Spectral imaging device

Abstract

The utility model provides a spectral imaging device which comprises a light splitting structure and a light sensing unit, the light splitting structure comprises at least two filtering units, and the at least two filtering units are sequentially stacked along a first direction, so that the spectral imaging device can capture and separate finer spectral bands, overlapping between adjacent bands of spectral imaging is avoided, and the spectral imaging efficiency is improved. The spectral imaging quality can be improved. And each filtering unit comprises a liquid crystal part, a first grating part and a second grating part, so that propagation and filtering of light can be accurately regulated and controlled, and an image with high spectral resolution is obtained. The optical properties of the liquid crystal part can be regulated and controlled by applying voltage, which means that the transmission or reflection characteristics of the filtering unit can be regulated as required. The light sensing unit is designed to be used for obtaining the light signals filtered by the light splitting structure and converting the light signals into electric signals, effective utilization of the light signals is ensured, and the conversion process is efficient and accurate. Therefore, high-quality original data is provided for subsequent data processing and analysis.

Description

Technical Field

[0001] The utility model relates to the technical field of spectral imaging, in particular to a spectral imaging device. Background Art

[0002] The spectral curve corresponding to each pixel obtained by hyperspectral imaging will directly reflect the spectral characteristics of the observed object, identify various camouflaged targets, and detect the target radiation energy in more detail than traditional cameras or imagers. At present, hyperspectral imaging has extremely high requirements for spectral segmentation capabilities.

[0003] In the related art, the wavelength range of light separated by the spectroscopic structure of hyperspectral imaging is relatively wide, resulting in overlap between adjacent bands of hyperspectral imaging and poor imaging quality. Utility Model Content

[0004] The embodiments of the utility model provide a spectral imaging device, which can improve the technical problem in the related art that the wavelength range of light separated by the spectroscopic structure of hyperspectral imaging is relatively wide, resulting in overlap between adjacent bands of hyperspectral imaging and poor imaging quality.

[0005] In a first aspect, an embodiment of the present utility model provides a spectral imaging device.

[0006] In one embodiment, the spectral imaging device comprises:

[0007] A light splitting structure, comprising at least two filter units, wherein the at least two filter units are stacked in sequence along a first direction, each of the filter units comprises a liquid crystal portion, a first grating portion and a second grating portion, wherein the liquid crystal portion is suitable for being applied with a voltage, and along the first direction, the first grating portion and the second grating portion are respectively located on two opposite sides of the liquid crystal portion and are both in contact with the side surfaces corresponding to the liquid crystal portion;

[0008] The photosensitive unit is arranged relative to the light splitting structure, and is used to obtain the light signal filtered by the light splitting structure and is suitable for converting the light signal into an electrical signal.

[0009] In one embodiment, when voltage is applied to the liquid crystal parts of the at least two filter units, the deflection angles of the liquid crystals of at least two of the liquid crystal parts are different, so that part of the light signal filtered out by one of the filter units is suitable for being filtered out by the other filter unit.

[0010] In one embodiment, the liquid crystal portion includes ultrafast ferroelectric liquid crystal.

[0011] In one embodiment, each of the at least two filter units is suitable for passing optical signals with a preset range of wavelengths, wherein the preset ranges of wavelengths of the at least two filter units have an intersection range, and the intersection range is: a≤λ≤b, wherein λ represents the wavelength, a and b are constants, and 0nm <b-a≤1nm。

[0012] In one embodiment, the duty cycle of the first grating portion is B1, wherein 0.3≤B1≤0.7; and / or,

[0013] The duty cycle of the second grating portion is B2, wherein 0.3≤B2≤0.7.

[0014] In one embodiment, the period of the first grating portion is T1, wherein 0.1um≤T1≤0.2um; and / or,

[0015] The period of the second grating portion is T2, wherein 0.1um≤T2≤0.2um.

[0016] In one embodiment, the first grating portion includes a first substrate and a plurality of first metal grating strips, the plurality of first metal grating strips are disposed on a first end surface of the first substrate, the plurality of first metal grating strips are arranged at equal intervals, and each of the first metal grating strips is extended along the second direction; and,

[0017] The second grating portion includes a second substrate and a plurality of second metal grating strips, wherein the plurality of second metal grating strips are arranged on the second end surface of the second substrate, the plurality of second metal grating strips are arranged at equal intervals, and each of the second metal grating strips extends along a third direction, wherein the third direction is perpendicular to the first direction, and the third direction is also perpendicular to the second direction.

[0018] In one embodiment, the thickness of the first substrate is H1, wherein 0.2um≤H1≤0.7um; and / or,

[0019] The thickness of the second substrate is H2, wherein 0.2um≤H2≤0.7um.

[0020] In one embodiment, the thickness of the first metal grating strip is H3, wherein 0.05um≤H3≤0.3um; and / or,

[0021] The thickness of the second metal grating strip is H4, wherein 0.05um≤H4≤0.3um.

[0022] In one embodiment, in two adjacent filter units, the first grating portion of one filter unit is attached to the first grating portion of the other filter unit, and along the first direction, the orthographic projections of the first metal grating strips of the two attached first grating portions at least partially overlap.

