Spectral crosstalk analysis method and system for multispectral infrared detector chip

Abstract

The invention discloses a spectral crosstalk analysis method and system of a multispectral infrared detector chip, and relates to the infrared detector technology, the method starts from the infrared radiation principle, the number of radiation photons of different wave bands is substituted for calculation, a relative photon spectrum list is obtained according to the relative spectral response of an infrared detector, and the relative photon spectrum list is used for analyzing the spectral crosstalk of the multispectral infrared detector chip. The relative photon spectrum list is approximately in direct proportion to the quantum efficiency in the wave band range lambda start-lambda end, so that the photon number difference list is correspondingly multiplied by the relative photon spectrum list, the ratio of the response voltage in the wave band range lambda start-lambda end can be obtained, and the response voltage component is obtained. And the crosstalk between the wavebands is obtained according to the response voltage ratio of the response voltage components of other wavebands in the main body waveband. The method provided by the invention can be used for predicting the crosstalk effect between wavebands during prejudgment application in detector screening.

Description

Technical Field

[0001] The present application relates to the field of infrared detector technology, and in particular to a spectral crosstalk analysis method and system for a multi-spectral infrared detector chip. Background Art

[0002] Since infrared light was discovered by humans, it has been gradually applied to various industries and sectors such as industry, agriculture, medicine, and transportation. After more than two centuries of development, the development stage of infrared detectors has developed from the first generation to the current second and third generations. After the emergence of a large family of infrared detector chips, research has focused on the third generation with multi-spectral bands, high sensitivity, large array and low cost as its technical characteristics.

[0003] Since multi-spectral infrared detector chips integrate multiple spectral bands, they are capable of identifying and detecting targets from multiple dimensions, which improves the accuracy of detection. In practical applications, if there is spectral overlap between multiple spectral bands, the detection sensitivity of the infrared detector chip imaging will be reduced. Therefore, the crosstalk suppression between the spectral bands of the multi-spectral infrared detector chip is particularly important. After literature research, it is found that there is an area method to calculate the crosstalk between spectra, that is, by normalizing all spectral curves of multiple spectral bands in the same coordinate system, and performing proportional calculations through the area of ​​overlapping areas to obtain the spectral crosstalk of multiple spectral bands. However, the area method has a disadvantage, which ignores the fact that the energy of different bands is very different. For example, at room temperature, the energy of long-wave radiation per unit area is more than that of medium-wave, while the energy of long-wave single photons is lower than that of medium-wave. Therefore, the number of photons radiated per unit area of ​​long-wave radiation is much more than that of medium-wave, resulting in a large error in the area method to compare the crosstalk of different spectral bands. An accurate and effective method for calculating spectral crosstalk is particularly important for crosstalk research. Summary of the invention

[0004] The embodiments of the present application provide a spectral crosstalk analysis method and system for a multi-spectral infrared detector chip, so as to propose a multi-spectral infrared detector chip crosstalk method that meets the actual application requirements.

[0005] The present application embodiment provides a spectral crosstalk analysis method for a multi-spectral infrared detector chip, comprising:

[0006] The average response voltage of the detector assembly in each band is measured respectively, and, according to the same acquisition step and acquisition range, the acquisition start and end points need to cover the response range of the entire spectrum, and the relative spectral response curve of the detector assembly in each band is measured respectively, and the front and rear cutoffs of each band corresponding to the relative spectral response of m (for example, m is 0.5, otherwise calculated in accordance with the regulations) are found from the curve;

[0007] According to Planck blackbody radiation, the energy density of each wavelength band emitted by the blackbody at different temperatures is calculated, and the calculated energy density is converted with the energy of a single photon to calculate the number of photons emitted by the blackbody that the detector theoretically receives under unit parameters;

[0008] Based on the theoretical number of photons emitted by the received black body, a list of photon numbers for the collected step intervals is obtained, and the temperatures T1 and T2 are respectively the temperatures used for the average response voltage, and a list of photon number differences for the collected step intervals is obtained;

[0009] Based on the photon number list and the photon number difference list, respectively calculate the response voltage components of the average response voltage of the detector assembly in each band before and after the cutoff;

[0010] The crosstalk in each band is determined based on the calculated response voltage components before and after the average response voltage of each band.

[0011] An embodiment of the present application also proposes a spectral crosstalk analysis system for a multi-spectral infrared detector chip, comprising a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of the spectral crosstalk analysis method for the multi-spectral infrared detector chip as described above are implemented.

[0012] The embodiment of the present application proposes a multi-spectral infrared detector chip crosstalk method that meets the actual application requirements.

