Multi-channel intermediate infrared detector wide temperature range responsivity calibration device and method

Abstract

The invention discloses a multichannel intermediate infrared detector wide temperature range responsivity calibration device and method, and solves the problems that the responsivity changes along with the temperature in the existing intermediate infrared detector responsivity calibration, the responsivity consistency of different intermediate infrared detectors is poor, and the calibration efficiency of a large batch of intermediate infrared detectors is not high. According to the invention, the plurality of intermediate infrared detectors to be calibrated are arranged in the vacuum cavity, and the temperature control unit is arranged in the vacuum cavity, so that the temperature of the intermediate infrared detectors to be calibrated can be accurately controlled in a stable range, the problems that the temperature of the intermediate infrared detectors is sensitive and the response rate drifts along with the temperature are solved, and the accuracy of response rate calibration is ensured.

Description

Technical Field

[0001] The invention relates to a mid-infrared detector response rate calibration device and method, and in particular to a multi-channel mid-infrared detector wide temperature range response rate calibration device and method. Background Art

[0002] At present, infrared laser detection technology is developing rapidly. In laser parameter measurement, the development of optoelectronic array systems for measuring parameters such as mid-infrared laser power / energy density distribution usually requires hundreds of mid-infrared detectors. Compared with near-infrared detectors with better consistency, the response rate of mid-infrared detectors varies greatly from person to person and changes with the temperature of the working environment. Accurately measuring the change pattern of the response rate of each mid-infrared detector with temperature is a key link in equipment development.

[0003] Spectral responsivity is one of the basic parameters that reflect the response of the detector, which refers to the response caused by the unit incident light radiation power. At present, the calibration of the absolute spectral responsivity of the detector mainly uses lasers as the light source. In order to improve the measurement accuracy, the power density is often traced back to the cryogenic radiometer. The cryogenic radiometer is currently an internationally recognized optical power measurement benchmark. It uses the principle of electrical substitution measurement under low-temperature superconductivity to trace the optical radiation measurement to the measurement of electrical parameters that can be accurately measured, thereby achieving accurate measurement of the absolute power value of the optical radiation. However, cryogenic radiometers are expensive, the system is complex, and the operation is difficult. It is difficult to accurately measure the responsivity of large quantities of mid-infrared detectors in a short period of time.

[0004] The Chinese patent with publication number CN 102305663A discloses "A calibration device for mid-infrared detector response rate changes with temperature", which controls the detector temperature through a high and low temperature control box and uses a black body + filter method to test the detector response rate. Compared with the laser + cryogenic radiometer method, the device has a simple structure, is easy to operate, and greatly reduces the experimental cost; however, it can only measure a single detector and still cannot meet the task requirements of mass mid-infrared detector response rate calibration.

[0005] The Chinese patent "A method and system for testing room temperature response parameters of infrared detectors" with publication number CN 116295870A uses a black body + laser two light sources to irradiate simultaneously, and can simultaneously calculate the response rate, linear dynamic range and saturation threshold of the detector under test. However, this method can only measure the relative spectral response rate of the detector, and the measurement accuracy of the absolute spectral response rate is not high. In addition, it can only measure the response parameters at room temperature, and the working environment temperature is limited. Summary of the invention

[0006] In order to solve the technical problems in the existing mid-infrared detector responsivity calibration, such as the response rate varies with temperature, the response rates of different mid-infrared detectors have poor consistency, the calibration efficiency of large batches of mid-infrared detectors is low, and the measurement temperature range is limited, the present invention provides a multi-channel mid-infrared detector wide temperature range responsivity calibration device and method.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A multi-channel mid-infrared detector wide temperature range response rate calibration device, which is special in that it includes: a vacuum chamber with a light window on the side wall, a detector mounting assembly arranged in the vacuum chamber, a light radiation unit arranged outside the vacuum chamber and corresponding to the light window, a multi-way switch test meter arranged outside the vacuum chamber and whose signal receiving end is connected to the detector mounting assembly, a preamplifier connected to the output end of the multi-way switch test meter, a temperature control unit connected to the detector mounting assembly, and an industrial computer connected to the light radiation unit, the multi-way switch test meter, the temperature control unit and the preamplifier respectively;

[0009] The light radiation unit is used to emit calibration light to the light window, so that the calibration light passes through the light window and is incident on one of the multiple mid-infrared detectors to be calibrated.

