Photosensitive device, color detection method and metasurface filter chip

Abstract

This application discloses a photosensitive device, a color detection method, and a metasurface filter chip. The photosensitive device includes: a polarization adjustment component capable of converting light to be detected into linearly polarized light, and at least capable of controlling the polarization direction of the linearly polarized light to switch between a first polarization direction and a second polarization direction; a filter component disposed on the light-emitting side of the polarization adjustment component, including at least a first filter structure and a second filter structure; the first filter structure is used to perform multi-channel passband filtering of linearly polarized light in the first polarization direction within a first wavelength range, and to block linearly polarized light in the second polarization direction; the second filter structure is used to perform multi-channel passband filtering of linearly polarized light in the second polarization direction within a second wavelength range, and to block linearly polarized light in the first polarization direction; and a photosensitive chip disposed on the light-emitting side of the filter component; the photosensitive chip is used to sense the light signal output by the filter component, and the light signal can characterize multi-channel color data.

Description

Technical Field

[0001] This application relates to the field of color detection technology, and in particular to a photosensitive device, a color detection method, and a metasurface filter chip. Background Technology

[0002] Color is one of the most important visual and perceptual features of an object. However, existing technologies still have technical limitations in obtaining the true color information of an object, thus failing to achieve accurate color reproduction. Summary of the Invention

[0003] In view of the above problems, this application provides a photosensing device, a color detection method, and a metasurface filter chip to achieve the purpose of acquiring multi-channel color data. The specific solution is as follows: The first aspect of this application provides a photosensitive device, comprising: The polarization adjustment component can convert the light to be detected into linearly polarized light. The polarization adjustment component can at least control the polarization direction of the linearly polarized light to switch between a first polarization direction and a second polarization direction. A filter assembly is disposed on the light-emitting side of a polarization adjustment assembly. The filter assembly includes at least a first filter structure and a second filter structure. The first filter structure is used to perform multi-channel passband filtering of linearly polarized light in a first polarization direction within a first wavelength range and to block linearly polarized light in a second polarization direction. The second filter structure is used to perform multi-channel passband filtering of linearly polarized light in a second polarization direction within a second wavelength range and to block linearly polarized light in the first polarization direction. The first wavelength range and the second wavelength range do not overlap and cover the target wavelength range. A photosensitive chip is located on the light-emitting side of the filter assembly; the photosensitive chip is used to sense the light signal output by the filter assembly, and the light signal can represent multi-channel color data.

[0004] Optionally, in the above-mentioned photosensitive device, the first filter structure includes an array of multiple first metasurface filter units with different structural parameters; The second filter structure comprises an array of multiple second metasurface filter units with different structural parameters; Each metasurface filter unit corresponds to a different target channel transmission peak wavelength.

[0005] Optionally, the above-mentioned photosensitive device further includes a control module, which is configured to: When the polarization adjustment component is in the first state, the first wavelength channel signal acquired by the photosensitive chip is obtained. When the polarization adjustment component is in the second state, the second wavelength channel signal acquired by the photosensitive chip is obtained; The first wavelength channel signal and the second wavelength channel signal are then fused to generate multi-channel color data. The polarization adjustment component emits linearly polarized light in a first polarization direction in the first state and linearly polarized light in a second polarization direction in the second state.

[0006] Optionally, in the above-mentioned photosensitive device, the filter component includes a light-transmitting substrate; The first filter structure and the second filter structure are disposed on the side surface of the light-transmitting substrate facing the polarization adjustment component. The surface includes a first region opposite to the first filter structure and a second region opposite to the second filter structure. The first region and the second region do not overlap.

[0007] Optionally, in the above-mentioned photosensitive device, the filter component includes: A first optical modulation layer covers a first region and exposes a second region; A light-transmitting dielectric layer covers the first light modulation layer and the second region; A metasurface pattern structure located on the surface of the light-transmitting medium layer facing away from the light-transmitting substrate, the metasurface pattern structure includes: an array of multiple first metasurface filter units opposite to a first region; an array of multiple second metasurface filter units opposite to a second region; each first metasurface filter unit and each second metasurface filter unit corresponds to a channel.

