A method for fabricating a four-color focal plane detector and a method for acquiring four-color images.

Abstract

This invention discloses a method for fabricating a four-color focal plane detector and a method for acquiring four-color images. By designing the working wavelength ranges of the substrate, the first-color filter, and the second-color filter, a 2×2 grid periodically arranged four-color micro-filter array optical device is fabricated. The four-color micro-filter array optical device is suspended and integrated onto the focal plane of the detector to form a four-color focal plane detector. The four original monochrome images output by the four-color focal plane detector are subjected to image super-resolution reconstruction to obtain four full-resolution monochrome images. The four full-resolution monochrome images are then subjected to working wavelength deintersection processing to obtain four full-resolution monochrome images with no overlap in their working wavelengths. This invention enables the fabrication method and four-color image acquisition method of the four-color focal plane detector to simultaneously acquire four full-resolution monochrome images with no overlap in their working wavelengths. It has the advantages of simple manufacturing process, compact structure, high integration, snapshot imaging capability, and low cost.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic imaging technology, specifically relating to a method for manufacturing a four-color focal plane detector and a method for acquiring four-color images. Background Technology

[0002] Four-color imaging technology can simultaneously acquire spatial and four-color spectral information of a scene, thereby improving the ability of optoelectronic imaging systems to detect and identify targets under complex background conditions, and has important application value in the military field.

[0003] Four-color imaging systems are mainly classified into three categories based on their configuration: the first category consists of four single-band systems; the second category consists of an optical system and four detectors of different bands; and the third category uses a focal plane detector capable of simultaneously responding to four bands. The first two categories of four-color imaging systems are limited in application due to their large size, high cost, and susceptibility to spatial registration errors and poor reliability among the detectors. The third category of four-color imaging methods offers advantages such as high integration, miniaturization, and small spatial registration errors. The four-color focal plane detector is the core component of this third type of imaging system.

[0004] Currently, there are two main types of four-color focal plane array detectors: the first is the array-type, where adjacent pixels respond to different wavelengths, and the four types of pixels are arranged in an alternating pattern, making the fabrication process extremely difficult; the second is the stacked-type, which consists of four longitudinally distributed stacked photodiodes or infrared quantum wells, enabling the acquisition of radiation in four spatially aligned wavelengths. Four-color focal plane array detectors require achieving radiation response and signal readout for four wavelengths within a small space within a single pixel or adjacent pixels. This places extremely high demands on the design and fabrication processes of the detector's materials, device packaging, and readout circuitry, resulting in complex and expensive fabrication processes. In summary, existing four-color imaging methods suffer from drawbacks such as large system size, complex fabrication processes, and high costs.

[0005] Currently, the literature (Research on Design and Fabrication Process of Visible / Infrared Dual-Band Array Filter, 2007, 36(z1)) discloses a design and fabrication process for a dual-band array filter. This fabrication scheme completes the dual-band array filter by using two filter film deposition processes on a sapphire substrate, including the first process of depositing a long-pass infrared cutoff filter film and the second process of depositing a short-pass cutoff filter film. When implementing the second filter film deposition process, this fabrication scheme requires precise positioning of the filter film already deposited in the first process to ensure that the second deposition process does not affect the filter film already deposited in the first process. Otherwise, it will damage the filter film of the first deposition process, or even damage the filter film already deposited in the first process, thereby seriously reducing the overall quality, performance, and yield of the array filter. The literature (Research on Color Filter and Microlens Process Based on CMOS Image Sensor [J]. Integrated Circuit Application, 2020, 37(02):34-36) discloses a fabrication process for a color filter film with three colors: red, green, and blue. The manufacturing process involves three steps: making green, blue, and red filters. The placement and positioning of the photomasks are subject to strict requirements, making the manufacturing process quite challenging.

[0006] Therefore, how to manufacture four-color imaging devices that are simple in process, compact in structure, highly integrated, capable of snapshot imaging, and low in cost has become an urgent problem to be solved. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides a method for fabricating a four-color focal plane detector and a method for acquiring four-color images. The technical problem to be solved by this invention is achieved through the following technical solution:

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] This invention discloses a method for fabricating a four-color focal plane detector, comprising the following steps:

[0010] S11: The operating wavelength range of the design substrate, the first color filter, and the second color filter;

[0011] S12: Using the substrate, the first color filter film and the second color filter film, a four-color micro-filter array optical device with a 2×2 grid periodic arrangement is fabricated. The four-color micro-filter array optical device includes a plurality of four-color micro-filter unit blocks arranged in an array, wherein each of the four-color micro-filter unit blocks includes 2×2 micro-filter units.

[0012] S13: The four-color micro-filter array optical device is integrated into the focal plane of the focal plane detector in a suspended manner to form a four-color focal plane detector.

