A response rate measuring device and method for mid-infrared detectors

Abstract

The application discloses a response rate measuring device and method for a mid-infrared detector, and solves the problem of inaccurate measurement of the actual power density of the incident detector due to the change of the response rate with temperature and / or the small photosensitive surface of the detector in the response rate calibration of the mid-infrared detector. The total power of the measuring laser can be measured by using a laser power meter, the ratio of the central spot power to the total spot power of the incident photosensitive surface of the detector can be measured by using a spot analyzer, and then the power density value of the incident photosensitive surface of the detector can be accurately measured and calculated, so that the measurement accuracy of the response rate of the mid-infrared detector is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a mid-infrared detector, in particular to a responsivity measuring device and method for a mid-infrared detector. BACKGROUND

[0002] With the rapid development of infrared laser detection technology, mid-infrared detectors have been widely used in the field of mid-infrared photoelectric detection, especially in the measurement of laser parameters. The mid-infrared detector converts the optical signal to realize the measurement of the laser output power, spot distribution, beam quality and other parameters. Responsivity is an important performance parameter of the mid-infrared detector, which is the ratio of the signal generated by the detector to the incident light power at a specific wavelength, reflecting the sensitivity and detection accuracy of the device. However, the mid-infrared detector is sensitive to temperature, and the responsivity changes with temperature, which directly affects the accuracy of the laser parameter measurement results.

[0003] Currently, there are two international standard test methods for the responsivity of mid-infrared detectors:

[0004] ① Use a blackbody as a radiation source, and calculate the power density incident on the detector directly by the blackbody radiation formula. The advantage of this method is that the blackbody is a stable radiation source, and the responsivity test has high accuracy. However, when the blackbody is a wide-spectrum radiation source, it is not possible to accurately measure the responsivity at a specific wavelength.

[0005] ② Use a laser as a radiation source, and measure the power density incident on the detector by a trap detector and a low-temperature radiometer. This method is costly and complex to operate.

[0006] In addition, both methods are limited by temperature drift. When the mid-infrared detector is irradiated by incident light, the temperature of the detector changes instantaneously, and the responsivity changes with temperature, so the accuracy cannot be improved.

[0007] The patent "Calibration device for responsivity of mid-infrared detector changing with temperature" with publication number CN 102305663A controls the temperature of the detector by a high-low temperature control box, and tests the responsivity of the detector by using a blackbody and a filter. This method lacks real-time monitoring of the temperature of the light-sensitive surface of the detector, and requires a long time for temperature control to ensure that the temperature in the high-low temperature control box reaches thermal equilibrium, resulting in low measurement efficiency.

[0008] The patent "Infrared detector room temperature response parameter test method and system" with publication number CN 116295870A uses two light sources to irradiate simultaneously, and calculates the responsivity, linear dynamic range and saturation threshold of the measured detector. This method can only measure the response parameters of the detector at room temperature, and cannot measure the response parameters in a wide temperature range, which has certain limitations. SUMMARY

[0009] In order to solve the technical problems that the response rate changes with temperature and / or the power density measurement of the actual incident detector is inaccurate when the response rate of the mid-infrared detector is calibrated, the application provides a response rate measurement device and method for a mid-infrared detector.

[0010] In order to achieve the above-mentioned purpose, the application adopts the following technical solutions:

[0011] A response rate measurement device for a mid-infrared detector, the mid-infrared detector comprising a Pt thin film resistor, a detector photosensitive surface, a detector electrode, a Pt resistor electrode and a common electrode; one end of the Pt thin film resistor is connected with the Pt resistor electrode, and the other end is connected with the common electrode; the common electrode and the detector electrode are both in contact with the detector photosensitive surface; the common electrode and the detector electrode constitute an output end of the mid-infrared detector.

[0012] The special features are:

[0013] The device comprises a laser, a vacuum cavity, a current amplifier, a collection card, a laser power meter, a light spot analyzer and a processing unit.

[0014] The laser is used to emit measurement laser to the mid-infrared detector to be measured.

[0015] The vacuum cavity is provided with a light window corresponding to the measurement laser on the side wall, and the inside of the vacuum cavity is used to set the mid-infrared detector to be measured, so that the detector photosensitive surface corresponds to the light window.

[0016] The input end of the current amplifier is used to connect with the output end of the mid-infrared detector to be measured, so as to convert the current signal output by the mid-infrared detector to be measured into a voltage signal and amplify it.

[0017] The input end of the collection card is connected with the output end of the current amplifier, and is used to collect the voltage signal output by the current amplifier.

