A method and system for spectral crosstalk analysis of a multispectral infrared detector chip

Abstract

This application discloses a spectral crosstalk analysis method and system for a multispectral infrared detector chip, relating to infrared detector technology. The method, based on the principle of infrared radiation, calculates the number of radiated photons in different wavelength bands 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 wavelength range λ. start ~λ end The quantum efficiency within the range is approximately proportional; therefore, multiplying the photon number difference list with the corresponding photon spectrum list yields the wavelength range λ. start ~λ end The ratio of the response voltages within the main band is used to obtain the response voltage components. The crosstalk between bands is obtained by using the proportion of the response voltage components of other bands in the main band's response voltage. The method of this application can be used in detector screening to predict the crosstalk effect between bands during applications.

Description

Technical Field

[0001] This application relates to the field of infrared detector technology, and in particular to a method and system for spectral crosstalk analysis of a multispectral infrared detector chip. Background Technology

[0002] Since its discovery by humankind, infrared light 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 of infrared detectors has progressed 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, which is characterized by multi-spectral bands, high sensitivity, large array size, and low cost.

[0003] Multispectral infrared detector chips, integrating multiple spectral bands, are capable of identifying and detecting targets from multiple dimensions, improving detection accuracy. In practical applications, spectral overlap between multiple bands reduces the detection sensitivity of the infrared detector chip, making crosstalk suppression between spectral bands particularly important. Literature review revealed the area method for calculating crosstalk, which normalizes all spectral curves of multiple bands to a single coordinate system and calculates the crosstalk by proportionally scaling the overlapping areas. However, the area method has a drawback: it ignores the significant energy differences between different wavelengths. For example, at room temperature, long-wavelength radiation per unit area has more energy than medium-wavelength radiation, while long-wavelength single-photon energy is lower than medium-wavelength energy. Therefore, the number of long-wavelength photons radiating per unit area is much higher than that of medium-wavelength photons, resulting in significant errors when comparing crosstalk between different spectral bands using the area method. An accurate and effective method for calculating spectral crosstalk is crucial for crosstalk research. Summary of the Invention

[0004] This application provides a method and system for spectral crosstalk analysis of a multispectral infrared detector chip, which aims to propose a crosstalk method for multispectral infrared detector chips that meets the needs of practical applications.

[0005] This application provides a method for spectral crosstalk analysis of a multispectral infrared detector chip, including:

[0006] Measure the average response voltage of the detector assembly in each band, and, with the same acquisition step and acquisition range, ensure that the acquisition start and end points cover the entire spectrum of the response range. Measure the relative spectral response curves of the detector assembly in each band, and find the cutoff points of each band corresponding to the relative spectral response m (e.g., m is 0.5, or calculated according to other regulations) from the curves.

[0007] Based on Planck's blackbody radiation, the energy density of each wavelength emitted by the blackbody at different temperatures was calculated. The calculated energy density was then converted to the energy of a single photon to calculate the theoretical number of photons emitted by the blackbody that the detector could receive per unit parameter.

[0008] Based on the theoretically received blackbody emission photon count, a photon count list for the acquisition step interval is obtained; and, with temperatures T1 and T2 being the temperatures used for the average response voltage, a photon count difference list for the acquisition step interval is obtained.

[0009] Based on the photon number list and the photon number difference list, the response voltage components of the average response voltage of the detector component in each band before and after the cutoff are calculated respectively.

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

[0011] This application also proposes a spectral crosstalk analysis system for a multispectral infrared detector chip, including a processor and a memory. The memory stores a computer program, and when the computer program is executed by the processor, it implements the steps of the aforementioned spectral crosstalk analysis method for a multispectral infrared detector chip.

[0012] This application proposes a method for reducing crosstalk in multispectral infrared detector chips that meets practical application requirements.

[0013] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0014] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0015] Figure 1 This is a schematic diagram of the overall flow of the spectral crosstalk analysis method for the multispectral infrared detector chip in an embodiment of this application.

[0016] Figure 2 The difference curve of infrared radiation photon count between 308K and 293K is used as an application example in this application;

[0017] Figure 3 The curve showing the product of the difference in the number of infrared radiation photons and the quantum efficiency as an application example of this application. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0019] This application provides a method for spectral crosstalk analysis of a multispectral infrared detector chip, such as... Figure 1 As shown, it includes the following steps:

[0020] In step S101, the average response voltage of the detector assembly in each band is measured. For example, the average response voltage V of the detector assembly in all bands, such as A-band, B-band, and C-band, is measured according to method 3001 in GB / T17444-2013. SA V SB V SC And so on. Furthermore, following the same acquisition step and acquisition range, the acquisition start and end points must cover the entire spectral response range. The relative spectral response curves of the detector assembly in each band are measured, and the cutoff points for each band corresponding to the relative spectral response m (m is generally 0.5, unless otherwise specified) are found from the curves. For example, according to method 3010 in GB / T17444-2013, following the same acquisition step Δλ and acquisition range λ... start ~λ end The acquisition start and end points need to cover the entire spectral response range. The relative spectral response curves X(λ), Y(λ), and Z(λ) of the detector assembly in all bands, including A-band, B-band, and C-band, are measured respectively. The A-band front cutoff wavelength λ corresponding to the relative spectral response at point m is then found from the curves. A1 and the cutoff wavelength λ A2 B-band cutoff wavelength λ B1 and the cutoff wavelength λ B2 C-band cutoff wavelength λ C1 and the cutoff wavelength λ C2 Cut-off before and after the band.