[0013] In a preferred embodiment of the present invention, the operating wavelength ranges of the substrate, the first color filter, and the second color filter satisfy the following constraints:

[0014] The operating wavelength range of the substrate covers the operating wavelength range of the focal plane detector.

[0015] The operating wavelength ranges of the first color filter and the second color filter overlap;

[0016] The union of the operating wavelength ranges of the first color filter and the second color filter is smaller than the operating wavelength range of the focal plane detector.

[0017] In the four-color microfilter array optical device, any two adjacent microfilters have different operating wavelength ranges.

[0018] In a preferred embodiment of the present invention, step S12 includes:

[0019] S121: Deposit multiple first-color filters arranged in a comb-like periodic pattern on a substrate;

[0020] S122: A plurality of second-color filters arranged in a comb-like periodic pattern are deposited on the substrate along the direction perpendicular to the extension direction of the first-color filter film to form a four-color micro-filter array optical device.

[0021] As a preferred embodiment of the present invention: the first color filter film and the second color filter film are distributed on the same surface or different surfaces of the substrate.

[0022] In a preferred embodiment of the present invention: multiple first-color filter films are arranged in a comb-like periodic pattern on the substrate surface, wherein the width of a single first-color filter film is equal to 1 / 2 of its arrangement period; multiple second-color filter films are arranged in a comb-like periodic pattern on the substrate surface, wherein the width of a single second-color filter film is equal to 1 / 2 of its arrangement period.

[0023] In a preferred embodiment of the present invention, step S13 includes:

[0024] S131: A boss is provided around the photosensitive surface of the focal plane of the focal plane detector, and the four-color micro-filter array optical device is placed on the boss of the focal plane detector so that there is an axial gap between the four-color micro-filter array optical device and the pixel array of the focal plane detector, wherein the four-color micro-filter array optical device is aligned with the pixel array of the focal plane detector, and each pixel of the focal plane detector is spatially aligned with a micro-filter.

[0025] S132: With the microfilter array and the pixel array of the focal plane detector aligned in relative position, the four-color focal plane detector is formed by applying adhesive to the side of the microfilter array optics and curing it.

[0026] This invention also provides a four-color image acquisition method, which is implemented using the four-color focal plane detector described in any of the above embodiments. The four-color image acquisition method includes the following steps:

[0027] S21: Under uniform illumination, obtain the average value of the output of each of the four types of pixels of the four-color focal plane detector prepared by the fabrication method of the four-color focal plane detector described in any of the above embodiments.

[0028] S22: Acquire the original image output by the four-color focal plane detector;

[0029] S23: Based on the original image output by the four-color focal plane detector, four full-resolution monochrome images are reconstructed using image super-resolution methods;

[0030] S24: Using the working band range deintersection processing method, four full-resolution monochrome images with no overlap in the working bands are deconstructed.

[0031] In a preferred embodiment of the present invention, step S21 includes:

[0032] The four-color focal plane detector is illuminated with uniform light whose operating wavelength range is located at the intersection of the operating wavelength ranges of the first color filter and the second color filter. Under the illumination condition of the four-color focal plane detector, the average value m1 of all pixel values ​​that are not affected by the first color filter and the second color filter is calculated; the average value m2 of all pixel values ​​that are affected only by the first color filter and not by the second color filter is calculated; the average value m3 of all pixel values ​​that are affected only by the second color filter and not by the first color filter is calculated; and the average value m4 of all pixel values ​​that are affected by the first color filter and the second color filter is calculated.

[0033] Step S22 includes:

[0034] The original image A1 is obtained from the pixels in the four-color focal plane detector that are not affected by the first color filter and the second color filter; the original image A2 is obtained from the pixels that are only affected by the first color filter and the second color filter; the original image A3 is obtained from the pixels that are only affected by the second color filter and the first color filter; and the original image A4 is obtained from the pixels that are affected by both the first color filter and the second color filter.

[0035] Step S23 includes:

[0036] The original images A1, A2, A3, and A4 are processed using an image super-resolution method to obtain full-resolution monochrome images B1, B2, B3, and B4, respectively.

[0037] Step S24 includes:

[0038] The four full-resolution monochrome images obtained in step S23 are subjected to working band range deintersection processing to obtain full-resolution monochrome images C1, C2, C3, and C4 whose working bands do not overlap. The deconstruction formula is as follows:

[0039] C4 = m1 / m4 * B4

[0040] C3 = m1 / m3 * B3 – C4

[0041] C2=m1 / m2*B2–C4

[0042] C1 = B1–C2–C3–C4.

[0043] As a preferred embodiment of the present invention, the image super-resolution method is any one of three types of methods: image interpolation, machine learning, and deep learning.