[0010] The detector installation assembly is used to install multiple mid-infrared detectors to be calibrated, so that the photosensitive surfaces of the mid-infrared detectors to be calibrated correspond to the light window with a gap, and the multiple mid-infrared detectors to be calibrated are electrically connected to the multi-way switch test meter through the detector installation assembly;

[0011] The multi-way switch test table is used to perform switching on the electrical signals output by the multiple mid-infrared detectors to be calibrated and send them to the preamplifier;

[0012] The preamplifier is used to amplify the received electrical signal;

[0013] The temperature control unit is used to control the temperature of the mid-infrared detector to be calibrated through the detector mounting assembly;

[0014] The industrial computer is used to control the light radiation unit, the temperature control unit and the multi-way switch test table, and is also used to perform data processing.

[0015] Further, the light radiation unit includes a light radiation source and a displacement stage;

[0016] The optical radiation source is arranged on the active end of the displacement stage, and the active end of the optical radiation source corresponds to the optical window;

[0017] The displacement platform is connected to the industrial computer and is used for displacement under the control of the industrial computer, so that the optical radiation source can respectively emit calibration light to each mid-infrared detector to be calibrated.

[0018] Further, a chopper and a lock-in amplifier are included;

[0019] The chopper is arranged on the optical path between the light radiation unit and the vacuum chamber and connected to the first input terminal of the phase-locked amplifier, and is used to modulate the calibration light emitted by the light radiation unit and send its modulation frequency to the phase-locked amplifier;

[0020] The second input end of the phase-locked amplifier is connected to the output end of the preamplifier, and the output end is connected to the input end of the industrial computer, and is used to process the electrical signal output by the preamplifier through frequency modulation and then send it to the industrial computer.

[0021] Further, the detector mounting assembly comprises a pressing plate, a cold head, a mounting plate, a connecting plate and a circuit board which are sequentially arranged in parallel and connected to each other;

[0022] The pressure plate and the cold head are used to arrange a plurality of mid-infrared detectors to be calibrated in an array; the pins of each mid-infrared detector to be calibrated pass through the cold head, the mounting plate, and the connecting plate in sequence and are then inserted into the pin slots of the circuit board;

[0023] The output signal line of the circuit board passes through the side wall of the vacuum chamber and is connected to the signal receiving end of the multi-way switch test meter.

[0024] Furthermore, it also includes a filter;

[0025] The filter is arranged on the optical path between the light radiation unit and the chopper, and is used to control the response wavelength of the calibrated response rate.

[0026] Furthermore, a cold head sleeve is provided on the inner wall of the vacuum chamber;

[0027] The cold head is detachably connected to the cold head sleeve;

[0028] A mechanical pump and a molecular pump are also connected outside the vacuum chamber;

[0029] The mechanical pump and the molecular pump are used to evacuate the vacuum chamber.

[0030] Further, the temperature control unit includes a temperature controller, a heating / refrigerating machine and a temperature sensor;

[0031] The first input end of the temperature controller is connected to the industrial computer, and the output end thereof is connected to the input end of the heating / refrigerating machine, so as to control the heating / refrigerating machine to heat or cool;

[0032] The active end of the heating / cooling machine is connected to the cold head sleeve, and is used to heat or cool each mid-infrared detector to be calibrated through the cold head sleeve and the cold head;

[0033] The temperature sensor is installed on the cold head sleeve or the cold head and is connected to the temperature controller to feed back the current temperature to the temperature controller.

[0034] Furthermore, the optical radiation source is a black body radiation source, and the aperture of the light exit hole is 8 mm;

[0035] The filter is a 1-inch infrared bandpass filter with a transmission wavelength range of 3.5 μm to 4.1 μm, a central wavelength of 3.75 μm, a half-peak full width of 500 nm, a diameter of 25.4 mm, and a thickness of 0.84 mm;

[0036] The light window is made of white sapphire material;

[0037] The cold head is made of copper plate.

[0038] A method for calibrating the response rate of a multi-channel mid-infrared detector over a wide temperature range adopts the above-mentioned device for calibrating the response rate of a multi-channel mid-infrared detector over a wide temperature range, and the method is special in that it comprises the following steps:

[0039] Step 1: install multiple mid-infrared detectors to be calibrated on the detector mounting assembly, place it in the vacuum chamber, connect the output end of the detector mounting assembly to the signal receiving end of the multi-way switch test meter, and close the vacuum chamber;

[0040] Step 2: The industrial computer starts the temperature control unit, and the temperature control unit controls the temperature of the mid-infrared detector to be calibrated at a first temperature point;

[0041] Step 3: The industrial computer controls the light radiation unit to emit calibration light to the light window on the vacuum chamber, so that the calibration light passes through the light window and is incident on one of the designated mid-infrared detectors to be calibrated;

