak signal testing system of the present invention comprises:

[0039] Low temperature refrigeration system:

[0040] The first-stage cold head 1 connects the vacuum dewar 10 and the cryogenic cold shield 9 and maintains a low-temperature environment for both. The second-stage cold head 2 cools the stage 3 and the detector to reduce the thermal noise of the detector.

[0041] Thermal Noise Suppression Components:

[0042] The low-temperature cold shield 9 wraps the secondary cold head and the stage to form a thermal isolation layer to block external heat radiation;

[0043] The low temperature cold screen 9 is directly opposite to the stage and is integrated with a wide band far infrared filter 4;

[0044] Radiation source module:

[0045] An optical window 5 is provided on the vacuum dewar 10;

[0046] A black body radiation source 6 is arranged opposite the optical window, and a radiation field is formed on the photosensitive surface of the detector at the stage after passing through the optical window and the wide-band far-infrared filter;

[0047] Signal transmission link:

[0048] The stage 3 is connected to the detector via a signal transmission cable 7;

[0049] The signal passes through the low-temperature cold shield 9 and the vacuum dewar 10 and is connected to the host computer 8.

[0050] The low-temperature refrigeration system uses a two-stage GM refrigerator, a two-stage GM pulse tube refrigerator, a two-stage Stirling refrigerator or a two-stage Stirling pulse tube refrigerator.

[0051] The first-stage cold head 1 and the low-temperature cold shield 9 are placed together in the vacuum dewar 10 to perform system-level packaging to achieve the vacuum degree and stability of the system.

[0052] The secondary cold head 2 and the stage 3 are both placed in a low-temperature cold shield 9 to reduce heat leakage loss.

[0053] An optical window 5 is provided on the vacuum dewar 10 opposite the wide-band far-infrared filter 4, and a black body 6 is provided opposite the optical window 5. The wide-band far-infrared filter is used as the core optical element. The infrared signal emitted by the black body radiation passes through the optical window and the wide-band far-infrared filter in sequence, and finally forms a radiation field with clear spectral characteristics, which evenly covers the photosensitive surface of the low-temperature detector on the stage.

[0054] A low-temperature far-infrared photodetector is placed on the stage 3 to block impurity bands. The stage 3 is set on top of the secondary cold head 2. The secondary cold head 2 provides an extremely low-temperature working environment for the low-temperature far-infrared photodetector through the stage 3, thereby reducing dark current and achieving noise suppression.

[0055] The operating temperature of the low-temperature far-infrared photodetector on the stage 3 is as low as 4K.

[0056] A wide-band far-infrared filter 4 is installed on the low-temperature cold screen 9 facing the stage 3. The wide-band far-infrared filter 4 has an operating band of 0.1-20 μm and a transmittance of 0.01%-90%.

[0057] The wide-band far-infrared filter uses a far-infrared filter (attenuation filter), which can be a neutral density filter (attenuation filter), a continuously variable filter (attenuation filter), etc.

[0058] The optical window 5 is a far-infrared window made of thallium bromide iodide.

[0059] The stage 3 is connected to a signal transmission cable 7 , and the response signal and operating temperature of the low-temperature far-infrared photodetector are connected to the host computer 8 through the signal transmission cable 7 through the low-temperature cold shield 9 and the vacuum dewar 10 .

[0060] The low temperature cold screen 9 is made of copper or aluminum alloy;

[0061] The vacuum dewar 10 is made of aluminum alloy or stainless steel.

[0062] The wide-band far-infrared filter 4 can attenuate the radiation of the blackbody 6 to varying degrees, simulating an extremely low background radiation signal and creating an extremely low background radiation test condition to enable response testing of very long-wavelength infrared photoelectric detectors in conventional laboratories.

[0063] The operating temperature of the black body 6 can cover 200K-2000K.

[0064] The secondary cold head can provide an extremely low temperature working environment for the low-temperature far-infrared photodetector through the stage, reduce dark current, and achieve noise suppression. The blackbody temperature is adjustable over a wide range, and can provide blackbody radiation signals at different temperatures. The optical element can attenuate the blackbody radiation to different degrees, simulate extremely low background radiation signals, and create extremely low background radiation test conditions to realize the response test of very long-wave infrared photodetectors in conventional laboratories.