[0018] The laser power meter is used to measure the laser power of the measurement laser.

[0019] The light spot analyzer is used to measure the light spot shape of the measurement laser.

[0020] The processing unit is connected with the output end of the collection card, and is used to calculate the response rate of the mid-infrared detector to be measured according to the current signal, the laser power and the light spot shape.

[0021] Further, a temperature control unit is further included.

[0022] The working end of the temperature control unit is connected with the vacuum cavity, and is used to control the temperature in the vacuum cavity.

[0023] Further, the temperature control unit comprises a temperature controller, a heating / cooling machine and a temperature detector.

[0024] The control end of the temperature controller is connected with the input end of the heating / cooling machine, for controlling the heating / cooling machine to heat or cool.

[0025] The heating / cooling end of the heating / cooling machine is connected with the vacuum cavity, for heating or cooling the vacuum cavity.

[0026] The temperature detector is arranged in the vacuum cavity, and the output end of the temperature detector is connected with the input end of the temperature controller, for feeding back the temperature in the vacuum cavity to the temperature controller in real time.

[0027] Further, an electric resistance measuring unit is further included.

[0028] The measuring end of the electric resistance measuring unit is connected with the Pt electric resistance electrode and the common electrode, and the output end of the electric resistance measuring unit is connected with the processing unit, for monitoring the resistance value of the Pt thin film electric resistance in real time and sending the resistance value to the processing unit.

[0029] Further, an attenuating sheet is further included.

[0030] The attenuating sheet is arranged on the light path of the measuring laser between the laser and the vacuum cavity, for attenuating the energy of the measuring laser, so as to prevent the measuring laser from damaging the middle infrared detector to be measured.

[0031] Further, the cavity of the vacuum cavity is made of stainless steel material, and the light window on the side wall of the cavity is made of white gem material.

[0032] Further, the laser adopts a 3.8 mu m quantum cascade laser, and the output is a Gaussian light spot with a spot diameter of 2.5-3.5 mm.

[0033] Further, the attenuating sheet adopts a middle infrared neutral density attenuating sheet with a transmittance of 10%;

[0034] The acquisition card is an NI data acquisition card.

[0035] The laser power meter is an ophir laser power meter with a sensitive pyroelectric probe, and the range is 3 W.

[0036] The spot analyzer adopts a DataRay spot analyzer, and the measurable wave band is 2 mu m-16 mu m.

[0037] The current amplifier adopts a Stanford SR570 current amplifier.

[0038] The electric resistance measuring unit adopts a universal meter.

[0039] Further, the temperature detector adopts a thermistor.

[0040] A method for measuring the responsivity of a mid-infrared detector, using the above-mentioned device for measuring the responsivity of a mid-infrared detector, is characterized in that it comprises the following steps:

[0041] Step 1: Place the mid-infrared detector to be tested into a vacuum chamber, aligning its photosensitive surface with the optical window on the vacuum chamber. Lead the output signal line of the mid-infrared detector to be tested from the vacuum chamber and connect it to the current amplifier, acquisition card, and processing unit in sequence. Set the temperature of the vacuum chamber to a preset temperature through the temperature control unit.

[0042] Step 2: Turn on the laser and emit a measuring laser. The measuring laser passes through the optical window on the vacuum chamber and reaches the photosensitive surface of the mid-infrared detector to be tested. The mid-infrared detector to be tested converts the received measuring laser into a current signal and sends it to the current amplifier. The current amplifier converts the received current signal into a voltage signal U.

[0043] Step 3: Collect the voltage signal U through the acquisition card and send it to the processing unit;

[0044] Step 4: Measure the spot shape of the measuring laser emitted by the laser using a spot analyzer;

[0045] Step 5: The processing unit obtains the light spot shape and calculates the ratio k of the light spot power in the central area to the total light spot power; the size of the central area is consistent with the size of the detector photosensitive surface of the mid-infrared detector to be tested;

[0046] Step 6: Use a laser power meter to measure the total laser power P emitted by the laser and send it to the processing unit;

[0047] Step 7: The processing unit calculates the response rate R' of the incident light to the mid-infrared detector to be tested:

[0048]

[0049] Where G is the amplification factor of the current amplifier, and T is the transmittance of the optical window on the vacuum cavity to the measurement laser;

[0050] Step 8: Gradually increase the power of the measuring laser emitted by the laser until the voltage signal U collected by the acquisition card does not increase linearly with the measuring laser power. Repeat steps 3 to 7 each time the power is increased to obtain multiple response rates R'. The average of the multiple response rates R' is the response rate R of the mid-infrared detector to be measured.