[0023] Beneficial effects of the embodiments of the utility model:

[0024] In the embodiment of the utility model, since each filter unit includes a liquid crystal part, a first grating part and a second grating part, the combined use of these elements can realize the accurate screening of different wavelength components in the optical signal. After the voltage is applied to the liquid crystal part, its optical properties (such as refractive index) will change, so that it can selectively transmit or reflect light of a specific wavelength. Through the stacking of multiple filter units, the optical signal will be screened by each filter unit in turn. This design can gradually narrow the wavelength range of the optical signal, so that the output optical signal has a narrower wavelength range, avoiding the overlap between adjacent bands in spectral imaging. The liquid crystal part can adjust its optical properties by applying different voltages, which makes the spectroscopic structure highly flexible. By adjusting the voltage, accurate control of optical signals of different wavelengths can be achieved to meet different application requirements. Since each filter unit can accurately screen and adjust the optical signal, the entire spectroscopic structure has a higher resolution. This helps to improve the quality and accuracy of spectral imaging. Multiple filter units are stacked in sequence along the first direction, so that the entire spectroscopic structure has a compact design. This is conducive to reducing the volume of the spectral imaging device and improving its portability and practicality. The photosensitive unit is designed to receive the light signal after filtering by the spectroscopic structure. Since the spectroscopic structure has already performed wavelength screening on the original light signal, the photosensitive unit can accurately capture the light signal within a specific wavelength range, which helps to improve the accuracy and reliability of imaging. By accurately capturing and efficiently converting light signals, the photosensitive unit can provide clearer and more accurate image data. This is crucial for applications such as spectral imaging that require high-resolution and high-precision images. Since the photosensitive unit is one of the key components of the imaging system, the stability and reliability of its performance have an important impact on the entire system. By setting the photosensitive unit relative to the spectroscopic structure, the optical path between them can be ensured to be stable, reducing the interference of external factors on the imaging quality, and improving the quality of spectral imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is one of the structural schematic diagrams of the light splitting structure provided in the embodiment of the utility model;

[0027] Figure 2 This is the second structural schematic diagram of the light splitting structure provided by the embodiment of the utility model;

[0028] Figure 3 It is a three-dimensional schematic diagram of a filter unit (liquid crystal deflection) provided in an embodiment of the utility model;

[0029] Figure 4 yes Figure 3 A left side view of the filter unit shown;

[0030] Figure 5 yes Figure 3 A right side view of the filter unit shown;

[0031] Figure 6 It is a three-dimensional schematic diagram of a filter unit (liquid crystal not deflected) provided in an embodiment of the utility model.

[0032] Description of Figure Numbers:

[0033] 100. Spectral structure;

[0034] 110, filter unit, 111, liquid crystal portion, 1111, liquid crystal, 1112, liquid crystal unit, 1113, main body, 1114, positive electrode column, 1115, negative electrode column;

[0035] 112, a first grating portion, 1121, a first substrate, 1122, a first metal grating strip;

[0036] 113. A second grating portion, 1131. A second substrate, 1132. A second metal grating strip. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0038] Combine the following Figures 1 to 6 The spectral imaging device of the present application is described.

[0039] The spectral imaging device includes a light splitting structure 100 and a photosensitive unit.

[0040] Reference Figures 1 to 3 The spectroscopic structure 100 includes at least two filter units 110, which are stacked in sequence along a first direction. Each filter unit 110 includes a liquid crystal portion 111, a first grating portion 112 and a second grating portion 113. The liquid crystal portion 111 is suitable for being applied with a voltage. Along the first direction, the first grating portion 112 and the second grating portion 113 are respectively located on two opposite sides of the liquid crystal portion 111 and are both in contact with the side surfaces corresponding to the liquid crystal portion 111. The photosensitive unit is arranged relative to the spectroscopic structure 100, and is used to obtain the optical signal after filtering by the spectroscopic structure 100 and is suitable for converting the optical signal into an electrical signal.

[0041] In the embodiment of the utility model, since each filter unit 110 includes a liquid crystal part 111, a first grating part 112 and a second grating part 113, the combined use of these elements can realize accurate screening of different wavelength components in the optical signal. After the voltage is applied to the liquid crystal part 111, its optical properties (such as refractive index) will change, so that it can selectively transmit or reflect light of a specific wavelength. Through the stacking of multiple filter units 110 in sequence, the optical signal will be screened by each filter unit 110 in sequence. This design can gradually narrow the wavelength range of the optical signal, so that the output optical signal has a narrower wavelength range, avoiding the overlap between adjacent bands in spectral imaging. The liquid crystal part 111 can adjust its optical properties by applying different voltages, which makes the light splitting structure 100 highly flexible. By adjusting the voltage, accurate control of light signals of different wavelengths can be achieved to meet different application requirements. Since each filter unit 110 can accurately screen and adjust the optical signal, the entire light splitting structure 100 has a higher resolution. This helps to improve the quality and accuracy of spectral imaging. A plurality of filtering units 110 are stacked in sequence along the first direction, so that the entire spectroscopic structure 100 has a compact design. This is conducive to reducing the volume of the spectral imaging device and improving its portability and practicality. The photosensitive unit is designed to receive the optical signal filtered by the spectroscopic structure 100. Since the spectroscopic structure 100 has already performed wavelength screening on the original optical signal, the photosensitive unit can accurately capture the optical signal within a specific wavelength range, which helps to improve the accuracy and reliability of imaging. By accurately capturing and efficiently converting the optical signal, the photosensitive unit can provide clearer and more accurate image data. This is crucial for applications such as spectral imaging that require high-resolution and high-precision images. Since the photosensitive unit is one of the key components of the imaging system, the stability and reliability of its performance have an important impact on the entire system. By arranging the photosensitive unit relative to the spectroscopic structure 100, the optical path between them can be ensured to be stable, the interference of external factors on the imaging quality can be reduced, and the spectral imaging quality can be improved.