[0042] Step 4: The industrial computer controls the multi-way switch test table to select the designated mid-infrared detector to be calibrated, and the electrical signal U' output by the designated mid-infrared detector to be calibrated is received and amplified by the preamplifier, and the obtained electrical signal U is sent to the industrial computer;

[0043] Step 5: The industrial computer calculates the response rate R of the designated mid-infrared detector to be calibrated at the first temperature point through the electrical signal U:

[0044]

[0045] Wherein, A' is the photosensitive surface area of ​​the mid-infrared detector to be calibrated, S is the calibration light power density emitted by the light radiation unit, and r is the amplification factor of the preamplifier;

[0046] Step 6: Repeat steps 3 to 5 for each other mid-infrared detector to be calibrated, and obtain the response rate of each mid-infrared detector to be calibrated at the first temperature point;

[0047] Step 7: The temperature control unit controls the temperature of the mid-infrared detector to be calibrated at other temperature points, and repeats steps 3 to 6 at each temperature point to obtain the response rate of each mid-infrared detector to be calibrated at each temperature, thereby completing the calibration of each mid-infrared detector to be calibrated.

[0048] Furthermore, step 5 specifically includes:

[0049] 5.1. The industrial computer obtains the transmission wavelength range λ1~λ2 of the filter, the calibration light wavelength λ incident on the designated mid-infrared detector to be calibrated, and the transmittance T of the filter at wavelength λ. λ , the temperature T of the light radiation source, the transmittance t of the light window, the aperture area A at the light exit hole of the light radiation source, the root mean square conversion coefficient C of the radiation energy of the light radiation source rms , the effective emissivity ε of the optical radiation source, the distance L from the aperture to the photosensitive surface of the designated mid-infrared detector 14 to be calibrated, the photosensitive surface area A' of the designated mid-infrared detector to be calibrated, and the amplification factor r of the preamplifier;

[0050] 5.2. Calculation of the radiance of the light radiation source by industrial computer

[0051]

[0052] Wherein, c1 is the first radiation constant, c2 is the second radiation constant, and e is a constant;

[0053] 5.3. The industrial computer calculates the calibration light power density S emitted by the optical radiation source to the designated mid-infrared detector to be calibrated:

[0054]

[0055] 5.4. The industrial computer calculates the response rate R of the designated mid-infrared detector to be calibrated at the first temperature point through the electrical signal U:

[0056]

[0057] Beneficial effects of the present invention:

[0058] 1. The present invention provides a multi-channel mid-infrared detector wide temperature range response rate calibration device and method, which arranges multiple mid-infrared detector arrays to be calibrated on a detector mounting assembly, and switches them through a multi-way switch test table. It can not only calibrate in batches at one time, but also the individual differences in the response rates of multiple mid-infrared detectors are not affected by each other, which greatly improves the calibration efficiency and realizes the automatic calibration of the response rates of multiple mid-infrared detectors.

[0059] 2. The present invention provides a multi-channel mid-infrared detector wide temperature range response rate calibration device and method, which sets multiple mid-infrared detectors to be calibrated in a vacuum chamber, and provides a temperature control unit for the vacuum chamber, which can accurately control the temperature of the mid-infrared detectors to be calibrated within a stable range, solves the problem that the mid-infrared detectors are temperature sensitive and the response rate drifts with temperature, and ensures the accuracy of the response rate calibration.

[0060] 3. The present invention solves the problem that in the traditional mid-infrared detector response rate calibration method, when the mid-infrared detector is in a low-temperature environment, the detector window and the temperature control box window are prone to frost; by setting a vacuum chamber and pumping out the air, the mid-infrared detector to be calibrated is in a vacuum environment, and the cavity does not contain oxygen, water vapor and other components. At the same time, the white sapphire material window on the vacuum chamber cannot transfer heat with the mid-infrared detector to be calibrated and the cold head, thereby avoiding frosting on the detector window and the vacuum chamber window. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a structural schematic diagram of an embodiment of a multi-channel mid-infrared detector wide temperature range response rate calibration device of the present invention;

[0062] Figure 2 is a schematic diagram of the structure of a detector installation assembly and a plurality of mid-infrared detectors to be calibrated in an embodiment of the present invention;

[0063] Figure 3 It is a response rate calibration result curve graph drawn for one of the mid-infrared detectors after calibrating each mid-infrared detector using a multi-channel mid-infrared detector wide temperature range response rate calibration device and method provided by the present invention in an embodiment of the present invention.