[0044] The beneficial effects of this invention are:

[0045] This invention designs the working wavelength range of the substrate, the first color filter, and the second color filter to fabricate a 2×2 grid-arranged four-color micro-filter array optical device. The four-color micro-filter array optical device is then suspended and integrated onto the focal plane of the detector to form a four-color focal plane detector. Image super-resolution reconstruction is performed on the four original monochrome images output by the four-color focal plane detector to obtain four full-resolution monochrome images. The working wavelength deintersection processing of these four full-resolution monochrome images yields four full-resolution monochrome images with no overlap in their working wavelengths. This invention enables the fabrication method of the four-color focal plane detector and the four-color image acquisition method to simultaneously acquire four full-resolution monochrome images with no overlap in their working wavelengths. It has the advantages of simple manufacturing process, compact structure, high integration, snapshot imaging capability, and low cost. Attached Figure Description

[0046] Figure 1 This is a flowchart of a method for fabricating a four-color focal plane detector and a method for acquiring four-color images proposed in this invention;

[0047] Figure 2This is a layered schematic diagram of a four-color micro-filter array optical device proposed in this invention;

[0048] Figure 3 This is a layered schematic diagram of a four-color focal plane detector proposed in this invention;

[0049] Figure 4 This is a schematic diagram of the working band range of four full-resolution monochrome images before the working band deintersection processing in Example 1;

[0050] Figure 5 This is a schematic diagram of the working band range of four full-resolution monochrome images after the working band deintersection processing in Example 1;

[0051] Figure 6 This is a schematic diagram of the working band range of four full-resolution monochrome images before the working band deintersection processing in Example 2;

[0052] Figure 7 This is a schematic diagram of the working band range of four full-resolution monochrome images after the working band deintersection processing in Example 2.

[0053] Explanation of reference numerals in the attached figures:

[0054] 101-Substrate; 102-First color filter film; 103-Second color filter film; 104-Four-color micro-filter array optical device; 105-Focal plane detector; 106-Pixel array of focal plane detector; 107-Boss; 108-Four-color focal plane detector.

[0055] W1B1 is the working band range corresponding to the full-resolution monochrome image B1 before the implementation of the working band deintersection processing; W1B2 is the working band range corresponding to the full-resolution monochrome image B2 before the implementation of the working band deintersection processing; W1B3 is the working band range corresponding to the full-resolution monochrome image B3 before the implementation of the working band deintersection processing; W1B4 is the working band range corresponding to the full-resolution monochrome image B4 before the implementation of the working band deintersection processing.

[0056] W1C1 is the working band range corresponding to the full-resolution monochrome image C1 after performing a working band deintersection processing; W1C2 is the working band range corresponding to the full-resolution monochrome image C2 after performing a working band deintersection processing; W1C3 is the working band range corresponding to the full-resolution monochrome image C3 after performing a working band deintersection processing; W1C4 is the working band range corresponding to the full-resolution monochrome image C4 after performing a working band deintersection processing.

[0057] W2B1 is the working band range corresponding to the full-resolution monochrome image B1 before the second working band deintersection processing; W2B2 is the working band range corresponding to the full-resolution monochrome image B2 before the second working band deintersection processing; W2B3 is the working band range corresponding to the full-resolution monochrome image B3 before the second working band deintersection processing; W2B4 is the working band range corresponding to the full-resolution monochrome image B4 before the second working band deintersection processing.

[0058] W2C1 is the working band range corresponding to the full-resolution monochrome image C1 after the second working band deintersection processing; W2C2 is the working band range corresponding to the full-resolution monochrome image C2 after the second working band deintersection processing; W2C3 is the working band range corresponding to the full-resolution monochrome image C3 after the second working band deintersection processing; W2C4 is the working band range corresponding to the full-resolution monochrome image C4 after the second working band deintersection processing. Detailed Implementation

[0059] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0060] The technical solutions in the embodiments of the present invention will be clearly and completely described below. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Example 1

[0062] Please see Figure 1 , Figure 2 and Figure 3 , Figure 1 This is a flowchart illustrating a method for fabricating a four-color focal plane detector and acquiring four-color images, as proposed in this invention. Figure 2 This is a layered schematic diagram of a four-color micro-filter array optical device proposed in this invention. Figure 3 This is a layered schematic diagram of a four-color focal plane detector proposed in this invention. This invention provides a method for fabricating a four-color focal plane detector, specifically for focal plane detectors operating in the 0.4-1.0 μm wavelength range. The method designs four-color focal plane detectors with wavelengths of 0.4-1.0 μm, 0.4-0.6 μm, 0.5-0.7 μm, and 0.5-0.6 μm. The fabrication method includes the following steps:

[0063] S11: The operating wavelength range of the design substrate, the first color filter, and the second color filter.