[0042] Reference Figure 3In one embodiment, when the liquid crystal parts 111 of at least two filter units 110 are applied with voltage, the deflection angles of the liquid crystals 1111 of at least two liquid crystal parts 111 are different, so that part of the light signal filtered by one of the filter units 110 is suitable for being filtered by another filter unit 110. In this way, by adjusting the deflection angles of the liquid crystals 1111 of different liquid crystal parts 111, the transmission or reflection characteristics of each filter unit 110 for light signals of different wavelengths can be controlled. This continuous filtering design can more effectively separate and extract subtle spectral differences, thereby improving the resolution of spectral imaging. Since each filter unit 110 can filter for a specific spectral band, a wider spectral range can be covered by continuous filtering of multiple filter units 110. Through continuous filtering, each filter unit 110 can perform certain preprocessing on the light signal. This helps to reduce background noise, enhance target signals, etc., thereby improving the signal processing capability of the entire spectral imaging device. Since each filter unit 110 can accurately filter for a specific wavelength, the spectral image finally obtained will have higher clarity and accuracy. Since the deflection angle of the liquid crystal 1111 can be controlled by applying a voltage, the spectral characteristics of the filter unit 110 can be adjusted according to actual needs. This flexibility enables the spectral imaging device to adapt to different spectral imaging requirements.

[0043] In one embodiment, the liquid crystal portion 111 includes an ultrafast ferroelectric liquid crystal. As such, the ultrafast ferroelectric liquid crystal is known for its sub-microsecond response speed, which means that when a voltage is applied, the rearrangement and deflection of the liquid crystal 1111 is almost instantaneous, thus greatly reducing the time required for the spectral imaging device to scan the band. In addition, the ultrafast ferroelectric liquid crystal allows the spectral imaging device to capture images at a higher frame rate, thereby providing smoother and more accurate dynamic spectral data. The ultrafast ferroelectric liquid crystal has excellent contrast performance and can achieve a clear transition between the bright state and the dark state. This enables the imaging device to provide a clearer and easier to distinguish image when displaying spectral data. Due to the in-plane motion characteristics of the ultrafast ferroelectric liquid crystal, its viewing angle range is wider than that of conventional liquid crystal 1111. This means that no matter from which angle the observer views the imaging device, consistent and accurate image quality can be obtained. The bistable characteristics of the ultrafast ferroelectric liquid crystal enable it to maintain low power consumption when displaying static images. When the image remains unchanged, the liquid crystal 1111 molecules will remain in the current state, and no continuous power supply is required to maintain the display. This feature makes the spectral imaging device more energy-efficient in long-term operation or portable applications. Ultrafast ferroelectric liquid crystals generally have good high temperature stability and can maintain stable performance over a wide temperature range. This allows spectral imaging devices to operate reliably under a variety of environmental conditions without worrying about the impact of temperature on performance.

[0044] It should be noted that in the embodiments of the present application, the spectral imaging device using ultrafast ferroelectric liquid crystals can complete the scanning of 1200 bands in only 0.36 seconds, which is about one-hundredth of that of ordinary liquid crystals, greatly improving the efficiency of spectral imaging.

[0045] In one embodiment, among at least two filtering units 110, each filtering unit 110 is adapted to pass an optical signal with a wavelength within a preset range. Among them, the preset range wavelengths of at least two filtering units 110 have an intersection range, and the intersection range is: a ≤ λ ≤ b, where λ represents the wavelength, and a and b are constants, and 0nm < b - a ≤ 1nm. In this way, the intersection range is very narrow, which allows for a fine analysis of the optical signal. Although the preset range wavelengths of each filtering unit 110 have an intersection, overall they can cover a relatively wide spectral range. This design ensures that the imaging device can capture and analyze a wider range of spectral information, rather than just a narrow band. The design of the intersection range causes the optical signals between adjacent filtering units 110 to overlap, which helps to improve the continuity and stability of the signals, thereby improving the signal-to-noise ratio to a certain extent. In signal processing, this helps to reduce the influence of noise on spectral data. Since it is able to capture and analyze finer spectral information, this design helps to improve the imaging quality.

[0046] It should be noted that the number of filtering units 110 can be set to 2, 3, 4, 5, 6, 7, 8 or more. Specifically, the present application does not limit this. Taking the case where there are 8 filtering units 110 as an example, for instance, the first of the 8 filtering units 110 is adapted to pass an optical signal with a preset range wavelength of 555nm - 565nm, the second is adapted to pass an optical signal with a preset range wavelength of 556nm - 566nm, the third is adapted to pass an optical signal with a preset range wavelength of 557nm - 567nm, the fourth is adapted to pass an optical signal with a preset range wavelength of 558nm - 568nm, the fifth is adapted to pass an optical signal with a preset range wavelength of 559nm - 569nm, the sixth is adapted to pass an optical signal with a preset range wavelength of 560nm - 570nm, the seventh is adapted to pass an optical signal with a preset range wavelength of 561nm - 571nm, and the eighth is adapted to pass an optical signal with a preset range wavelength of 564nm - 574nm. In this way, the preset range wavelengths of the eight filtering units 110 have an intersection range of 564nm - 655nm. Of course, in other embodiments, the preset range wavelength that each filtering unit 110 is adapted to pass can be selected as needed, and the present application does not limit this.