[0021] In step S102, based on Planck blackbody radiation, the energy density of each wavelength band emitted by the blackbody at different temperatures is calculated. The calculated energy density is then converted to the energy of a single photon to calculate the theoretical number of photons emitted by the blackbody that the detector can receive per unit parameter.

[0022] In step S103, a photon count list for the acquisition step interval is obtained by refining the theoretical number of photons emitted by the blackbody, and the temperatures T1 and T2 (in specific applications, the infrared detector can be 293K and 308K, or calculated according to other regulations) are respectively V SA V SB V SC Based on the temperature used, a list N of photon number differences at the acquisition step interval Δλ is obtained. △ (λ).

[0023] Dividing the relative spectral response curves X(λ), Y(λ), and Z(λ) by λ respectively yields the relative photon spectrum lists x(λ), y(λ), and z(λ). N △ Multiplying (λ) and x(λ) separately yields list A(λ); N △ Multiply N(λ) and y(λ) separately to obtain list B(λ); △ Multiplying z(λ) and z(λ) separately yields the list C(λ), etc.

[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 component in each band before and after the cutoff are calculated respectively.

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

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

[0027]

[0028] Where M(λ, T) represents Planck's blackbody radiance, and h represents Planck's constant, 6.63 × 10⁻⁶. -34 J·s, where c represents the speed of light, 3 × 10⁻⁶ 8 m / s; K represents the Boltzmann constant, 1.38 × 10⁻⁶ m / s; -23 J / K.

[0029] In some embodiments, the calculated energy density is converted to the energy of a single photon to calculate the theoretical number of photons emitted by the blackbody that the detector can receive per unit parameter.

[0030] The calculated energy density M(λ, T) is converted to the energy E(λ) of a single photon and multiplied by the detector's field of view (FOV) to obtain the theoretical number of photons N(λ, T) emitted by the blackbody that the detector can receive per unit area and per unit integration time with a fixed acquisition step Δλ.

[0031]

[0032] Where F is the cold screen coefficient of the detector component.

[0033] In some embodiments, the photon count list for refining the acquisition step interval based on the theoretically received blackbody emission photon count includes: based on the theoretically received blackbody emission photon count N(λ,T), according to the acquisition step Δλ, from λ... start To λ end The process is refined to obtain a list of photon counts for each acquisition step interval.

[0034] In some embodiments, based on the photon number list and the photon number difference list, the average response voltage components of the detector component at the beginning and end of each band are calculated to satisfy the following:

[0035]

[0036] Where ΔU 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 , λ end The range of acquisition is defined by the start and end bands, and K(λ) represents a list of the corresponding bands.

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

[0038]

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

[0040]

[0041] In the formula:

[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 example of a spectral crosstalk analysis method for multispectral infrared detector chips, including the following steps:

[0049] Take one medium-to-long-wave dual-color detector component.

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

[0051] According to method 3010 in GB / T17444-2013, the same acquisition step Δλ (Δλ is 1.25 nm) and acquisition range λ are used. start ~λ end (2~13.5μm) The relative spectral response curves X(λ) and Y(λ) of the detector assembly in the mid-wave and long-wave bands were measured respectively. The mid-wave band front cutoff wavelength λ corresponding to the relative spectral response of 0.5 was found from the curves. A1 and the cutoff wavelength λ A2 Longwave band cutoff wavelength λ B1 and the cutoff wavelength λ B2 .

[0052] Based on Planck's blackbody radiation formula, single-photon energy formula, and field-of-view formula, the theoretical photon count curves for a detector with a sampling step of Δλ, unit area, and unit integration time are obtained. Substituting 293K and 308K, the photon count difference curve is obtained. Figure 2 As shown.

[0053]

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

[0055] Calculate the average response voltage V in the medium wave band respectively. SA In λ A1 and λ A2 The response voltage component ΔU of the band AA In λ B1 and λ B2 The response voltage component ΔU of the band AB and the average response voltage V in the long-wave band SB In λ A1 and λ A2 The response voltage component ΔU of the band BA In λ B1 and λ B2 The response voltage component ΔU of the band 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 from the long-wave B band to the mid-wave A band of the detector. BA The percentage is 0.0125 / 0.373 = 3.4%; spectral crosstalk CT from wave A to wave B in the detector. AB The value is 0.0015 / 0.198 = 0.8%.