[0064] Specifically, in this embodiment, the focal plane detector 105 is a visible-near-infrared focal plane detector with an operating wavelength of 0.4-1.0 μm. The substrate 101 can be a glass substrate with an operating wavelength range covering 0.4-1.0 μm. K9 glass is preferred as the substrate, but K7 or F5 glass can also be used. The operating wavelength of the first color filter 102 is designed to be 0.4-0.6 μm, and the operating wavelength of the second color filter 103 is designed to be 0.5-0.7 μm. The intersection of the operating wavelength ranges of the first color filter and the second color filter is 0.5-0.6 μm.

[0065] S12: Fabricate an optical device with a 2×2 grid periodically arranged four-color microfilter array.

[0066] Specifically, such as Figure 2 As shown, multiple first-color filter films 102 arranged in a comb-like periodic pattern are deposited on the surface of a transparent glass substrate 101. On the surface where the first-color filter films 102 are deposited, multiple second-color filter films 103 arranged in a comb-like periodic pattern are deposited along the direction perpendicular to the extension direction of the first-color filter films 102. The extension directions of the first-color filter films 102 and the second-color filter films 103 are perpendicular to each other, forming a four-color microfilter array optical device 104. Any two adjacent 2×2 microfilter units in the four-color microfilter array optical device 104 have four operating wavelength bands: 0.4-1.0μm, 0.4-0.6μm, 0.5-0.7μm, and 0.5-0.6μm.

[0067] S13: A suspended integrated four-color micro-filter array optical device is used to the focal plane of the focal plane detector to form a four-color focal plane detector.

[0068] Specifically, such as Figure 3 As shown, in a preferred embodiment of the present invention: a four-color focal plane detector 108 is formed by using a suspended integrated four-color microfilter array optical device 104 to the focal plane of the focal plane detector 105, including the following steps:

[0069] S21: The flip-chip bonding machine is used to ensure that the four-color micro-filter array optical device 104 is aligned with the pixel array 106 of the focal plane detector 105, so that each pixel of the focal plane detector is spatially aligned with a micro-filter.

[0070] S22: Ceramic material protrusions 107 are provided around the photosensitive surface of the focal plane detector so that the axial gap between the four-color filter array optical device 104 and the pixel array 106 of the focal plane detector is less than 10μm after integration.

[0071] S23: With the microfilter array and the pixel array 106 of the focal plane detector aligned in relative position, adhesive is applied and cured on the side of the microfilter array optics 104.

[0072] In this embodiment of the invention, the working wavelength of the focal plane detector is 0.4-1.0 μm, and the working wavelength of the K9 glass substrate is 0.35-2.0 μm.

[0073] In this embodiment of the invention, multiple first-color filter films 102 are arranged in a comb-like periodic pattern on the surface of the substrate 101. The arrangement period of a single first-color filter film 102 is 10 μm, and the width of a single first-color filter film 102 is 5 μm. The width of a single first-color filter film 102 is equal to half of its arrangement period, that is, the width of a first-color filter film 102 is equal to the distance between two first-color filter films 102.

[0074] In this embodiment of the invention, multiple second-color filter films 103 are arranged in a comb-like periodic pattern on the surface of the substrate 101. The arrangement period of a single second-color filter film 103 is 10 μm, the width of a single second-color filter film 103 is 5 μm, and the width of a single monochromatic filter film 103 is equal to half of its arrangement period.

[0075] In this embodiment of the invention, the focal plane detector 105 can be a frame exposure CMOS focal plane detector with a working wavelength of 0.4-1.0μm. The array size of the frame exposure CMOS focal plane detector is 1280×1024, and the pixel size is 5μm×5μm.

[0076] In this embodiment of the invention, a flip-chip bonding machine is selected to ensure that the four-color microfilter array optical device 104 is aligned with the pixel array 106 of the focal plane detector 105, so that each pixel of the focal plane detector is spatially aligned with a microfilter.

[0077] In this embodiment of the invention, UV adhesive is applied to the side of the micro-filter array optical device 104 and cured by exposure to UV lamp.

[0078] Please see again Figure 1 This embodiment also proposes a four-color image acquisition method based on the four-color focal plane detector fabrication method described in the above embodiments. This four-color image acquisition method includes the following steps:

[0079] S31: Obtain the average output values ​​of the four types of pixels of the four-color focal plane detector under uniform illumination conditions. Using uniform light whose operating wavelength range intersects the operating wavelength ranges of the first-color filter 102 and the second-color filter 103 (in this embodiment, uniform light with an operating wavelength range of 0.5-0.6 μm is selected), under uniform illumination of the four-color focal plane detector, calculate the average output value m1 of all pixels not affected by the first-color filter 102 and not affected by the second-color filter 103; calculate the average output value m2 of all pixels only affected by the first-color filter 102 and not affected by the second-color filter 103; calculate the average output value m3 of all pixels only affected by the second-color filter 103 and not affected by the first-color filter 102; and calculate the average pixel value m4 of all pixels affected by both the first-color filter 102 and the second-color filter 103.