[0051] Beneficial effects of the present invention:

[0052] 1. The application provides a response rate measuring device and method for a mid-infrared detector, which solves the problem of inaccurate measurement of actual received laser power density of the mid-infrared detector when the detector photosensitive surface of the mid-infrared detector is smaller than the spot size of the measuring laser, the total power of the measuring laser can be measured by using a laser power meter, the ratio of the central area spot power to the total spot power of the incident photosensitive surface of the detector can be measured by using a spot analyzer, and then the power density value of the incident photosensitive surface of the detector can be accurately measured and calculated, thereby improving the measurement accuracy of the response rate of the mid-infrared detector.

[0053] 2. The application sets the mid-infrared detector in a vacuum cavity, and sets a temperature control unit for the vacuum cavity, the temperature control unit can ensure that the temperature of the vacuum cavity is in a stable state, thereby eliminating the influence of temperature on the response rate of the mid-infrared detector and improving the measurement accuracy of the response rate of the mid-infrared detector. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is a structural schematic diagram of a to-be-measured mid-infrared detector;

[0055] REFERENCE NUMERALS

[0056] 11-Pt thin film resistor, 12-detector photosensitive surface, 13-detector electrode, 14-Pt resistor electrode, 15-common electrode;

[0057] Figure 2 is a structural schematic diagram of an embodiment of a response rate measuring device for a mid-infrared detector of the application (not including a laser power meter and a spot analyzer);

[0058] Figure 3 is a structural schematic diagram of step 4 in the embodiment of the application for measuring the spot shape by using a spot analyzer;

[0059] Figure 4 is a structural schematic diagram of step 6 in the embodiment of the application for measuring the total power of the laser by using a laser power meter;

[0060] Figure 5 is a relationship curve diagram between the measured response rate R' and the voltage signal U in the embodiment of the application;

[0061] REFERENCE NUMERALS

[0062] 1-laser, 2-attenuation sheet, 3-vacuum cavity, 4-to-be-measured mid-infrared detector, 5-heating / cooling machine, 6-temperature controller, 7-current amplifier, 8-acquisition card, 9-processing unit, 10-multimeter, 16-laser power meter, 17-spot analyzer. DETAILED DESCRIPTION

[0063] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings and embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0064] First, if Figure 1 As shown, the mid-infrared detector includes a Pt thin-film resistor 11, a detector photosensitive surface 12, a detector electrode 13, a Pt resistor electrode 14, and a common electrode 15. One end of the Pt thin-film resistor 11 is connected to the Pt resistor electrode 14, and the other end is connected to the common electrode 15. The Pt thin-film resistor 11 adopts a thin-film platinum filament structure with a line width of 15μm. The common electrode 15 and the detector electrode 13 are both in contact with the detector photosensitive surface 12. The common electrode 15 and the detector electrode 13 constitute the output end of the mid-infrared detector. In this embodiment, the mid-infrared detector 4 to be tested uses a photovoltaic mercury cadmium telluride detector with a detector photosensitive surface 12 measuring 0.1×0.1mm. The converted current signal is extracted through the detector electrode 13 and the common electrode 14. The Pt thin-film resistor 11 is simultaneously etched on the detector to monitor the detector temperature in real time, and the resistance value signal is extracted through the Pt resistor electrode 14 and the common electrode 15.

[0065] The embodiment of the present invention provides a device for measuring the responsivity of a mid-infrared detector, such as Figure 2 As shown, it includes a laser 1, an attenuation plate 2, a vacuum chamber 3, a temperature control unit, a current amplifier 7, an acquisition card 8, a multimeter 10, a laser power meter 16, a spot analyzer 17 and a processing unit 9;

[0066] The laser 1 is used to emit a measuring laser to the mid-infrared detector 4 to be measured; the laser 1 adopts a 3.8 μm quantum cascade laser, and the output is a Gaussian spot with a spot diameter of about 3 mm.

[0067] The side wall of the vacuum chamber 3 is provided with an optical window corresponding to the measuring laser. The interior of the vacuum chamber 3 is used to set the mid-infrared detector 4 to be measured, and the detector photosensitive surface 12 is made to correspond to the optical window. The cavity of the vacuum chamber 3 is made of stainless steel with an inner diameter of 200mm. The vacuum degree can be maintained at 10 -4 Pa; the light window on the side wall of the vacuum chamber 3 is made of white sapphire material with high transmittance in the mid-infrared band.