[0013] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0015] Figure 1 The overall process diagram of the spectral crosstalk analysis method of the multi-spectral infrared detector chip of the embodiment of the present application is shown;

[0016] Figure 2 This is the difference curve of the number of infrared radiation photons at 308K and 293K used as an example in this application;

[0017] Figure 3 This is a product curve of the infrared radiation photon number difference and quantum efficiency for the application example of this application. DETAILED DESCRIPTION

[0018] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0019] The present application embodiment provides a spectral crosstalk analysis method for a multi-spectral infrared detector chip, such as Figure 1 As shown, the following steps are included:

[0020] In step S101, the average response voltage of the detector assembly in each band is measured respectively. For example, the average response voltage V of the detector assembly in all bands such as band A, band B, and band C is measured respectively according to method 3001 in GB / T17444-2013. SA 、V SB 、V SC Etc. And, according to the same acquisition step and acquisition range, the acquisition start and end points need to cover the response range of the entire spectrum, measure the relative spectral response curve of the detector component in each band, and find out the front and rear cutoffs of each band corresponding to the relative spectral response m (m is generally 0.5, otherwise calculated according to regulations) from the curve. For example, according to method 3010 in GB / T17444-2013, according to the same acquisition step △λ and acquisition range λ start ~λ end , the collection start and end points need to cover the response range of the entire spectrum, and the relative spectral response curves X(λ), Y(λ) and Z(λ) of the detector components in all bands such as A band, B band and C band are measured respectively, and the front cutoff wavelength λ of the A band corresponding to the relative spectral response m is found from the curve A1 and the rear cutoff wavelength λ A2 , B band front cut-off wavelength λ B1 and the rear cutoff wavelength λ B2 、C-band front cut-off wavelength λ C1 and the rear cutoff wavelength λ C2 Equal bands are cut off before and after.

[0021] In step S102, based on Planck blackbody radiation, the energy density of each wavelength band of blackbody emission at different temperatures is calculated, the calculated energy density is converted with the energy of a single photon, and the number of photons emitted by the blackbody theoretically received by the detector under unit parameters is calculated.

[0022] In step S103, a list of photon numbers of the collected step intervals is obtained based on the theoretical number of photons emitted by the received black body, and the temperatures T1 and T2 (in specific applications, the infrared detector can use 293K and 308K, otherwise calculated according to the regulations) are V SA 、V SB 、V SC The photon number difference list N of the acquisition step interval △λ is obtained by using the same temperature. △ (λ).

[0023] Divide the relative spectral response curves X(λ), Y(λ) and Z(λ) by λ to obtain the relative photon spectrum lists x(λ), y(λ) and z(λ). △ Multiply (λ) and x(λ) respectively to get the list A(λ); △ Multiply (λ) and y(λ) respectively to get the list B(λ); △ (λ) and z(λ) are multiplied respectively to obtain the list C(λ) and so on.

[0024] In step S104, based on the photon number list and the photon number difference list, the response voltage components of the average response voltage of the detector assembly in each band before and after the cutoff are calculated respectively;

[0025] In step S105, the crosstalk in each band is determined according to the calculated response voltage components before and after the average response voltage of each band.

[0026] In some embodiments, based on Planck blackbody radiation, the energy density M(λ, T) of each wavelength band of blackbody emission at different temperatures is calculated to satisfy:

[0027]

[0028] Where M(λ, T) represents the Planck blackbody radiation, and h represents the Planck constant, 6.63×10 -34 J·s, c represents the speed of light, 3×10 8 m / s; K represents the Boltzmann constant, 1.38×10 -23 J / K.

[0029] In some embodiments, the calculated energy density is converted to the energy of a single photon to calculate the number of photons emitted by the black body that the detector theoretically receives under unit parameters.

[0030] The calculated energy density M(λ, T) is converted to the energy E(λ) of a single photon and multiplied by the field of view FOV of the detector to obtain the number of photons N(λ, T) theoretically received by the detector at a fixed acquisition step △λ, unit area and unit integration time, where:

[0031]

[0032] Where F is the cold shield factor of the detector assembly.

[0033] In some embodiments, refining the photon number list of the collection step interval based on the theoretical number of photons emitted by the received black body includes: based on the theoretical number of photons emitted by the received black body N(λ,T), according to the collection step △λ from λ start to λ end Perform refinement to obtain a list of photon numbers for the acquisition step interval.

[0034] In some embodiments, based on the photon number list and the photon number difference list, the average response voltage of the detector assembly in each band is calculated respectively, and the response voltage components before and after the cutoff satisfy:

[0035]

[0036] Among them, △U represents the response voltage component of the corresponding band, V represents the average response voltage of the corresponding wave between band λ1 and band λ2, and λ start , end It represents the start and end bands of the acquisition range, and K(λ) represents the list of corresponding bands.