[0080] S32: Obtain the original image output by the four-color focal plane detector. In the four-color focal plane detector fabricated using the fabrication method of any of the above embodiments, the original image A1 output by pixels that are not affected by the first color filter 102 and the second color filter 103; the original image A2 output by pixels that are only affected by the first color filter 102 and not by the second color filter 103; the original image A3 output by pixels that are only affected by the second color filter 103 and not by the first color filter 102; and the original image A4 output by pixels that are affected by both the first color filter 102 and the second color filter 103.

[0081] S33: Reconstruct four full-resolution monochrome images using image super-resolution methods. Perform image super-resolution processing on the original images A1, A2, A3, and A4 respectively to obtain full-resolution monochrome images 1B1, 1B2, 1B3, and 1B4.

[0082] S34: Using the working band range deintersection processing method, four full-resolution monochrome images with no overlap in the working bands are deconstructed. The four full-resolution monochrome images are then subjected to working band range deintersection processing to obtain full-resolution monochrome images C1, C2, C3, and C4 with no overlap in their working bands.

[0083] Among them, the full-resolution monochrome image C4 is obtained by compensating for the transmittance attenuation of the first-color filter film 102 and the second-color filter film 103 from the full-resolution monochrome image B4. The specific decomposition formula is as follows:

[0084] C4 = m1 / m4 * B4

[0085] Among them, the full-resolution monochrome image C3 is obtained by two steps: compensating for the transmittance attenuation of the second-color filter film 103 and removing the C4 component of the full-resolution monochrome image B3. The specific decomposition formula is as follows:

[0086] C3 = m1 / m3 * B3 – C4

[0087] Among them, the full-resolution monochrome image C2 is obtained by two steps: compensating for the transmittance attenuation of the first-color filter 102 and removing the C4 component of the full-resolution monochrome image B2. The specific decomposition formula is as follows:

[0088] C2=m1 / m2*B2–C4

[0089] The full-resolution monochrome image C1 is obtained from the full-resolution monochrome image B1 by removing the C2 component, the C3 component, and the C4 component. The specific decomposition formula is as follows:

[0090] C1 = B1–C2–C3–C4

[0091] Specifically, in this embodiment, such as Figure 4 As shown:

[0092] W1B1 is the working band range corresponding to the full-resolution monochrome image B1 before the working band deintersection processing, with a value of 0.4-1.0μm;

[0093] W1B2 is the working band range corresponding to B2 of the full-resolution monochrome image before working band deintersection processing, with a value of 0.4-0.6μm;

[0094] W1B3 is the working band range corresponding to B3 of the full-resolution monochrome image before working band deintersection processing, with a value of 0.5-0.7μm;

[0095] W1B4 is the working band range corresponding to B4 of the full-resolution monochrome image before the working band deintersection processing, with a value of 0.5-0.6μm.

[0096] Specifically, in this embodiment, such as Figure 5 As shown:

[0097] W1C1 is the working band range corresponding to the full-resolution monochrome image C1 after the working band deintersection processing, with a value of 0.7-1.0μm;

[0098] W1C2 is the working band range corresponding to C2 of the full-resolution monochrome image after the working band deintersection processing, with a value of 0.4-0.5μm;

[0099] W1C3 represents the working band range corresponding to C3 in the full-resolution monochrome image after deintersection processing, with a value ranging from 0.6 to 0.7 μm.

[0100] W1C4 is the working band range corresponding to C4 of the full-resolution monochrome image after the working band deintersection processing, with a value of 0.5-0.6μm.

[0101] As a preferred embodiment of the present invention, the image super-resolution method is any one of the three types of methods: image interpolation, machine learning, and deep learning.

[0102] In this embodiment of the invention, the preferred image super-resolution method is the bilinear image interpolation method.

[0103] Example 2

[0104] Please see Figure 1 , Figure 2 and Figure 3 , Figure 1 This is a flowchart illustrating a method for fabricating a four-color focal plane detector and acquiring four-color images, as proposed in this invention. Figure 2 This is a layered schematic diagram of a four-color micro-filter array optical device proposed in this invention. Figure 3 This is a layered schematic diagram of a four-color focal plane detector proposed in this invention. This invention provides a method for fabricating a four-color focal plane detector. Specifically, for a wide-band infrared focal plane detector with an operating wavelength range of 0.4-3.0 μm, an embodiment of a four-color focal plane detector with operating wavelengths of 0.4-3.0 μm, 0.4-1.0 μm, 0.7-2.0 μm, and 0.7-1.0 μm is designed. The method for fabricating this four-color focal plane detector includes the following steps:

[0105] S11: The operating wavelength range of the design substrate, the first color filter, and the second color filter.