[0047] In the field of optics, the duty cycle of a grating refers to the ratio between the transparent area and the opaque area in the grating. In the process of making the grating, different grating duty cycles can be obtained by setting the width and spacing of the transparent area and the opaque area. In practical applications, the size of the grating duty cycle will affect the distribution and transmission performance of the light intensity. In one embodiment, the duty cycle of the first grating portion 112 is B1, where 0.3≤B1≤0.7, so that the duty cycle is one of the key factors affecting the diffraction efficiency of the grating portion. In the range of 0.3 to 0.7, the first grating portion 112 can usually achieve a higher diffraction efficiency, which means that more light signals can be effectively guided to the subsequent filter unit 110, thereby improving the sensitivity and signal-to-noise ratio of spectral imaging. Appropriate duty cycle design helps to reduce the stray light generated by the first grating portion 112. The stray light is generated due to the imperfection of the structure of the first grating portion 112 or the interaction between the grating and the surrounding environment, which may interfere with the detection of the target spectral signal. In the duty cycle range of 0.3 to 0.7, the structural design of the first grating portion 112 can usually better balance the diffraction efficiency and stray light suppression, thereby achieving a purer spectral signal output. The design of the first grating portion 112 with a duty cycle in the range of 0.3 to 0.7 usually has good process compatibility. This means that in the production process, standard micro-nano processing technology can be used to manufacture this first grating portion 112, such as lithography, electron beam exposure, nanoimprinting, etc. These technologies are relatively mature and have high production efficiency and yield, thereby reducing the cost of the spectral imaging device. In the duty cycle range of 0.3 to 0.7, the performance of the first grating portion 112 is usually relatively stable. This means that under different environmental conditions (such as temperature, humidity, mechanical vibration, etc.), the performance of the first grating portion 112 changes little, thereby ensuring the stability and reliability of the spectral imaging device.

[0048] It should be noted that the duty cycle of the first grating portion 112 can be adjusted within the range of 0.3 to 0.7 as needed to optimize the performance of the spectral imaging device. For example, if a higher diffraction efficiency is required, the duty cycle can be appropriately increased; if a stronger stray light suppression capability is required, the duty cycle can be appropriately reduced. More specifically, the duty cycle of the first grating portion 112 can be 0.3, 0.45, 0.52, 0.6, 0.65 or 0.7, etc., and specifically, this application does not limit this.

[0049] The duty cycle of the second grating portion 113 is B2, where 0.3≤B2≤0.7. Thus, within the range of 0.3 to 0.7, the second grating portion 113 can generally achieve a higher diffraction efficiency, which means that more light signals can be effectively guided to the subsequent filter unit 110, thereby improving the sensitivity and signal-to-noise ratio of spectral imaging. Appropriate duty cycle design helps to reduce the stray light generated by the second grating portion 113. The stray light is generated due to the imperfection of the structure of the second grating portion 113 or the interaction between the grating and the surrounding environment, which may interfere with the detection of the target spectral signal. Within the duty cycle range of 0.3 to 0.7, the structural design of the second grating portion 113 can generally better balance the diffraction efficiency and stray light suppression, thereby achieving a purer spectral signal output. The design of the second grating portion 113 with a duty cycle in the range of 0.3 to 0.7 generally has better process compatibility. This means that in the production process, standard micro-nano processing technology can be used to manufacture this second grating portion 113, such as photolithography, electron beam exposure, nanoimprinting, etc. These technologies are relatively mature and have high production efficiency and yield, thereby reducing the cost of the spectral imaging device. In the duty cycle range of 0.3 to 0.7, the performance of the second grating portion 113 is usually relatively stable. This means that under different environmental conditions (such as temperature, humidity, mechanical vibration, etc.), the performance of the second grating portion 113 changes less, thereby ensuring the stability and reliability of the spectral imaging device.

[0050] It should be noted that the duty cycle of the second grating portion 113 can be adjusted within the range of 0.3 to 0.7 as needed to optimize the performance of the spectral imaging device. For example, if a higher diffraction efficiency is required, the duty cycle can be appropriately increased; if a stronger stray light suppression capability is required, the duty cycle can be appropriately reduced. More specifically, the duty cycle of the second grating portion 113 can be 0.3, 0.45, 0.52, 0.6, 0.65 or 0.7, etc., and specifically, this application does not limit this.

[0051] In addition, in the above embodiment, the duty cycle of the first grating portion 112 is B1 and the duty cycle of the second grating portion 113 is B2, and one of them can be selected to meet the above range. Of course, when the duty cycle of the first grating portion 112 is B1 and the duty cycle of the second grating portion 113 is B2, the above range is satisfied at the same time. In this way, the diffraction and filtering characteristics of the first grating portion 112 and the second grating portion 113 to the light signal are relatively balanced. This helps to maintain the continuity and consistency of the spectral data and improve the accuracy and reliability of spectral imaging. By setting a similar duty cycle, the two grating portions can distribute and transmit light signals more effectively. This helps to reduce the loss and distortion of the light signal, thereby improving the sensitivity and resolution of spectral imaging. Using a similar duty cycle can reduce the complexity of the design and manufacturing process. Because the first grating portion 112 and the second grating portion 113 have similar characteristics, they can be manufactured using the same processing technology and materials, thereby simplifying the production process and reducing costs. As before, the duty cycle range of 0.3 to 0.7 has good process compatibility. This means that the first grating section 112 and the second grating section 113 can be manufactured using standard micro-nano processing technology to ensure that they have consistent performance and reliability. Since the first grating section 112 and the second grating section 113 have similar duty cycles and characteristics, their responses to external factors such as ambient temperature and humidity are also similar. This helps to reduce performance fluctuations of the system caused by environmental changes and improve the stability and reliability of the spectral imaging device.