[0037] Specifically, the average response voltage V of the detector in the A band is calculated respectively. SA In λ A1 and λ A2 The response voltage component of the band △U AA , in λ B1 and λ B2 The response voltage component of the band △U AB and in λ C1 and λ C2 The response voltage component of the band △U AC , the average response voltage V of the detector in the B band SB In λ A1 and λ A2 The response voltage component of the band △U BA , in λ B1 and λ B2 The response voltage component of the band △U BB and in λ C1 and λ C2 The response voltage component of the band △U BC , and the average response voltage V of the detector in the C band SC In λ A1 and λ A2 The response voltage component of the band △U CA , in λ B1 and λ B2The response voltage component of the band △U CB and in λ C1 and λ C2 The response voltage component of the band △U CC etc., satisfying:

[0038]

[0039] In some embodiments, the crosstalk between the bands is determined as the ratio between the response voltage component between the bands and the response voltage component of the band itself according to the calculated response voltage component of the average response voltage of each band before and after the cutoff. Specifically, based on the above-mentioned embodiment, the crosstalk of the detector from the B band and C band to the A band, the crosstalk of the A band and C band to the B band, the crosstalk of the A band and B band to the C band, etc. are respectively:

[0040]

[0041] Where:

[0042] CT BA --Spectral crosstalk from detector B band to detector A band;

[0043] CT CA — Spectral crosstalk from detector C-band to detector A-band;

[0044] CT AB — Spectral crosstalk from detector A band to detector B band;

[0045] CT CB — Spectral crosstalk from detector C-band to detector B-band;

[0046] CT AC —Spectral crosstalk from detector A-band to detector C-band;

[0047] CT BC —Spectral crosstalk from detector B-band to detector C-band.

[0048] This application also proposes an implementation case of a spectral crosstalk analysis method for a multi-spectral infrared detector chip, comprising the following steps:

[0049] Take a medium- and long-wave dual-color detector assembly.

[0050] According to the method 3001 in GB / T17444-2013, the average response voltage V of the detector assembly in the medium wave band and the long wave band were measured respectively. SA and V SB They are 0.384mV and 0.262mV respectively.

[0051] According to method 3010 in GB / T17444-2013, with the same acquisition step △λ (△λ is 1.25nm) and acquisition range λ start ~λ end (2~13.5μm), measure the relative spectral response curves X(λ) and Y(λ) of the detector assembly in the medium wave band and long wave band respectively, and find out the front cut-off wavelength λ of the medium wave band corresponding to the relative spectral response of 0.5 from the curve. A1 and the rear cutoff wavelength λ A2 , long wave band front cut-off wavelength λ B1 and the rear cutoff wavelength λ B2 .

[0052] According to Planck's blackbody radiation formula, single photon energy formula and field angle formula, the photon number curve of the detector receiving the blackbody emission theoretically with the acquisition step △λ as the interval, unit area and unit integration time is obtained. 293K and 308K are brought in to obtain the photon number difference curve Figure 2 shown.

[0053]

[0054] Divide the relative spectral response curves X(λ) and Y(λ) by λ (approximately proportional to the quantum efficiency), and then multiply them by the photon number difference curves one by one. The new curves obtained are proportional to the response voltage, such as Figure 3 shown.

[0055] Calculate the average response voltage V in the medium wave band SA In λ A1 and λ A2 The response voltage component of the band △U AA , in λ B1 and λ B2 The response voltage component of the band △U AB and the average response voltage V in the long-wave band SB In λ A1 and λ A2 The response voltage component of the band △U BA , in λ B1 and λ B2 The response voltage component of the band △U BB .

[0056] △U AA =0.373mV;

[0057] △U AB =0.0015mV;

[0058] △U BA =0.0125mV;

[0059] △UBB =0.198mV.

[0060] The spectral crosstalk CT of the detector from the long-wave B band to the medium-wave A band is BA 0.0125 / 0.373=3.4%; spectral crosstalk CT from the detector medium wave A band to the long wave B band AB It is 0.0015 / 0.198=0.8%.

[0061] In actual applications, the medium-wave filter is placed in front of the detector optical window to observe medium-wave imaging, and the long-wave filter is placed in front of the detector optical window to observe long-wave imaging. It is found that the results are very similar to the situation without placing filters. It is believed that there is less crosstalk in the application scenario, which is consistent with the results of the test calculation of crosstalk.

[0062] The method of the present application obtains a detector component with low crosstalk, and in practical applications, the crosstalk between bands is very low; and obtains a detector component with large crosstalk, and in practical applications, the crosstalk between bands is obvious, which is suitable for practical applications.