[0065] The present invention's far-infrared photodetector weak signal testing system features a simple overall structure, rational design, and convenient operation. A signal transmission cable is connected to the stage. The response signal and operating temperature of the low-temperature far-infrared photodetector are transmitted via the cable through a cryogenic cold shield and vacuum dewar to a host computer. Optical components are mounted on the cryogenic cold shield opposite the stage. These components are typically wide-band far-infrared filters (attenuators), but can also be neutral density filters (attenuators), continuously variable filters (attenuators), or other optical components. Optical windows are located on the vacuum dewar opposite the optical components. These are far-infrared windows made of materials such as thallium bromide iodide. Opposite the optical window is a blackbody. Blackbody radiation passes through the optical window and the optical components, evenly irradiating the low-temperature far-infrared photodetector on the stage. The operating temperature of the low-temperature far-infrared photodetector on the stage can be as low as 4K. The optical components operate in a wavelength range of 0.1-20μm, with a transmittance of 0.01%-90%. The blackbody's operating temperature ranges from 200K to 2000K. The secondary cold head provides an extremely low-temperature operating environment for the cryogenic far-infrared photodetector through the stage, reducing dark current and achieving noise suppression. The blackbody temperature is adjustable over a wide range, providing blackbody radiation signals at different temperatures. Optical components can attenuate the blackbody radiation to varying degrees, simulating extremely low background radiation signals and creating extremely low-background radiation testing conditions. This allows for response testing of very-long-wavelength infrared photodetectors in conventional laboratories, meeting a wider range of application needs and demonstrating significant application prospects.

[0066] The above invention has the following advantages or beneficial effects:

[0067] (1) Existing far-infrared photoelectric detector weak signal test systems are often large in size, complex in system, and have complex and expensive cooling systems, making it very difficult to simulate test conditions. The system designed by the present invention has a simple structure and a small size, and the system space is fully utilized, with better cooling performance, efficient use of system space and energy, and can easily realize the simulation signal test of far-infrared photoelectric detectors under conventional laboratory conditions;

[0068] (2) Due to the extremely low radiation power in the very long wave band, existing blackbody radiation sources are difficult to maintain sufficient radiation efficiency at extremely low temperatures, resulting in insufficient intensity of the analog signal, affecting the test accuracy. In addition, the temperature control stability and uniformity of the system are limited, and small temperature fluctuations may introduce significant errors, which is particularly evident when testing high-sensitivity detectors. However, the present invention can use a room temperature blackbody, which can not only ensure the radiation efficiency of the blackbody radiation source, but also does not affect the temperature stability and uniformity of the system, and can easily achieve extreme test conditions;

[0069] (3) The existing system has not yet reached the ideal level in terms of shielding environmental interference and suppressing system background noise. Thermal noise, background radiation and mechanical vibration in the laboratory environment will further interfere with the stability of the signal and reduce the signal-to-noise ratio. However, due to the setting of optical elements, the background radiation and thermal noise of the present invention are greatly attenuated. In addition, due to the simplicity of the technical solution, the system structure can be greatly simplified, which greatly improves the stability of the system and can significantly improve the signal-to-noise ratio of device testing.

[0070] In summary, the present invention has very positive significance for the application of the far-infrared photoelectric detector weak signal test system in special fields such as far-infrared photoelectric detector signal testing. It greatly reduces the volume of the far-infrared photoelectric detector weak signal test system, has a more streamlined structure and can simulate extreme test conditions, realizing testing under conventional laboratory conditions, and has great application prospects.

[0071] Example 1

[0072] like Figure 1 As shown, a far-infrared photoelectric detector weak signal test system of the present invention includes a low-temperature refrigeration system, a stage 3, a wide-band far-infrared filter 4, an optical window 5, a signal transmission cable 7, a black body 6, a low-temperature cold shield 9 and a vacuum dewar 10;

[0073] The low-temperature refrigeration system mainly includes a primary cold head 1 and a secondary cold head 2, which provide two-stage refrigeration respectively and adopt a two-stage GM refrigerator;

[0074] A low-temperature far-infrared photodetector is placed on the stage 3 , which adopts an impurity-blocking band BIB detector. The stage 3 is set on the top of the secondary cold head 2 .

[0075] The secondary cold head 2 and the stage 3 are both placed in a low-temperature cooling shield 9 to reduce heat leakage loss. The low-temperature cooling shield 9 is made of aluminum alloy.

[0076] The first-stage cold head 1 and the low-temperature cold shield 9 are placed together in the vacuum dewar 10 for system-level packaging and to ensure the vacuum degree and stability of the system. The vacuum dewar 10 is made of stainless steel.

[0077] A signal transmission cable 7 is connected to the stage 3 , and the response signal and working temperature of the impurity blocking band BIB detector are connected to the host computer 8 by the signal transmission cable 7 through the low-temperature cold shield 9 and the vacuum dewar 10.

[0078] A wide-band far-infrared filter 4 is installed on the low-temperature cold shield 9 opposite the stage 3. The wide-band far-infrared filter 4 is a neutral density filter with an operating band of 2-14 μm and a transmittance of 0.1%.

[0079] An optical window 5 is provided on the vacuum dewar 10 at a position opposite to the wide-band far-infrared filter 4. The optical window 5 is a thallium bromide iodide far-infrared window.

[0080] A black body 6 is provided opposite the optical window 5 , and the operating temperature of the black body 6 is 200K-500K. The radiation of the black body 6 passes through the optical window 5 and the wide-band far-infrared filter 4 and can be evenly irradiated on the impurity blocking band BIB detector on the stage 3 .