[0068] The attenuation plate 2 is disposed on the optical path of the measurement laser between the laser 1 and the vacuum chamber 3 to attenuate the energy of the measurement laser to prevent the measurement laser from damaging the mid-infrared detector 4 to be measured. In this embodiment, the attenuation plate 2 is a mid-infrared neutral density attenuation plate with a transmittance of 10%.

[0069] The working end of the temperature control unit is connected with the vacuum cavity 3, and is used for controlling the temperature in the vacuum cavity 3.

[0070] The input end of the current amplifier 7 is used for being connected with the output end of the to-be-tested mid-infrared detector 4, so as to convert the current signal output by the to-be-tested mid-infrared detector 4 into a voltage signal and amplify the voltage signal; the current amplifier 7 adopts a Stanford SR570 current amplifier, and the amplification range is 100 μA|V (that is, 100 μA current is converted into 1 V voltage, G=10 4 ), and the amplified voltage is collected by the NI data acquisition card and then displayed by the computer.

[0071] The input end of the acquisition card 8 is connected with the output end of the current amplifier 7, and is used for collecting the voltage signal output by the current amplifier 7; the acquisition card 8 is an NI data acquisition card.

[0072] The laser power meter 16 is used for measuring the laser power of the measurement laser; the laser power meter 16 is an ophir laser power meter, and is provided with a sensitive pyroelectric probe and has a measuring range of 3 W.

[0073] The spot analyzer 17 is used for measuring the spot shape of the measurement laser; the spot analyzer 17 adopts a DataRay spot analyzer, and can measure a wave band of 2 μm to 16 μm.

[0074] The measuring end of the multimeter 10 is connected with the Pt resistance electrode 14 and the common electrode 15, the output end of the multimeter 10 is connected with the processing unit 9, and the multimeter 10 is used for monitoring the resistance value of the Pt thin film resistance 11 in real time and sending the resistance value to the processing unit 9.

[0075] The temperature control unit includes the temperature controller 6, the heating / cooling machine 7 and the temperature measuring instrument 18; the control end of the temperature controller 6 is connected with the input end of the heating / cooling machine 7, and is used for controlling the heating / cooling machine 7 to heat or cool; the heating / cooling end of the heating / cooling machine 7 is connected with the vacuum cavity 3, and is used for heating or cooling the vacuum cavity 3; the temperature measuring instrument 18 is arranged in the vacuum cavity 3, and the output end of the temperature measuring instrument 18 is connected with the input end of the temperature controller 6, and is used for feeding back the temperature in the vacuum cavity 3 to the temperature controller 6 in real time; in the embodiment, the temperature measuring instrument 18 adopts a thermistor.

[0076] The processing unit 9 is connected with the output end of the acquisition card 8 and the output end of the multimeter 10, and is used for calculating the response rate of the to-be-tested mid-infrared detector 4 according to the current signal, the laser power and the spot shape; in the embodiment, the processing unit 9 adopts a computer.

[0077] The measuring laser emitted by the laser 1 is attenuated by the attenuation plate 2, and is incident on the mid-infrared detector 4 to be measured through the white sapphire window of the vacuum chamber 3. The mid-infrared detector 4 to be measured converts the optical signal into a current signal and inputs it into the current amplifier 7. The current amplifier 7 converts the current signal into a voltage signal. The output voltage signal is collected by the NI data acquisition card. The real-time resistance of the Pt thin film resistor 11 is measured by the multimeter 10, and the response voltage value and the Pt resistance value are both displayed by the computer. The laser power density of the laser 1 incident on the detector photosensitive surface 12 is measured by the laser power meter 16 and the spot analyzer 17.

[0078] The above-mentioned measuring device is used to measure the responsivity of the mid-infrared detector 4 to be measured:

[0079] Step 1. Place the mid-infrared detector 4 to be tested into the vacuum chamber 3, and make the detector photosensitive surface 12 correspond to the light window on the vacuum chamber 3. Lead the output signal line of the mid-infrared detector 4 to be tested from the vacuum chamber 3, and connect the current amplifier 7, the acquisition card 8 and the processing unit in sequence. Close the vacuum chamber 3 and evacuate the vacuum chamber. Set the temperature of the vacuum chamber 3 to 10°C through the temperature control unit. Use a multimeter 10 to measure the resistance value of the Pt thin film resistor 11. When the resistance remains unchanged at 207.58Ω, it indicates that the mid-infrared detector to be tested has reached a thermal equilibrium state and the temperature is stable at 10°C.