[0063] The method of the embodiment of the present application starts from the principle of infrared radiation, brings in the number of radiation photons in different bands, performs calculations, and obtains a relative photon spectrum list based on the relative spectral response of the infrared detector. The relative photon spectrum list is related to the band range λ start ~λ end The quantum efficiency is approximately proportional to the photon number difference list and the relative photon spectrum list, so the band range λ can be obtained by multiplying the photon number difference list and the relative photon spectrum list. start ~λ end The crosstalk between bands is obtained by taking the ratio of the response voltage components of other bands to the response voltage of the main band.

[0064] The method of the present application is consistent with the actual application scenario, and the calculated crosstalk size can be proportional to the crosstalk in the actual application scenario. The present method can be used in the detector screening to predict the crosstalk effect between bands when predicting the application.

[0065] The method of the present application is particularly suitable for the calculation of crosstalk between different spectral bands, such as shortwave and medium wave, medium wave and long wave, etc. It makes full use of the differences in the number of photons and quantum efficiency between different spectral bands, and is more suitable for the actual application scenarios than the crosstalk of the area method.

[0066] An embodiment of the present application also proposes a spectral crosstalk analysis system for a multi-spectral infrared detector chip, comprising a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of the spectral crosstalk analysis method for the multi-spectral infrared detector chip as described above are implemented.

[0067] It should be noted that in the various embodiments of the present application, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0068] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0069] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0070] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A spectral crosstalk analysis method for a multi-spectral infrared detector chip, characterized in that: include: The average response voltage of the detector assembly in each band is measured respectively, and, according to the same acquisition step and acquisition range, the acquisition start and end points need to cover the response range of the entire spectrum, and the relative spectral response curve of the detector assembly in each band is measured respectively, and the front and rear cutoffs of each band corresponding to the relative spectral response m are found from the curve; According to Planck blackbody radiation, the energy density of each wavelength band emitted by the blackbody at different temperatures is calculated, and the calculated energy density is converted with the energy of a single photon to calculate the number of photons emitted by the blackbody that the detector theoretically receives under unit parameters; Based on the theoretical number of photons emitted by the received black body, a list of photon numbers for the collected step intervals is obtained, and the temperatures T1 and T2 are respectively the temperatures used for the average response voltage, and a list of photon number differences for the collected step intervals is obtained; Based on the photon number list and the photon number difference list, respectively calculate the response voltage components of the average response voltage of the detector assembly in each band before and after the cutoff; The crosstalk in each band is determined based on the calculated response voltage components before and after the average response voltage of each band.

2. The spectral crosstalk analysis method of the multi-spectral infrared detector chip according to claim 1, characterized in that: According to Planck blackbody radiation, the energy density of each wavelength band of blackbody emission at different temperatures is calculated to satisfy: Among them, M(λ, T) represents Planck's blackbody radiation, h represents Planck's constant, and c represents the speed of light. K represents the Boltzmann constant.

3. The spectral crosstalk analysis method of the multi-spectral infrared detector chip according to claim 2, characterized in that: Convert the calculated energy density to the energy of a single photon to calculate the number of photons emitted by the black body that the detector theoretically receives under unit parameters. The calculated energy density is converted to the energy of a single photon and multiplied by the field of view FOV of the detector to obtain the number of photons N(λ,T) theoretically received by the detector at a fixed acquisition step △λ, unit area and unit integration time, where: Where F is the cold shield factor of the detector assembly.

4. The spectral crosstalk analysis method of the multi-spectral infrared detector chip according to claim 3, characterized in that: The photon number list based on the theoretical received blackbody emission is refined to obtain the collection step interval, including: Based on the theoretical number of received blackbody emitted photons N(λ,T), the acquisition step △λ is calculated from λ start to λ end Perform refinement to obtain a list of photon numbers for the acquisition step interval.

5. The spectral crosstalk analysis method of the multi-spectral infrared detector chip according to claim 4, characterized in that: Based on the photon number list and the photon number difference list, the average response voltage of the detector assembly in each band is calculated respectively, and the response voltage components before and after the cutoff satisfy: Among them, △U represents the response voltage component of the corresponding band, V represents the average response voltage of the corresponding wave between band λ1 and band λ2, and λ start , end It represents the start and end bands of the acquisition range, and K(λ) represents the list of corresponding bands.

6. The spectral crosstalk analysis method of the multi-spectral infrared detector chip according to claim 4, characterized in that: According to the calculated response voltage components before and after the average response voltage of each band, the crosstalk between the bands is determined as the ratio between the response voltage components between the bands and the response voltage components of the band itself.

7. A spectrum crosstalk analysis system for a multi-spectral infrared detector chip, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the steps of the spectral crosstalk analysis method of the multi-spectral infrared detector chip as described in any one of claims 1 to 6 are implemented.

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