[0106] Specifically, in this embodiment, the focal plane detector 105 is a wide-band focal plane detector with a working wavelength range of 0.4-3.0 μm. The substrate 101 can be a glass substrate with a working wavelength range covering 0.4-3.0 μm. The substrate 101 is preferably made of calcium fluoride (CaF2) material, but sapphire (Al2O3) crystal material can also be used as the substrate. The working wavelength range of the first color filter 102 is designed to be 0.4-1.0 μm, and the working wavelength range of the second color filter 103 is designed to be 0.7-2.0 μm; the intersection of the working wavelength ranges of the first color filter and the second color filter is 0.7-1.0 μm.

[0107] S12: Fabricate an optical device with a 2×2 grid periodically arranged four-color microfilter array.

[0108] Specifically, such as Figure 2 As shown, multiple first-color filter films 102 arranged in a comb-like periodic pattern are deposited on the surface of a transparent glass substrate 101. On the surface where the first-color filter films 102 are deposited, multiple second-color filter films 103 arranged in a comb-like periodic pattern are deposited along the direction perpendicular to the extension direction of the first-color filter films 102. The extension directions of the first-color filter films 102 and the second-color filter films 103 are perpendicular to each other, forming a four-color microfilter array optical device 104. Any two adjacent 2×2 microfilter units in the four-color microfilter array optical device 104 have four operating wavelength bands: 0.4-3.0 μm, 0.4-1.0 μm, 0.7-2.0 μm, and 0.7-1.0 μm.

[0109] S13: A suspended integrated four-color micro-filter array optical device is used to the focal plane of the focal plane detector to form a four-color focal plane detector.

[0110] Specifically, such as Figure 3 As shown, in a preferred embodiment of the present invention: a four-color focal plane detector 108 is formed by using a suspended integrated four-color microfilter array optical device 104 to the focal plane of the focal plane detector 105, including the following steps:

[0111] S21: The flip-chip bonding machine is used to ensure that the four-color micro-filter array optical device 104 is aligned with the pixel array 106 of the focal plane detector 105, so that each pixel of the focal plane detector is spatially aligned with a micro-filter.

[0112] S22: Ceramic material protrusions 107 are provided around the photosensitive surface of the focal plane detector, so that the axial gap between the four-color filter array optical device 104 and the pixel array 106 of each focal plane detector is greater than 1μm and less than 30μm.

[0113] S23: With the microfilter array and the pixel array 106 of the focal plane detector aligned in relative position, adhesive is applied and cured on the side of the microfilter array optics 104.

[0114] In this embodiment of the invention, the working wavelength of the focal plane detector is 0.4-3.0 μm, and the working wavelength of the calcium fluoride CaF2 glass substrate is 0.23-9.7 μm.

[0115] In this embodiment of the invention, multiple first-color filter films 102 are arranged in a comb-like period on the surface of the substrate 101. The arrangement period of a single first-color filter film 102 is 30 μm, the width of a single first-color filter film 102 is 15 μm, and the width of a single first-color filter film 102 is equal to 1 / 2 of its arrangement period.

[0116] In this embodiment of the invention, multiple second-color filter films 103 are arranged in a comb-like periodic pattern on the surface of the substrate 101. The arrangement period of a single second-color filter film 103 is 30 μm, the width of a single second-color filter film 103 is 15 μm, and the width of a single second-color filter film 103 is equal to half of its arrangement period.

[0117] In this embodiment of the invention, the focal plane detector 105 can be an MCT focal plane detector with a working wavelength of 0.4-3.0 μm, an array size of 320×240, and a pixel size of 15 μm×15 μm.

[0118] In this embodiment of the invention, a flip-chip bonding machine is selected to ensure that the four-color microfilter array optical device 104 is aligned with the pixel array 106 of the focal plane detector 105, so that each pixel of the focal plane detector is spatially aligned with a microfilter.

[0119] In this embodiment of the invention, UV adhesive is applied to the side of the micro-filter array optical device 104 and cured by exposure to UV lamp.

[0120] Please see again Figure 1 This embodiment also proposes a four-color image acquisition method based on the four-color focal plane detector fabrication method described in the above embodiments. This four-color image acquisition method includes the following steps:

[0121] S31: Obtain the average output values ​​of the four types of pixels of the four-color focal plane detector under uniform illumination conditions. Using uniform light whose operating wavelength range intersects the operating wavelength ranges of the first-color filter 102 and the second-color filter 103 (in this embodiment, uniform light with an operating wavelength range of 0.7-1.0 μm is required), under uniform illumination of the four-color focal plane detector, calculate the average value m1 of all pixel values ​​that are not affected by the first-color filter 102 and the second-color filter 103; calculate the average value m2 of all pixel values ​​that are only affected by the first-color filter 102 and not affected by the second-color filter 103; calculate the average value m3 of all pixel values ​​that are only affected by the first-color filter 102 and not affected by the second-color filter 103; and calculate the average value m4 of all pixel values ​​that are affected by both the first-color filter 102 and the second-color filter 103.