[0080] Step 2: Turn on the laser 1. The laser 1 emits a measuring laser. The measuring laser passes through the optical window on the vacuum chamber 3 and reaches the detector photosensitive surface 12 of the mid-infrared detector 4 to be measured. The mid-infrared detector 4 to be measured converts the received measuring laser into a current signal and sends it to the current amplifier 7. The current amplifier 7 converts the received current signal into a voltage signal U=53.5mW.

[0081] Step 3: The voltage signal U is collected by the acquisition card 8 and sent to the processing unit.

[0082] Step 4: Figure 2 As shown, the spot shape of the measuring laser light emitted by the laser 1 is measured by the spot analyzer 17 .

[0083] Step 5: The processing unit obtains the light spot shape and calculates the ratio k=0.0121 of the light spot power in the central area S=0.1mm×0.1mm to the total light spot power; the size of the central area is consistent with the size of the detector photosensitive surface 12 of the mid-infrared detector 4 to be tested.

[0084] Step 6: Figure 4 As shown, a laser power meter 16 is used to measure the total laser power P = 6.24 mW emitted by the laser 1 after the laser passes through the attenuation plate 2 with a transmittance of 10%, and sends it to the processing unit.

[0085] At this time, the power incident to the photosensitive surface 12 of the detector is calculated by the following formula:

[0086] P' = 0.9kP = 0.068mW

[0087] wherein 0.9 is the transmittance of the sapphire material light window at a wavelength of 3.8 μm;

[0088] Step 7, the processing unit calculates the responsivity R' incident to the to-be-tested mid-infrared detector 4:

[0089]

[0090] wherein G is the amplification of the current amplifier 7, and T = 0.9.

[0091] Step 8, gradually increase the power of the measurement laser emitted by the laser 1 until the voltage signal U collected by the acquisition card 8 does not linearly increase with the measurement laser power; each time the power is increased, steps 3-7 are repeated, as shown in the following table: Figure 5 Thus, the responsivity 0.79 A / W, 0.79 A / W, 0.79 A / W... is obtained, and the average of the responsivity 0.79 A / W, 0.79 A / W, 0.79 A / W... is the responsivity R = 0.79 A / W of the mercury cadmium telluride mid-infrared detector.

[0092] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A responsivity measuring device for a mid-infrared detector, the mid-infrared detector comprising a Pt thin film resistor (11), a detector photosensitive surface (12), a detector electrode (13), a Pt resistor electrode (14), and a common electrode (15); one end of the Pt thin film resistor (11) is connected to the Pt resistor electrode (14), and the other end is connected to the common electrode (15); the common electrode (15) and the detector electrode (13) are both in contact with the detector photosensitive surface (12); the common electrode (15) and the detector electrode (13) constitute an output end of the mid-infrared detector; Its characteristics are: It comprises a laser (1), a vacuum chamber (3), a current amplifier (7), an acquisition card (8), a laser power meter (16), a spot analyzer (17) and a processing unit (9); The laser (1) is used to emit a measuring laser to a mid-infrared detector (4) to be measured; A light window corresponding to the measuring laser is provided on a side wall of the vacuum chamber (3); a mid-infrared detector (4) to be measured is arranged inside the vacuum chamber (3), and the detector photosensitive surface (12) is made to correspond to the light window; The input end of the current amplifier (7) is used to be connected to the output end of the mid-infrared detector (4) to be tested, so as to convert the current signal output by the mid-infrared detector (4) to be tested into a voltage signal and amplify the voltage signal; The input end of the acquisition card (8) is connected to the output end of the current amplifier (7) and is used to acquire the voltage signal output by the current amplifier (7); The laser power meter (16) is used to measure the laser power of the measuring laser; The light spot analyzer (17) is used to measure the light spot shape of the measuring laser; The processing unit (9) is connected to the output end of the acquisition card (8) and is used to calculate the response rate of the mid-infrared detector (4) to be tested based on the current signal, laser power and light spot shape.

2. The responsivity measurement device for a mid-infrared detector according to claim 1, characterized in that: It also includes a temperature control unit; The active end of the temperature control unit is connected to the vacuum chamber (3) and is used to control the temperature in the vacuum chamber (3).