[0064] Figure Number:

[0065] 1-blackbody radiation source, 2-filter, 3-chopper, 4-vacuum chamber, 5-mechanical pump and molecular pump, 6-cold head sleeve, 7-multi-way switch test table, 8-preamplifier, 9-lock-in amplifier, 10-industrial computer, 11-temperature controller, 12-heating / refrigeration machine, 13-detector installation assembly, 14-mid-infrared detector to be calibrated, 15-pressing plate, 16-cold head, 17-mounting plate, 18-connecting plate, 19-circuit board. DETAILED DESCRIPTION

[0066] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] The embodiment of the present invention provides a multi-channel mid-infrared detector wide temperature range response rate calibration device, such as Figure 1 As shown, it includes a vacuum chamber 4 with a light window on the side wall, a detector installation assembly 13 arranged in the vacuum chamber 4, a light radiation unit arranged outside the vacuum chamber 4 and corresponding to the light window, a filter 2 arranged outside the vacuum chamber 4 and located on the light path between the light radiation unit and the vacuum chamber 4, a chopper 3 arranged outside the vacuum chamber 4 and located on the light path between the filter 2 and the vacuum chamber 4, a multi-way switch test meter 7 arranged outside the vacuum chamber 4 and whose signal receiving end is connected to the detector installation assembly 13, a preamplifier 8 connected to the output end of the multi-way switch test meter 7, a phase-locked amplifier 9 connected to the output end of the preamplifier 8, a temperature control unit connected to the detector installation assembly 13, and an industrial computer 10 respectively connected to the light radiation unit, the multi-way switch test meter 7, the temperature control unit and the phase-locked amplifier 9.

[0068] The light radiation unit is used to emit calibration light to the light window, so that the calibration light can be incident on any one of the 25 mid-infrared detectors 14 to be calibrated through the light window; specifically, the light radiation unit includes a light radiation source 1 and a displacement stage; the light radiation source 1 is arranged on the active end of the displacement stage, and the active end of the light radiation source 1 corresponds to the light window; the displacement stage is connected to the industrial computer 10, and is used to move under the control of the industrial computer 10, so that the light radiation source 1 can respectively emit calibration light to each mid-infrared detector 14 to be calibrated. In this embodiment, the light radiation source 1 is a black body radiation source, and its light exit aperture is 8 mm; the black body radiation source can provide stable calibration light; the displacement stage is a two-dimensional displacement stage, and the black body radiation source can be moved by controlling the displacement stage.

[0069] The filter 2 is arranged on the optical path between the light radiation unit and the chopper 3, and is used to control the response wavelength of the calibration response rate. In this embodiment, the filter 2 is a 1-inch infrared bandpass filter with a central wavelength of 3.75 μm, a half-peak full width of 500 nm, a diameter of 25.4 mm, and a thickness of 0.84 mm.

[0070] The chopper 3 is connected to the first input terminal of the phase-locked amplifier 9 and is used for modulating the calibration light emitted by the light radiation unit and sending its modulation frequency to the phase-locked amplifier 9 .

[0071] The detector installation assembly 13 is used to install 25 mid-infrared detectors 14 to be calibrated, so that the photosensitive surface of the mid-infrared detector 14 to be calibrated corresponds to the light window with a gap, and the 25 mid-infrared detectors 14 to be calibrated are electrically connected to the multi-way switch test table 7 through the detector installation assembly 13; specifically, as Figure 2As shown, the detector installation assembly 13 includes a pressing plate 15, a cold head 16, a mounting plate 17, a connecting plate 18 and a circuit board 19 which are arranged in parallel and connected to each other by screws or bolts; the cold head 16 is provided with grooves arranged in an array, and the tube shells of each mid-infrared detector 14 to be calibrated can be respectively embedded in each groove, and the pins of each mid-infrared detector 14 to be calibrated pass through the cold head 16, the mounting plate 17, and the connecting plate 18 in sequence and finally insert into the pin slot of the circuit board 19; the pressing plate 15 is pressed on the outside of each mid-infrared detector 14 to be calibrated, and is detachably connected to the cold head 16 by bolts, so that 25 mid-infrared detectors 14 to be calibrated are arranged in an array between the pressing plate 15 and the cold head 16; the output signal line of the circuit board 19 passes through the side wall of the vacuum chamber 4 and is connected to the signal receiving end of the multi-way switch test meter 7. In this embodiment, the cold head 16 is made of copper plate.