[0052] In the field of optics, the period of a grating refers to the distance between two adjacent identical structures on the grating. This period determines the basic properties of the grating, including diffraction, interference, and spectral resolution of light. In one embodiment, the period of the first grating portion 112 is T1, where 0.1um≤T1≤0.2um, so that the period of the first grating portion 112 determines its spectral resolution. In this specific period range, the first grating portion 112 can provide more refined spectral analysis, because a shorter period means that the first grating portion 112 can distinguish closer wavelengths. The period of the first grating portion 112 also affects its diffraction efficiency. In this period range, the first grating portion 112 can generally achieve a higher diffraction efficiency, which means that more light signals can be effectively guided to the subsequent filtering unit 110, thereby improving the sensitivity and signal-to-noise ratio of spectral imaging. Appropriate grating period design helps to reduce stray light. Stray light is generated due to the imperfection of the structure of the first grating portion 112 or the interaction between the grating and the surrounding environment, which may interfere with the detection of the target spectral signal. In the period range of 0.1um to 0.2um, the structural design of the first grating portion 112 can usually better balance the diffraction efficiency and stray light suppression. This period range matches the capabilities of current micro-nano processing technologies, such as photolithography and electron beam exposure. Therefore, using these technologies, a first grating portion 112 that meets these period requirements can be manufactured, ensuring the manufacturability and repeatability of the spectral imaging device. This period range provides a good balance between performance and cost. A shorter period can provide higher spectral resolution and diffraction efficiency, but it may also increase manufacturing costs. In the range of 0.1um to 0.2um, it is possible to control costs as much as possible while maintaining high performance. Appropriate grating period design helps to ensure the stability of the spectral imaging device. Since the period of the grating is closely related to parameters such as the diffraction angle and spectral resolution of the grating, selecting a suitable period as described above can ensure that the system can maintain stable performance under different environments and working conditions.

[0053] More specifically, the period of the first grating portion 112 may be 0.1um, 0.11um, 0.12um, 0.14um, 0.15um, 0.18um, 0.19um or 0.2um, etc. Specifically, the present application does not limit this.

[0054] In one embodiment, the period of the second grating portion 113 is T2, wherein 0.1um≤T2≤0.2um, and thus the period of the second grating portion 113 determines its spectral resolution. Within this particular period range, the second grating portion 113 can provide a finer spectral analysis, because a shorter period means that the second grating portion 113 can resolve closer wavelengths. The period of the second grating portion 113 also affects its diffraction efficiency. Within this period range, the second grating portion 113 can generally achieve a higher diffraction efficiency, which means that more light signals can be effectively guided to the subsequent filter unit 110, thereby improving the sensitivity and signal-to-noise ratio of spectral imaging. Appropriate grating period design helps to reduce stray light. Stray light is generated due to the imperfection of the structure of the second grating portion 113 or the interaction between the grating and the surrounding environment, which may interfere with the detection of the target spectral signal. Within the period range of 0.1um to 0.2um, the structural design of the second grating portion 113 can generally better balance the diffraction efficiency and stray light suppression. This period range matches the capabilities of current micro-nano processing technologies, such as photolithography and electron beam exposure. Therefore, using these technologies, a second grating portion 113 that meets these period requirements can be manufactured, ensuring the manufacturability and repeatability of the spectral imaging device. This period range provides a good balance between performance and cost. A shorter period can provide higher spectral resolution and diffraction efficiency, but it may also increase manufacturing costs. Within the range of 0.1um to 0.2um, costs can be controlled as much as possible while maintaining high performance. Appropriate grating period design helps to ensure the stability of the spectral imaging device. Since the period of the grating is closely related to parameters such as the diffraction angle and spectral resolution of the grating, selecting a suitable period as mentioned above can ensure that the system can maintain stable performance under different environments and working conditions.

[0055] More specifically, the period of the second grating portion 113 may be 0.1um, 0.11um, 0.12um, 0.14um, 0.15um, 0.18um, 0.19um or 0.2um, etc. Specifically, the present application does not limit this.

[0056] In addition, in the above embodiment, the period of the first grating portion 112 is T1 and the period of the second grating portion 113 is T2, which can be selected to meet the above range. Of course, when the period of the first grating portion 112 is T1 and the period of the second grating portion 113 is T2, the above range is satisfied at the same time. In this way, since the periods of the first grating portion 112 and the second grating portion 113 are in the same range, their spectral resolution and diffraction effect will be consistent and comparable. This helps to ensure that the data generated by different parts in the entire spectral imaging system have a high degree of coherence and interpretability. Within this period range, the grating can provide fine spectral resolution, whether in the first grating portion 112 or the second grating portion 113, it can effectively distinguish small wavelength changes. In the period range of 0.1um to 0.2um, the first grating portion 112 and the second grating portion 113 can usually achieve a higher diffraction efficiency. This means that more light signals can be effectively guided to the subsequent filter unit 110, thereby improving the sensitivity and signal-to-noise ratio of spectral imaging. Since this period range matches the capabilities of current micro-nano processing technology, the first grating section 112 and the second grating section 113 can be manufactured using the same processing technology and materials. This simplifies the manufacturing process, reduces costs, and ensures that the first grating section 112 and the second grating section 113 have consistent performance. Since the first grating section 112 and the second grating section 113 have the same period, their responses to external factors such as ambient temperature and humidity are also similar. This helps to reduce performance fluctuations of the system due to environmental changes and improve the stability and reliability of the spectral imaging device.