3. The responsivity measurement device for a mid-infrared detector according to claim 2, characterized in that: The temperature control unit includes a temperature controller (6), a heating / refrigeration machine (7) and a temperature measuring instrument (18); The control end of the temperature controller (6) is connected to the input end of the heating / refrigeration machine (7) to control the heating / refrigeration machine (7) to heat or cool; The heating / cooling end of the heating / cooling machine (7) is connected to the vacuum chamber (3) and is used to heat or cool the vacuum chamber (3); The temperature measuring instrument (18) is arranged in the vacuum chamber (3), and its output end is connected to the input end of the temperature controller (6) for feeding back the temperature in the vacuum chamber (3) to the temperature controller (6) in real time.

4. The responsivity measurement device for a mid-infrared detector according to claim 1, 2 or 3, characterized in that: Also included is a resistance measuring unit; The measuring end of the resistance measuring unit is connected to the Pt resistance electrode (14) and the common electrode (15), and the output end is connected to the processing unit (9) for real-time monitoring of the resistance value of the Pt thin film resistor (11) and sending the result to the processing unit (9).

5. The responsivity measurement device for a mid-infrared detector according to claim 4, characterized in that: Also includes a damping plate (2); The attenuation plate (2) is arranged on the optical path of the measuring laser between the laser (1) and the vacuum chamber (3) and is used to attenuate the energy of the measuring laser to prevent the measuring laser from damaging the mid-infrared detector (4) to be measured.

6. The responsivity measurement device for a mid-infrared detector according to claim 5, characterized in that: The body of the vacuum chamber (3) is made of stainless steel, and the light windows on the side walls are made of white sapphire.

7. The responsivity measurement device for a mid-infrared detector according to claim 6, characterized in that: The laser (1) adopts a 3.8 μm quantum cascade laser, and the output is a Gaussian spot with a spot diameter of 2.5 to 3.5 mm.

8. The responsivity measurement device for a mid-infrared detector according to claim 7, characterized in that: The attenuation sheet (2) is a mid-infrared neutral density attenuation sheet with a transmittance of 10%; The acquisition card (8) is a NI data acquisition card; The laser power meter (16) is an Ophir laser power meter with a sensitive pyroelectric probe and a measuring range of 3W; The light spot analyzer (17) adopts a DataRay light spot analyzer, which can measure the wavelength range from 2 μm to 16 μm; The current amplifier (7) adopts Stanford SR570 current amplifier; The resistance measuring unit adopts a multimeter (10).

9. The responsivity measurement device for a mid-infrared detector according to claim 3, characterized in that: The temperature measuring instrument (18) adopts a thermistor.

10. A method for measuring the responsivity of a mid-infrared detector, using the responsivity measuring device for a mid-infrared detector according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Place the mid-infrared detector (4) to be tested into the vacuum chamber (3), and make the detector's photosensitive surface (12) correspond to the light window on the vacuum chamber (3); lead the output end signal line of the mid-infrared detector (4) to be tested from the vacuum chamber (3), and connect it to the current amplifier (7), the acquisition card (8) and the processing unit in sequence; and set the temperature of the vacuum chamber (3) to a preset temperature through the temperature control unit; Step 2: Turn on the laser (1), the laser (1) emits a measuring laser, and the measuring laser passes through the optical window on the vacuum chamber (3) to reach the detector photosensitive surface (12) of the mid-infrared detector (4) to be measured; the mid-infrared detector (4) to be measured converts the received measuring laser into a current signal and sends it to the current amplifier (7); the current amplifier (7) converts the received current signal into a voltage signal U; Step 3: collecting the voltage signal U through the acquisition card (8) and sending it to the processing unit; Step 4: measuring the spot shape of the measuring laser light emitted by the laser (1) by using a spot analyzer (17); Step 5: The processing unit obtains the light spot shape and calculates the ratio k of the light spot power in the central area to the total light spot power; the size of the central area is consistent with the size of the detector photosensitive surface (12) of the mid-infrared detector (4) to be tested; Step 6: Using a laser power meter (16), measure the total laser power P of the measurement laser emitted by the laser (1), and send the result to the processing unit; Step 7: The processing unit calculates the response rate R' of the incident light to the mid-infrared detector (4) to be tested: Wherein, G is the amplification factor of the current amplifier (7), and T is the transmittance of the optical window on the vacuum chamber (3) to the measuring laser; Step 8: gradually increase the power of the measuring laser emitted by the laser (1) until the voltage signal U collected by the acquisition card (8) does not increase linearly with the measuring laser power; each time the power is increased, repeat steps 3 to 7 to obtain multiple response rates R', and obtain the average value of the multiple response rates R', which is the response rate R of the mid-infrared detector (4) to be measured.

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