[0072] A cold head sleeve 6 is provided on the inner wall of the vacuum chamber 4; the cold head 16 is detachably connected to the cold head sleeve 6. A mechanical pump and a molecular pump 5, a compressor, etc. are also connected to the vacuum chamber 4 to evacuate the vacuum chamber 4 and maintain a vacuum environment. In this embodiment, the optical window on the vacuum chamber 4 is made of white sapphire material.

[0073] The temperature control unit includes a temperature controller 11, a heating / refrigerating machine 12 and a temperature sensor; the first input end of the temperature controller 11 is connected to the industrial computer 10, and the output end thereof is connected to the input end of the heating / refrigerating machine 12, so as to control the heating / refrigerating machine 12 to heat or cool; the action end of the heating / refrigerating machine 12 is connected to the cold head sleeve 6, so as to heat or cool each mid-infrared detector 14 to be calibrated through the cold head sleeve 6 and the cold head 16. The heating / refrigerating machine 12 adopts a combination of a refrigerator and a heating plate, measures the temperature at a specified position through a temperature sensor, drives the refrigerator or the heating plate through a dedicated driving circuit, and gives a driving signal through PID. After the system is stable, the temperature change does not exceed ±0.5°C; the temperature sensor is installed on the cold head sleeve 6 or the cold head 16, and is connected to the temperature controller 11, so as to feed back the current temperature to the temperature controller 11.

[0074] The multi-way switch test table 7 is used to select and switch the electrical signals output by the 25 mid-infrared detectors 14 to be calibrated and send them to the preamplifier 8; when one of the mid-infrared detectors 14 to be calibrated is calibrated, the other mid-infrared detectors 14 to be calibrated are in an open circuit state to prevent signal crosstalk between the mid-infrared detectors 14 to be calibrated.

[0075] The preamplifier 8 is used to amplify the received electrical signal.

[0076] The second input end of the phase-locked amplifier 9 is connected to the output end of the preamplifier 8, and the output end thereof is connected to the input end of the industrial computer 10, so as to process the electrical signal output by the preamplifier 8 by modulating the frequency and then send it to the industrial computer 10.

[0077] The temperature control unit is used to control the temperature of the mid-infrared detector 14 to be calibrated through the detector mounting assembly 13;

[0078] The industrial computer 10 is used to control the light radiation unit, the temperature control unit and the multi-way switch test meter 7, and is also used to receive the electrical signal sent by the lock-in amplifier 9 and perform data processing.

[0079] The working process of the above response rate calibration device includes the following steps:

[0080] Step 1. Set the temperature of the blackbody radiation source itself to 900K and keep it stable; at the same time, install 25 mid-infrared detectors 14 to be calibrated on the detector mounting assembly 13, place it in the vacuum chamber 4, and connect the output end of the detector mounting assembly 13 to the signal receiving end of the multi-way switch test meter 7, and close the vacuum chamber 4.

[0081] Step 2: The industrial computer 10 starts the temperature control unit, which controls the temperature of the mid-infrared detector 14 to be calibrated at a first temperature point, namely -50°C; after the system is stable, the temperature change does not exceed ±0.5°C.

[0082] In other embodiments, this step may also be:

[0083] The mechanical pump and the molecular pump are started to draw a vacuum, and then the industrial computer 10 starts the temperature control unit, which controls the temperature of the mid-infrared detector 14 to be calibrated at a first temperature point, ie, -50°C.

[0084] Step 3, the industrial computer 10 controls the translation stage to align the light exit hole of the black body radiation source with one of the designated mid-infrared detectors 14 to be calibrated, and the black body radiation source emits calibration light to the light window on the vacuum chamber 4, so that the calibration light passes through the light window and is incident on the designated mid-infrared detector 14 to be calibrated.

[0085] Step 4, the industrial computer 10 controls the multi-way switch test table 7 to select the designated mid-infrared detector 14 to be calibrated, and the electrical signal U' output by the designated mid-infrared detector 14 to be calibrated is received by the preamplifier 8 and amplified and then sent to the phase-locked amplifier 9, which modulates, selects frequency, amplifies and performs related operations to obtain the electrical signal U, and then sends the electrical signal U to the industrial computer 10. The preamplifier 8 uses a Stanford SR570 current amplifier, and the gear is set to 1μA|V (that is, every 1μA current is converted into 1V voltage), that is, the r value is 10 6 V / A;

[0086] Step 5. Since the filter 2 is placed behind the light exit hole of the blackbody radiation source, the radiation amount of the blackbody radiation source received by the designated mid-infrared detector 14 to be calibrated is the power within a wavelength range Δλ. Usually, the transmittance of different wavelengths within the Δλ range is different. Therefore, when applying the Planck blackbody radiation formula to calculate the radiation amount of the detector photosensitive surface, the spectral transmittance curve of the filter 2 should be integrated within the bounded domain λ1~λ2. The radiance of the blackbody radiation source is expressed as:

[0087]

[0088] Where, T λ is the transmittance of filter 2 at wavelength λ, is the radiance of the blackbody radiation source in the λ1-λ2 band, λ1-λ2 is the transmission wavelength range of the filter 2, which is 3.5 μm-4.1 μm in this embodiment, λ is the measurement wavelength (in μm), T is the temperature of the blackbody radiation source (in K), k is the Boltzmann constant, c1 is the first radiation constant, and c2 is the second radiation constant; M' bλ is the radiance at a single wavelength; dλ is the integral symbol; e is a constant;

[0089] In this embodiment, λ1 and λ2 are set to 3.5μm and 4.1μm respectively. According to the test results of infrared spectrometer, the transmittance in this band is 92% to 95%, that is, T λ The value is between 92% and 95%, and varies with the wavelength λ; the temperature of the blackbody radiation source is 900K, that is, the value of T is 900K.

[0090] The power density S radiated by the black body radiation source to the designated mid-infrared detector 14 to be calibrated can be expressed as:

[0091]

[0092] Where t is the transmittance of the sapphire window, C rms is the modulated blackbody radiation energy RMS conversion coefficient, ε is the effective emissivity of the blackbody radiation source, which is usually greater than 0.99. A is the aperture area of ​​the blackbody radiation source, and L is the distance from the aperture of the blackbody radiation source to the designated photosensitive surface of the mid-infrared detector 14 to be calibrated. In this embodiment, L=30 cm.

[0093] The industrial computer 10 calculates the response rate R of the designated mid-infrared detector 14 to be calibrated at the first temperature point through the electrical signal U:

[0094]

[0095] Wherein, A' is the photosensitive surface area of ​​the mid-infrared detector 14 to be calibrated, S is the calibration light power density emitted by the light radiation unit, and r is the amplification factor of the preamplifier 8. In this embodiment, A'=10 -4 cm 2 , we calculated that S = 2.4 × 10 - 4 W / cm 2 .

[0096] The calculated response rate of the designated mid-infrared detector 14 to be calibrated at -50°C is 2.58A / W.

[0097] In this embodiment, the transmittance t of the white sapphire window in the 3.5 μm to 4.1 μm band is 90%, and the modulated blackbody radiation energy root mean square conversion coefficient C rms is 0.3536, the effective emissivity ε of the blackbody radiation source is 1, and the aperture area A of the blackbody radiation source is 0.5 cm 2 , the distance L from the aperture to the detector photosensitive surface is 30cm. Then according to the radiance of the black body radiation source The power density S value of the black body radiation source radiating to the designated mid-infrared detector 14 to be calibrated is calculated to be 2.4×10 -4 W / cm 2 .

[0098] Step 6. The industrial computer 10 moves the translation stage equipped with the blackbody radiation source according to the set "S"-shaped stepping route, so that the blackbody radiation source is aligned with the photosensitive surface of each mid-infrared detector 14 to be calibrated in the vacuum chamber 4 in turn. Each time a mid-infrared detector 14 to be calibrated is aligned, steps 3 to 5 are repeated to obtain the response rate of each mid-infrared detector 14 to be calibrated at the first temperature point.

[0099] Step 7: The temperature control unit controls the temperature of the mid-infrared detector 14 to be calibrated at other temperature points, and repeats steps 3 to 6 at each temperature point to obtain the response rate of each mid-infrared detector 14 to be calibrated at each temperature, and then draws the following graph for each mid-infrared detector 14 to be calibrated: Figure 3 The curve diagram shown completes the calibration of each infrared detector 14 to be calibrated.

[0100] This embodiment solves the problems of low measurement efficiency and complex operation in traditional mid-infrared detector response rate measurement, the mid-infrared detector response rate is greatly affected by temperature, the detector response rate consistency is poor, and the measurement temperature range is limited. It realizes the accurate calibration of the response rate of multi-channel mid-infrared detectors in a wide temperature range. The response rate calibration device provided in this embodiment has the characteristics of simple operation, high degree of automation, and high calibration accuracy. The blackbody radiation source provides a stable incident light signal; the detector mounting assembly is used to fix 25 mid-infrared detectors to be calibrated, draw out the detector signal, and realize the heat transfer of the detector; the temperature control unit is used to control the temperature of the 25 mid-infrared detectors to be calibrated, and can realize a temperature cycle in the range of -50℃ to 50℃.