[0057] Reference Figures 3 to 6 In one embodiment, the first grating portion 112 includes a first substrate 1121 and a plurality of first metal grating strips 1122, the plurality of first metal grating strips 1122 are arranged on the first end surface of the first substrate 1121, the plurality of first metal grating strips 1122 are arranged at equal intervals, and each first metal grating strip 1122 is extended along the second direction, so that the first metal grating strips 1122 arranged at equal intervals can ensure that the light signal is uniformly diffracted or reflected, thereby achieving accurate spectral separation. This uniform spacing helps to maintain the continuity and consistency of the spectrum and improve the accuracy of spectral imaging. Metal grating strips usually have a high diffraction efficiency, which means that more light signals can be effectively guided to the subsequent filter unit 110. High diffraction efficiency helps to improve the sensitivity and signal-to-noise ratio of spectral imaging. The metal grating strips have good mechanical stability and thermal stability, and can resist a certain degree of temperature changes and mechanical vibrations. This enables the first grating portion 112 to maintain stable performance under various environmental conditions. The first metal grating strips 1122 arranged at equal intervals can be manufactured using standard micro-nano processing techniques, such as photolithography, electron beam exposure, etc. These techniques can ensure that the grating portion has high precision and consistency.

[0058] It should be noted that the spectral resolution and diffraction characteristics of the grating portion can be flexibly adjusted by adjusting the parameters such as the width, interval and length of the first metal grating strips 1122. Specifically, the present application does not limit this.

[0059] Reference Figures 3 to 6 In one embodiment, the second grating portion 113 includes a second substrate 1131 and a plurality of second metal grating strips 1132, the plurality of second metal grating strips 1132 are arranged on the second end surface of the second substrate 1131, the plurality of second metal grating strips 1132 are arranged at equal intervals, and each second metal grating strip 1132 is extended along a third direction, the third direction is perpendicular to the first direction, and the third direction is also perpendicular to the second direction. Since the third direction is perpendicular to both the first direction and the second direction, this design provides the ability to separate spectral signals in another direction. This increases the dimension of spectral imaging, allowing the spectral imaging device to capture richer spectral information. The second metal grating strips 1132 arranged at equal intervals help to achieve more uniform spectral separation, thereby improving spectral resolution. This helps to more accurately identify and measure optical signals of different wavelengths or frequencies. Since the grating strips of the first grating portion 112 and the second grating portion 113 extend in different directions, the interference between them is greatly reduced. This helps to maintain the clarity and accuracy of the spectral signal.

[0060] It should be noted that, since the design of the second grating portion 113 is independent of the first grating portion 112, they can be more easily integrated into the same spectral imaging system. This integration makes the spectral imaging device more compact, efficient and easy to operate. The metal grating strips have excellent optical properties, including high reflectivity, low absorption rate and good diffraction characteristics, so that the first grating portion 112 and the second grating portion 113 can provide clear and accurate spectral imaging results. In addition, the spectral resolution and diffraction characteristics of the second grating portion 113 can be flexibly adjusted by adjusting the parameters such as the width, spacing and length of the second metal grating strips 1132. Specifically, this application is not limited to this.

[0061] In one embodiment, the thickness of the first substrate 1121 is H1, wherein 0.2um≤H1≤0.7um. Thus, the first substrate 1121 serves as the basic support structure of the plurality of first metal grating strips 1122, and its thickness directly affects the mechanical stability of the entire first grating portion 112. Within this range, the first substrate 1121 can maintain a high spectral resolution and provide sufficient mechanical strength to ensure that the first grating portion 112 remains stable under various working conditions. The thickness of the first substrate 1121 also has an important influence on the optical performance of the first grating portion 112. The first substrate 1121 of appropriate thickness can reduce the loss and scattering of the optical signal during transmission, thereby improving the sensitivity and resolution of spectral imaging. At the same time, it can also reduce the noise caused by material absorption and scattering, and improve the signal-to-noise ratio. During spectral imaging, the first grating portion 112 may be affected by temperature changes. The first substrate 1121 of appropriate thickness can provide better thermal stability to ensure that the grating portion can maintain stable performance when the temperature changes. This thickness range matches the capabilities of current micro-nano processing technology. While maintaining high mechanical stability and optical performance, this thickness range also takes cost factors into consideration. An overly thick first substrate 1121 may increase material cost and manufacturing cost, while an overly thin first substrate 1121 may increase processing difficulty and cost. Within this range, a good balance between performance and cost can be achieved.

[0062] More specifically, the thickness of the first substrate 1121 can be 0.2um, 0.25um, 0.3um, 0.33um, 0.38um, 0.42um, 0.43um, 0.5um, 0.54um, 0.56um, 0.59um, 0.6um, 0.61um, 0.63um, 0.66um, 0.68um, 0.69um or 0.7um, etc. Specifically, the present application does not limit this.