[0061] In practical applications, the detector was observed to produce mid-wave imaging by placing a mid-wave filter in front of the detector's optical window, and to produce long-wave imaging by placing a long-wave filter in front of the detector's optical window. The results showed that the performance was very similar to that without a filter, indicating that there was little crosstalk in the application scenario, which is consistent with the crosstalk results calculated by the test.

[0062] The method of this application yields a detector component with low crosstalk, resulting in very low crosstalk between bands in practical applications; and a detector component with high crosstalk, resulting in significant crosstalk between bands in practical applications, which is in line with practical applications.

[0063] The method in this application is based on the principle of infrared radiation. It calculates the number of radiated photons in different wavelength bands 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 wavelength range λ. start ~λ end The quantum efficiency within the range is approximately proportional; therefore, multiplying the photon number difference list with the corresponding photon spectrum list yields the wavelength range λ. start ~λ end The ratio of the response voltages within the main band is used to obtain the response voltage components. Crosstalk between bands is obtained by using the proportion of the response voltage components of other bands within the main band's response voltage.

[0064] The method described in this application is closely aligned with practical application scenarios, and the calculated crosstalk level is proportional to the actual crosstalk interference in the application scenario. This method can be used in detector selection to predict the crosstalk effect between bands during application.

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

[0066] This application also proposes a spectral crosstalk analysis system for a multispectral infrared detector chip, including a processor and a memory. The memory stores a computer program, and when the computer program is executed by the processor, it implements the steps of the spectral crosstalk analysis method for the multispectral infrared detector chip as described above.

[0067] It should be noted that, in the embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0068] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0069] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0070] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.

Claims

1. A method for spectral crosstalk analysis of a multispectral infrared detector chip, characterized in that, include: The average response voltage of the detector component in each band was measured. Also, the relative spectral response curves of the detector component in each band were measured, and the cutoff points of each band corresponding to the relative spectral response m were found from the curves. Based on Planck's blackbody radiation, the energy density of each wavelength emitted by the blackbody at different temperatures was calculated. The calculated energy density was then converted to the energy of a single photon to calculate the theoretical number of photons emitted by the blackbody that the detector could receive per unit parameter. Based on the theoretically received blackbody emission photon count, a photon count list for the acquisition step interval is obtained; and, with temperatures T1 and T2 being the temperatures used for the average response voltage, a photon count difference list for the acquisition step interval is obtained. Based on the photon number list and the photon number difference list, the response voltage components of the average response voltage of the detector component in each band before and after the cutoff are calculated respectively. Based on the calculated average response voltage components of each band before and after cutoff, crosstalk in each band is determined. Based on the photon number list and the photon number difference list, the average response voltage of the detector component in each band is calculated, and the response voltage components before and after the cutoff satisfy the following: in, This represents the response voltage component of the corresponding frequency band. Indicates the corresponding wave in the band to band The average response voltage between , Indicates the start and end bands of the acquisition range. Indicates wavelength. A list representing the corresponding bands; Based on the calculated average response voltage components of each band before and after cutoff, the crosstalk between each band is determined as the ratio between the response voltage components between bands to the response voltage components of the band itself.

2. The spectral crosstalk analysis method for a multispectral infrared detector chip as described in claim 1, characterized in that, Based on Planck's blackbody radiation, the energy density of blackbody emission at different wavelengths at different temperatures is calculated to satisfy: Among them, M ( (T) represents Planck's blackbody radiation, where T is the blackbody temperature, h represents Planck's constant, and c represents the speed of light. K represents the Boltzmann constant.

3. The spectral crosstalk analysis method for a multispectral infrared detector chip as described in claim 2, characterized in that, By converting the calculated energy density to the energy of a single photon, the theoretical number of photons emitted by the blackbody and received by the detector per unit parameter can be calculated. The calculated energy density is converted to the energy of a single photon and multiplied by the detector's field of view (FOV) to obtain the theoretical number of photons N(λ,T) emitted by a blackbody that the detector can receive per unit area and per unit integration time with a fixed acquisition step Δλ. Where F is the cold screen coefficient of the detector assembly, and Δλ is the acquisition step. Indicates temperature change The Planck blackbody radiation is given by E(λ), where E(λ) is the energy of a single photon.

4. The spectral crosstalk analysis method for a multispectral infrared detector chip as described in claim 3, characterized in that, The list of photon counts for the acquisition step interval, obtained by refining the theoretically received photon count of blackbody emission, includes: Based on the theoretically received number of photons N(λ,T) emitted by the blackbody, according to the acquisition step Δ from start arrive end The process is refined to obtain a list of photon counts for each acquisition step interval.

5. A spectral crosstalk analysis system for a multispectral infrared detector chip, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program, which, when executed by the processor, implements the steps of the spectral crosstalk analysis method for the multispectral infrared detector chip as described in any one of claims 1 to 4.

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