[0101] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A multi-channel mid-infrared detector wide temperature range response rate calibration device, characterized in that: The invention comprises a vacuum chamber (4) having a light window on the side wall, a detector mounting assembly (13) arranged in the vacuum chamber (4), a light radiation unit arranged outside the vacuum chamber (4) and corresponding to the light window, a multi-way switch test meter (7) arranged outside the vacuum chamber (4) and having a signal receiving end connected to the detector mounting assembly (13), a preamplifier (8) connected to the output end of the multi-way switch test meter (7), a temperature control unit connected to the detector mounting assembly (13), and an industrial computer (10) respectively connected to the light radiation unit, the multi-way switch test meter (7), the temperature control unit and the preamplifier (8); The light radiation unit is used to emit calibration light to the light window, so that the calibration light passes through the light window and is incident on one of the plurality of mid-infrared detectors (14) to be calibrated. The detector mounting assembly (13) is used to mount a plurality of mid-infrared detectors (14) to be calibrated, so that the photosensitive surfaces of the mid-infrared detectors (14) to be calibrated correspond to the light window with a gap therebetween, and the plurality of mid-infrared detectors (14) to be calibrated are electrically connected to a multi-way switch test meter (7) through the detector mounting assembly (13); The multi-way switch test table (7) is used to perform switching on the electrical signals output by the plurality of mid-infrared detectors (14) to be calibrated and send them to the preamplifier (8); The preamplifier (8) is used to amplify the received electrical signal; The temperature control unit is used to control the temperature of the mid-infrared detector (14) to be calibrated through the detector mounting assembly (13); The industrial computer (10) is used to control the light radiation unit, the temperature control unit and the multi-way switch test table (7), and is also used to perform data processing.

2. The multi-channel mid-infrared detector wide temperature range response rate calibration device according to claim 1, characterized in that: The light radiation unit comprises a light radiation source (1) and a displacement stage; The optical radiation source (1) is arranged on the active end of the displacement stage, and the active end of the optical radiation source (1) corresponds to the optical window; The displacement platform is connected to the industrial control computer (10) and is used to perform displacement under the control of the industrial control computer (10), so that the optical radiation source (1) can respectively emit calibration light to each mid-infrared detector (14) to be calibrated.

3. The multi-channel mid-infrared detector wide temperature range response rate calibration device according to claim 1 or 2, characterized in that: It also includes a chopper (3) and a lock-in amplifier (9); The chopper (3) is arranged on the optical path between the light radiation unit and the vacuum chamber (4), and is connected to the first input end of the phase-locked amplifier (9), and is used to modulate the calibration light emitted by the light radiation unit and send its modulation frequency to the phase-locked amplifier (9); The second input end of the phase-locked amplifier (9) is connected to the output end of the preamplifier (8), and the output end is connected to the input end of the industrial computer (10), and is used to process the electrical signal output by the preamplifier (8) by modulating the frequency and then send it to the industrial computer (10).

4. The multi-channel mid-infrared detector wide temperature range response rate calibration device according to claim 3, characterized in that: The detector mounting assembly (13) comprises a pressing plate (15), a cold head (16), a mounting plate (17), a connecting plate (18) and a circuit board (19) which are sequentially arranged in parallel and connected to each other; A plurality of mid-infrared detectors (14) to be calibrated are arranged in an array between the pressing plate (15) and the cold head (16); pins of each mid-infrared detector (14) to be calibrated sequentially pass through the cold head (16), the mounting plate (17), and the connecting plate (18) and are then inserted into the pin slots of the circuit board (19); The output signal line of the circuit board (19) passes through the side wall of the vacuum chamber (4) and is connected to the signal receiving end of the multi-way switch test meter (7).

5. The multi-channel mid-infrared detector wide temperature range response rate calibration device according to claim 4, characterized in that: Also includes a filter (2); The optical filter (2) is arranged on the optical path between the light radiation unit and the chopper (3) and is used to control the response wavelength of the calibrated response rate.

6. The multi-channel mid-infrared detector wide temperature range response rate calibration device according to claim 5, characterized in that: A cold head sleeve (6) is provided on the inner wall of the vacuum chamber (4); The cold head (16) is detachably connected to the cold head sleeve (6); The vacuum chamber (4) is also connected to a mechanical pump and a molecular pump (5); The mechanical pump and the molecular pump (5) are used to evacuate the vacuum chamber (4).