[0063] In one embodiment, the thickness of the second substrate 1131 is H2, wherein 0.2um≤H2≤0.7um. Thus, the second substrate 1131 serves as the basic support structure of the plurality of second metal grating strips 1132, and its thickness directly affects the mechanical stability of the entire second grating portion 113. Within this range, the second substrate 1131 can maintain a high spectral resolution and provide sufficient mechanical strength to ensure that the second grating portion 113 remains stable under various working conditions. The thickness of the second substrate 1131 also has an important influence on the optical performance of the second grating portion 113. A second substrate 1131 of appropriate thickness can reduce the loss and scattering of optical signals during transmission, thereby improving the sensitivity and resolution of spectral imaging. At the same time, it can also reduce the noise caused by material absorption and scattering, and improve the signal-to-noise ratio. During spectral imaging, the second grating portion 113 may be affected by temperature changes. A second substrate 1131 of appropriate thickness can provide better thermal stability to ensure that the grating portion can maintain stable performance when the temperature changes. This thickness range matches the capabilities of current micro-nano processing technology. While maintaining high mechanical stability and optical performance, this thickness range also takes cost factors into consideration. A second substrate 1131 that is too thick may increase material cost and manufacturing cost, while a second substrate 1131 that is too thin may increase processing difficulty and cost. Within this range, a good balance between performance and cost can be achieved.

[0064] More specifically, the thickness of the second substrate 1131 can be 0.2um, 0.21um, 0.15um, 0.34um, 0.38um, 0.43um, 0.46um, 0.51um, 0.54um, 0.56um, 0.59um, 0.6um, 0.62um, 0.63um, 0.66um, 0.68um, 0.69um or 0.7um, etc. Specifically, the present application does not limit this.

[0065] In one embodiment, the thickness of the first metal grating strip 1122 is H3, wherein 0.05um≤H3≤0.3um, and thus the thickness of the first metal grating strip 1122 directly affects its optical properties, such as transmittance, reflectivity, and diffraction efficiency. Within this thickness range, the first metal grating strip 1122 can provide relatively ideal optical properties, such as higher diffraction efficiency, to ensure that the first metal grating strip 1122 can achieve higher resolution and sensitivity in spectral analysis and imaging applications. Within this thickness range, the first metal grating strip 1122 can reduce light scattering and unnecessary interference, thereby improving the accuracy and reliability of spectral data.

[0066] More specifically, the thickness of the first metal grating strip 1122 can be 0.05um, 0.06um, 0.08um, 0.09um, 0.1um, 0.12um, 0.13um, 0.14um, 0.15um, 0.16um, 0.19um, 0.2um, 0.22um, 0.23um, 0.24um, 0.25um, 0.26um, 0.27um or 0.3um, etc. Specifically, this application does not limit this.

[0067] In one embodiment, the thickness of the second metal grating strip 1132 is H4, wherein 0.05um≤H4≤0.3um. Thus, the thickness of the second metal grating strip 1132 directly affects its optical properties, such as transmittance, reflectivity, and diffraction efficiency. Within this thickness range, the second metal grating strip 1132 can provide relatively ideal optical properties, such as higher diffraction efficiency, to ensure that the second metal grating strip 1132 can achieve higher resolution and sensitivity in spectral analysis and imaging applications. Within this thickness range, the second metal grating strip 1132 can reduce light scattering and unnecessary interference, thereby improving the accuracy and reliability of spectral data.

[0068] More specifically, the thickness of the second metal grating strip 1132 can be 0.05um, 0.06um, 0.08um, 0.09um, 0.1um, 0.12um, 0.13um, 0.14um, 0.15um, 0.16um, 0.19um, 0.2um, 0.22um, 0.23um, 0.24um, 0.25um, 0.26um, 0.27um or 0.3um, etc. Specifically, this application does not limit this.

[0069] Reference Figure 1In one embodiment, in two adjacent filter units 110, the first grating portion 112 of one filter unit 110 is attached to the first grating portion 112 of the other filter unit 110, and along the first direction, the orthographic projections of the first metal grating strips 1122 of the two attached first grating portions 112 at least partially overlap. In this way, since the first grating portions 112 of the adjacent filter units 110 are closely attached, and the orthographic projections of the metal grating strips at least partially overlap, it is ensured that the optical signal can maintain a high spectral continuity when passing through the filter. This is crucial for applications requiring high-resolution spectral analysis because it helps to reduce the loss or distortion of spectral information. Since the orthographic projections of the metal grating strips partially overlap, this design allows the optical signal to be subjected to more consistent diffraction when passing through two adjacent first grating portions 112. This helps to improve the resolution of the spectrum, so that the filter unit 110 can more accurately distinguish optical signals of different wavelengths or frequencies. The attached design reduces the loss of optical signals during propagation. Since the two adjacent first grating parts 112 are closely fitted, the optical signal can be transmitted more smoothly from one filter unit 110 to another filter unit 110, reducing the loss of optical signals caused by interface reflection or scattering. The adjacent filter units 110 form a more stable overall structure through the bonding of the two adjacent first grating parts 112. This structure can resist external vibration or impact and maintain the stability and reliability of the spectroscopic structure 100. Since the two adjacent first grating parts 112 are directly bonded, no additional fixing or connecting elements are required, which simplifies the assembly process of the spectroscopic structure 100. This not only reduces production costs, but also improves production efficiency. This design makes the spectroscopic structure 100 easier to expand or combine. By increasing the number and configuration of the filter units 110, it can meet the needs of different spectral ranges and resolutions. This is very important for meeting the needs of different application scenarios.