[0081] After the system is powered on, the secondary cold head 2 provides an extremely low-temperature operating environment for the BIB detector via the stage 3, reducing dark current and achieving noise suppression. Once the operating temperature of the BIB detector on the stage 3 drops to 4K, the temperature of the blackbody 6 is regulated, with tests performed at 50K intervals between 200-500K to provide blackbody radiation signals at different temperatures. The radiation from the blackbody 6 is attenuated to a certain extent by the wide-band far-infrared filter 4, simulating an extremely low background radiation signal of the corresponding radiation value. The response voltage of the BIB infrared detector at each temperature is read and recorded in real time on the host computer, thereby enabling low-background long-wave response testing of the BIB detector in a conventional laboratory.

[0082] It has been verified that the far-infrared photodetector weak signal test system of the present invention has a simple overall structure but a reasonable design and small size. The system space is fully utilized, the cooling performance is better, the system space and energy can be efficiently utilized, and the analog signal test of the far-infrared photodetector under conventional laboratory conditions can be easily realized; the secondary cold head can provide an extremely low temperature working environment for the low-temperature far-infrared photodetector through the stage, and the working temperature of the low-temperature far-infrared photodetector on the stage can be as low as 4K; the working band of the optical element can reach 0.1-20μm, and the transmittance is 0.01%-90%; the working temperature of the blackbody can cover 200K-2000K; the blackbody temperature is adjustable over a wide range, and can provide blackbody radiation signals at different temperatures. The optical element can attenuate the blackbody radiation to different degrees, simulate extremely low background radiation signals, reduce dark current, achieve noise suppression, and create extremely low background radiation test conditions to realize the response test of very long-wave infrared photodetectors in conventional laboratories, thereby meeting broader application needs and having great application prospects.

[0083] The above-mentioned specific implementation methods are used to illustrate the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit of the present invention and the scope of protection of the claims shall fall within the scope of protection of the present invention.

Claims

1. A far-infrared photoelectric detector weak signal test system, characterized in that: include: Low temperature refrigeration system: The first-stage cold head connects the vacuum dewar and the cryogenic cold shield and maintains a low-temperature environment for both. The second-stage cold head cools the stage and detector to reduce the thermal noise of the detector. Thermal Noise Suppression Components: The low-temperature cold shield wraps the secondary cold head and the stage to form a thermal isolation layer to block external heat radiation; The low-temperature cold screen is directly opposite to the stage and is integrated with a wide-band far-infrared filter; Radiation source module: An optical window is provided on the vacuum dewar; A blackbody radiation source is set opposite the optical window, and a radiation field is formed on the photosensitive surface of the detector on the stage after passing through the optical window and the wide-band far-infrared filter; Signal transmission link: The stage is connected to the detector via a signal transmission cable; The signal passes through the cryogenic cold shield and vacuum dewar and is connected to the host computer.

2. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: The low-temperature refrigeration system uses a two-stage GM refrigerator, a two-stage GM pulse tube refrigerator, a two-stage Stirling refrigerator or a two-stage Stirling pulse tube refrigerator.

3. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: The first-stage cold head and the low-temperature cold shield are placed together in a vacuum dewar for system-level packaging to achieve the vacuum degree and stability of the system.

4. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: The secondary cold head and the stage are both placed in a low-temperature cold shield to reduce heat leakage loss.

5. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: An optical window is provided on the vacuum dewar opposite the wide-band far-infrared filter, a black body is provided opposite the optical window, and the wide-band far-infrared filter is used as the core optical element. The infrared signal emitted by the black body radiation passes through the optical window and the wide-band far-infrared filter in sequence, and finally forms a radiation field with clear spectral characteristics, which evenly covers the photosensitive surface of the low-temperature detector on the stage.

6. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: A low-temperature far-infrared photodetector is placed on the stage, and the stage is arranged on top of a secondary cold head. The secondary cold head provides an extremely low-temperature working environment for the low-temperature far-infrared photodetector through the stage, thereby reducing dark current and achieving noise suppression; The operating temperature of the low-temperature far-infrared photodetector on the stage is as low as 4K.

7. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: A wide-band far-infrared filter is installed on the low-temperature cold screen at a position opposite to the stage. The working band of the wide-band far-infrared filter can reach 0.1-20μm, and the transmittance is 0.01%-90%; The wide-band far-infrared filter is a far-infrared filter, a neutral density filter or a continuously variable filter.

8. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: The optical window is a far-infrared window made of thallium bromide iodide.

9. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: The stage is connected with a signal transmission cable, and the response signal and working temperature of the low-temperature far-infrared photoelectric detector are connected to the host computer through the signal transmission cable through the low-temperature cold screen and the vacuum dewar.

10. The far-infrared photoelectric detector weak signal testing system according to claim 1, characterized in that: Low temperature cold screen is made of copper or aluminum alloy; The vacuum dewar is made of aluminum alloy or stainless steel.

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