[0122] S32: Obtain the original image output by the four-color focal plane detector. In the four-color focal plane detector fabricated using the fabrication method of any of the above embodiments, the original image A1 output by pixels that are not affected by the first color filter 102 and the second color filter 103; the original image A2 output by pixels that are only affected by the first color filter 102 and not by the second color filter 103; the original image A3 output by pixels that are only affected by the second color filter 103 and not by the first color filter 102; and the original image A4 output by pixels that are affected by both the first color filter 102 and the second color filter 103.

[0123] S33: Reconstruct four full-resolution monochrome images using image super-resolution methods. Perform image super-resolution processing on the original images A1, A2, A3, and A4 respectively to obtain full-resolution monochrome images B1, B2, B3, and B4.

[0124] S34: Using the working band range deintersection processing method, four full-resolution monochrome images with no overlap in the working bands are deconstructed. The four full-resolution monochrome images are then subjected to working band range deintersection processing to obtain full-resolution monochrome images C1, C2, C3, and C4 with no overlap in their working bands.

[0125] Among them, the full-resolution monochrome image C4 is obtained by compensating for the transmittance attenuation of the first-color filter film 102 and the second-color filter film 103 from the full-resolution monochrome image B4. The specific decomposition formula is as follows:

[0126] C4 = m1 / m4 * B4

[0127] Among them, the full-resolution monochrome image C3 is obtained by two steps: compensating for the transmittance attenuation of the second-color filter film 103 and removing the C4 component of the full-resolution monochrome image B3. The specific decomposition formula is as follows:

[0128] C3 = m1 / m3 * B3 – C4

[0129] Among them, the full-resolution monochrome image C2 is obtained by two steps: compensating for the transmittance attenuation of the first-color filter 102 and removing the C4 component of the full-resolution monochrome image B2. The specific decomposition formula is as follows:

[0130] C2=m1 / m2*B2–C4

[0131] The full-resolution monochrome image C1 is obtained from the full-resolution monochrome image B1 by removing the C2 component, the C3 component, and the C4 component. The specific decomposition formula is as follows:

[0132] C1 = B1–C2–C3–C4

[0133] Specifically, in this embodiment, such as Figure 6 As shown:

[0134] W2B1 is the working band range corresponding to the full-resolution monochrome image B1 before the working band deintersection processing, with a value of 0.4-3.0μm;

[0135] W2B2 is the working band range corresponding to B2 of the full-resolution monochrome image before working band deintersection processing, with a value of 0.4-1.0μm;

[0136] W2B3 is the working band range corresponding to B3 of the full-resolution monochrome image before working band deintersection processing, with a value of 0.7-2.0μm;

[0137] W2B4 is the working band range corresponding to B4 of the full-resolution monochrome image before working band deintersection processing, with a value of 0.7-1.0μm;

[0138] Specifically, in this embodiment, such as Figure 7 As shown:

[0139] W2C1 is the working band range corresponding to C1 of the full-resolution monochrome image after working band deintersection processing, with a value of 2.0-3.0μm;

[0140] W2C2 is the working band range corresponding to C2 of the full-resolution monochrome image after working band deintersection processing, with a value of 0.4-0.7μm;

[0141] W2C3 represents the working band range corresponding to C3 in the full-resolution monochrome image after deintersection processing, with a value ranging from 1.0 to 2.0 μm.

[0142] W2C4 is the working band range corresponding to C4 of the full-resolution monochrome image after working band deintersection processing, with a value of 0.7-1.0μm.

[0143] As a preferred embodiment of the present invention, the image super-resolution method is any one of the three types of methods: image interpolation, machine learning, and deep learning.

[0144] In this embodiment of the invention, the preferred image super-resolution method is the bicubic spline image interpolation method.

[0145] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art. The invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0146] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. These changes involve related technologies well known to those skilled in the art, and all of them fall within the protection scope of the present invention.

[0147] Many other changes and modifications can be made without departing from the concept and scope of this invention. It should be understood that this invention is not limited to the specific embodiments, and the scope of this invention is defined by the appended claims.