[0070] Reference Figure 2 In one embodiment, in two adjacent filter units 110 , the first grating portion 112 of one filter unit 110 is attached to the second grating portion 112 of the other filter unit 110 . Specifically, the present application does not limit this.

[0071] Reference Figure 3 and Figure 6In one embodiment, the liquid crystal portion 111 includes a main body 1112, a liquid crystal unit 1113 and a conductive portion. The main body 1112 is sandwiched between the first grating portion 112 and the second grating portion 113. The main body 1112 forms a receiving space, and the liquid crystal unit 1113 is arranged in the receiving space. The liquid crystal unit 1113 includes a plurality of liquid crystals 1111. The conductive portion is arranged on the main body 1112. The conductive portion includes a positive electrode column 1114 and a negative electrode column 1115. The positive electrode column 1114 and the negative electrode column 1115 are electrically connected to the liquid crystal unit 1113. In this way, the first grating portion 112 and the second grating portion 113 can accurately control the wavelength and angle of light entering the liquid crystal unit 1113, thereby effectively filtering out unnecessary stray light and improving the clarity and contrast of imaging. The plurality of liquid crystals 1111 in the liquid crystal unit 1113 can be precisely controlled by applying voltage to the positive electrode column 1114 and the negative electrode column 1115 of the conductive portion. This control can ensure that the liquid crystal 1111 deflects at a predetermined angle, thereby achieving precise modulation of the incident light. Due to the direct connection between the conductive portion and the liquid crystal unit 1113, the voltage applied to the liquid crystal 1111 can respond quickly, achieving rapid adjustment of the deflection angle of the liquid crystal 1111. By changing the voltage applied to the liquid crystal 1111, the deflection angle of the liquid crystal 1111 can be continuously adjusted, thereby achieving flexible control of light of different wavelengths.

[0072] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A spectral imaging device, characterized in that: include: A light splitting structure, comprising at least two filter units, wherein the at least two filter units are stacked in sequence along a first direction, each of the filter units comprises a liquid crystal portion, a first grating portion and a second grating portion, wherein the liquid crystal portion is suitable for being applied with a voltage, and along the first direction, the first grating portion and the second grating portion are respectively located on two opposite sides of the liquid crystal portion and are both in contact with the side surfaces corresponding to the liquid crystal portion; The photosensitive unit is arranged relative to the light splitting structure, and is used to obtain the light signal filtered by the light splitting structure and is suitable for converting the light signal into an electrical signal.

2. The spectral imaging device according to claim 1, characterized in that: When voltage is applied to the liquid crystal parts of the at least two filter units, the deflection angles of the liquid crystals of the at least two liquid crystal parts are different, so that part of the light signal filtered out by one of the filter units is suitable to be filtered out by the other filter unit.

3. The spectral imaging device according to claim 1, characterized in that: The liquid crystal portion includes ultrafast ferroelectric liquid crystal.

4. The spectral imaging device according to claim 1, characterized in that: Each of the at least two filter units is suitable for passing an optical signal with a preset range of wavelengths, wherein the preset ranges of wavelengths of the at least two filter units have an intersection range, and the intersection range is: a≤λ≤b, wherein λ represents the wavelength, a and b are constants, and 0nm <b-a≤1nm。 5. The spectral imaging device according to claim 1, characterized in that: The duty cycle of the first grating portion is B1, wherein 0.3≤B1≤0.7; and / or, The duty cycle of the second grating portion is B2, wherein 0.3≤B2≤0.

7.

6. The spectral imaging device according to claim 1, characterized in that: The period of the first grating portion is T1, wherein 0.1um≤T1≤0.2um; and / or, The period of the second grating portion is T2, wherein 0.1um≤T2≤0.2um.

7. The spectral imaging device according to any one of claims 1 to 6, characterized in that: The first grating portion includes a first substrate and a plurality of first metal grating strips, the plurality of first metal grating strips are arranged on a first end surface of the first substrate, the plurality of first metal grating strips are arranged at equal intervals, and each of the first metal grating strips is extended along the second direction; and, The second grating portion includes a second substrate and a plurality of second metal grating strips, wherein the plurality of second metal grating strips are arranged on the second end surface of the second substrate, the plurality of second metal grating strips are arranged at equal intervals, and each of the second metal grating strips extends along a third direction, wherein the third direction is perpendicular to the first direction, and the third direction is also perpendicular to the second direction.

8. The spectral imaging device according to claim 7, characterized in that: The thickness of the first substrate is H1, wherein 0.2um≤H1≤0.7um; and / or, The thickness of the second substrate is H2, wherein 0.2um≤H2≤0.7um.

9. The spectral imaging device according to claim 7, characterized in that: The thickness of the first metal grating strip is H3, wherein 0.05um≤H3≤0.3um; and / or, The thickness of the second metal grating strip is H4, wherein 0.05um≤H4≤0.3um.

10. The spectral imaging device according to claim 7, characterized in that: In two adjacent filter units, the first grating portion of one filter unit is attached to the first grating portion of the other filter unit, and along the first direction, the orthographic projections of the first metal grating strips of the two attached first grating portions at least partially overlap.

Images