7. The multi-channel mid-infrared detector wide temperature range response rate calibration device according to claim 6, characterized in that: The temperature control unit comprises a temperature controller (11), a heating / refrigerating machine (12) and a temperature sensor; The first input end of the temperature controller (11) is connected to the industrial computer (10), and the output end thereof is connected to the input end of the heating / refrigerating machine (12), so as to control the heating / refrigerating machine (12) to heat or cool; The active end of the heating / cooling machine (12) is connected to the cold head sleeve (6) and is used to heat or cool each mid-infrared detector (14) to be calibrated through the cold head sleeve (6) and the cold head (16); The temperature sensor is mounted on the cold head sleeve (6) or the cold head (16) and connected to the temperature controller (11) to feed back the current temperature to the temperature controller (11).

8. The multi-channel mid-infrared detector wide temperature range response rate calibration device according to claim 7, characterized in that: The optical radiation source (1) is a black body radiation source, and the aperture of the light output hole is 8 mm; The filter (2) is a 1-inch infrared bandpass filter with a transmission wavelength range of 3.5 μm to 4.1 μm, a central wavelength of 3.75 μm, a half-maximum full width of 500 nm, a diameter of 25.4 mm, and a thickness of 0.84 mm; The light window is made of white sapphire material; The cold head (16) is made of copper plate.

9. A method for calibrating the response rate of a multi-channel mid-infrared detector over a wide temperature range, using the device for calibrating the response rate of a multi-channel mid-infrared detector over a wide temperature range as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Install a plurality of mid-infrared detectors (14) to be calibrated on a detector mounting assembly (13), place the assembly in a vacuum chamber (4), connect the output end of the detector mounting assembly (13) to the signal receiving end of a multi-way switch test meter (7), and close the vacuum chamber (4); Step 2, the industrial computer (10) starts the temperature control unit, and the temperature control unit controls the temperature of the mid-infrared detector (14) to be calibrated at a first temperature point; Step 3, the industrial computer (10) controls the light radiation unit to emit calibration light to the light window on the vacuum chamber (4), so that the calibration light passes through the light window and is incident on one of the designated mid-infrared detectors (14) to be calibrated; Step 4, the industrial computer (10) controls the multi-way switch test table (7) to select the designated mid-infrared detector (14) to be calibrated, and the electrical signal U' output by the designated mid-infrared detector (14) to be calibrated is received and amplified by the preamplifier (8), and the obtained electrical signal U is sent to the industrial computer (10); Step 5: The industrial computer (10) calculates the response rate R of the designated mid-infrared detector (14) to be calibrated at the first temperature point through the electrical signal U: Wherein, A' is the photosensitive surface area of ​​the designated mid-infrared detector (14) to be calibrated, S is the calibration light power density emitted by the light radiation unit, and r is the amplification factor of the preamplifier (8); Step 6, repeating steps 3 to 5 for each other mid-infrared detector (14) to be calibrated, to obtain the response rate of each mid-infrared detector (14) to be calibrated at the first temperature point; Step 7: The temperature control unit controls the temperature of the mid-infrared detector (14) to be calibrated at other temperature points, and repeats steps 3 to 6 at each temperature point to obtain the response rate of each mid-infrared detector (14) to be calibrated at each temperature, thereby completing the calibration of each mid-infrared detector (14) to be calibrated.

10. The method for calibrating the response rate of a multi-channel mid-infrared detector over a wide temperature range according to claim 9, characterized in that: Step 5 specifically includes: 5.

1. The industrial computer (10) obtains the transmission wavelength range λ1-λ2 of the filter (2), the wavelength λ of the calibration light incident on the designated mid-infrared detector (14) to be calibrated, and the transmittance T of the filter (2) at the wavelength λ. λ , the temperature T of the light radiation source (1), the transmittance t of the light window, the aperture area A at the light exit hole of the light radiation source (1), the root mean square conversion coefficient C of the radiation energy of the light radiation source (1) rms , the effective emissivity ε of the light radiation source (1), the distance L from the aperture to the photosensitive surface of the designated mid-infrared detector 14 to be calibrated, the photosensitive surface area A' of the designated mid-infrared detector (14) to be calibrated, and the amplification factor r of the preamplifier (8); 5.

2. The industrial computer (10) calculates the radiance of the light radiation source (1) Wherein, c1 is the first radiation constant, c2 is the second radiation constant, and e is a constant; 5.

3. The industrial computer (10) calculates the calibration light power density S emitted by the optical radiation source (1) to the designated mid-infrared detector (14) to be calibrated: 5.

4. The industrial computer (10) calculates the response rate R of the designated mid-infrared detector (14) to be calibrated at the first temperature point through the electrical signal U:

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