Claims

1. A method for manufacturing a four-color focal plane detector, characterized in that, Includes the following steps: S11: Design the operating wavelength ranges of the substrate, the first-color filter, and the second-color filter; the constraints satisfied by the operating wavelength ranges of the substrate, the first-color filter, and the second-color filter include: the operating wavelength range of the substrate covers the operating wavelength range of the focal plane detector; the operating wavelength ranges of the first-color filter and the second-color filter have an intersection; the union of the operating wavelength ranges of the first-color filter and the second-color filter is less than the operating wavelength range of the focal plane detector; S12: Using the substrate, the first-color filter film, and the second-color filter film, a 2×2 grid-arranged four-color microfilter array optical device is fabricated. The four-color microfilter array optical device includes multiple four-color microfilter unit blocks arranged in an array, wherein each four-color microfilter unit block includes 2×2 microfilter units; any two adjacent microfilters in the four-color microfilter array optical device have different operating wavelength ranges; step S12 includes: S121: depositing multiple first-color filter films arranged in a comb-like periodic pattern on the substrate; S122: depositing multiple second-color filter films arranged in a comb-like periodic pattern on the substrate along the direction perpendicular to the extension direction of the first-color filter film to form a four-color microfilter array optical device; S13: The four-color micro-filter array optical device is integrated into the focal plane of the focal plane detector in a suspended manner to form a four-color focal plane detector.

2. The method for manufacturing a four-color focal plane detector according to claim 1, characterized in that, The first color filter and the second color filter are distributed on either the same surface or different surfaces of the substrate.

3. The method for manufacturing a four-color focal plane detector according to claim 1, characterized in that, Multiple first-color filters are arranged in a comb-like periodic pattern on the substrate surface, wherein the width of a single first-color filter is equal to 1 / 2 of its arrangement period; multiple second-color filters are arranged in a comb-like periodic pattern on the substrate surface, wherein the width of a single second-color filter is equal to 1 / 2 of its arrangement period.

4. The method for manufacturing a four-color focal plane detector according to claim 1, characterized in that, Step S13 includes: S131: A boss is provided around the photosensitive surface of the focal plane of the focal plane detector, and the four-color micro-filter array optical device is placed on the boss of the focal plane detector so that there is an axial gap between the four-color micro-filter array optical device and the pixel array of the focal plane detector, wherein the four-color micro-filter array optical device is aligned with the pixel array of the focal plane detector, and each pixel of the focal plane detector is spatially aligned with a micro-filter. S132: With the microfilter array and the pixel array of the focal plane detector aligned in relative position, the four-color focal plane detector is formed by applying adhesive to the side of the microfilter array optics and curing it.

5. A method for acquiring a four-color image, characterized in that, Includes the following steps: S21: Under uniform illumination, obtain the average value of the output of each of the four types of pixels of the four-color focal plane detector prepared by the manufacturing method of any one of claims 1 to 4. S22: Acquire the original image output by the four-color focal plane detector; S23: Based on the original image output by the four-color focal plane detector, four full-resolution monochrome images are reconstructed using image super-resolution methods; S24: Using the working band range deintersection processing method, four full-resolution monochrome images with no overlap in the working band are deconstructed; Step S21 includes: The four-color focal plane detector is illuminated with uniform light whose operating wavelength range is located at the intersection of the operating wavelength ranges of the first color filter and the second color filter. Under the illumination condition of the four-color focal plane detector, the average value m1 of all pixel values ​​that are not affected by the first color filter and the second color filter is calculated; the average value m2 of all pixel values ​​that are only affected by the first color filter and not affected by the second color filter is calculated; the average value m3 of all pixel outputs that are not affected by the first color filter and only affected by the second color filter is calculated; and the average value m4 of all pixel values ​​that are affected by the first color filter and the second color filter is calculated. Step S22 includes: The original image A1 is obtained from the pixels in the four-color focal plane detector that are not affected by the first color filter and the second color filter; the original image A2 is obtained from the pixels that are only affected by the first color filter and the second color filter; the original image A3 is obtained from the pixels that are only affected by the second color filter and the first color filter; and the original image A4 is obtained from the pixels that are affected by both the first color filter and the second color filter. Step S23 includes: The original images A1, A2, A3, and A4 are processed using an image super-resolution method to obtain full-resolution monochrome images B1, B2, B3, and B4, respectively. Step S24 includes: The four full-resolution monochrome images obtained in step S23 are subjected to working band range deintersection processing to obtain full-resolution monochrome images C1, C2, C3, and C4 whose working bands do not overlap. The deconstruction formula is as follows: C4 = m1 / m4 * B4 C3 = m1 / m3 * B3 - C4 C2 = m1 / m2 * B2 - C4 C1 = B1 - C2 - C3 - C4.

6. The four-color image acquisition method according to claim 5, characterized in that, The image super-resolution method can be any one of the three types of methods: image interpolation, machine learning, or deep learning.

Images