[0008] Optionally, in the above-mentioned photosensitive device, the first metasurface filter unit includes a plurality of parallel gratings, the length direction of which is parallel to the second polarization direction; Each of the first metasurface filter units has the same grating thickness and the same grating period; Each of the first metasurface filter units has a different linewidth of grating, which is matched with the target channel transmission peak wavelength of the corresponding channel of the first metasurface filter unit.

[0009] Optionally, in the above-mentioned photosensitive device, the filter component includes a patterned second light modulation layer disposed on the light-transmitting medium layer, the second light modulation layer having a metasurface patterned structure; the second metasurface filter unit is a hollow pattern penetrating the second light modulation layer; The cutout pattern corresponding to the second metasurface filter unit includes two arc-shaped slits that are symmetrical about an axis parallel to the second polarization direction, with the two arc-shaped slits curving in opposite directions.

[0010] Optionally, in the above-mentioned photosensitive device, the two arc-shaped slits corresponding to different second metasurface filter units have the same spacing and the same slit width; The outer diameter of the arc-shaped slit in different second metasurface filter units is different, and the outer diameter matches the target channel transmission peak wavelength of the corresponding channel of the second metasurface filter unit.

[0011] A second aspect of this application provides a color detection method, comprising: The light to be detected is converted into linearly polarized light through a polarization adjustment component, and the polarization direction of the linearly polarized light is controlled to switch between a first polarization direction and a second polarization direction. When the light emitted from the polarization adjustment component is in the first polarization direction, it is incident on the first filter structure in the first region of the filter component to obtain optical signals of multiple first wavelength channels; when the light is in the second polarization direction, it is incident on the second filter structure in the second region of the filter component to obtain optical signals of multiple second wavelength channels; wherein, the first region and the second region are different, and the wavelength ranges of the multiple first wavelength channels and the multiple second wavelength channels do not overlap; A photosensitive chip is used to sense the light signals of the first wavelength channel and the second wavelength channel respectively to obtain multi-channel color data.

[0012] A third aspect of this application provides a metasurface filter chip, comprising: Transparent substrate; A first filter structure and a second filter structure are disposed on a light-transmitting substrate; The first filter structure includes multiple first metasurface filter units. Each first metasurface filter unit includes a first light modulation layer, a light-transmitting medium layer, and a second light modulation layer arranged sequentially. The first metasurface filter unit includes multiple parallel strip-shaped metal structures. The first metasurface filter unit is configured to selectively transmit incident light with a first polarization direction. The second filter structure includes multiple second metasurface filter units, each of which includes a pair of C-shaped metal structure slots disposed on the light-transmitting medium layer. The pair of C-shaped metal structure slots are configured to form a coupled resonance and perform wavelength-selective transmission of incident light with a second polarization direction. The first polarization direction is orthogonal to the second polarization direction, and the first metasurface filter unit and the second metasurface filter unit correspond to different wavelength ranges.

[0013] Optionally, in the above-mentioned metasurface filter chip, In the first filter structure, different first metasurface filter units have different strip-shaped metal structure widths to form multiple first filter channels with different center wavelengths; In the second filter structure, different second metasurface filter units have different paired C-shaped metal structure gap sizes to form multiple second filter channels with different center wavelengths. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0015] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0016] Figure 1 This is a schematic diagram of the structure of a photosensitive device provided in an embodiment of this application; Figure 2 This is a schematic diagram illustrating the layout principle of a filter structure in a filter assembly, as provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a photosensitive device provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a polarization adjustment component provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a filter assembly provided in an embodiment of this application; Figure 6 This is a schematic diagram of another filter component provided in an embodiment of this application; Figure 7 A top view of a filter assembly provided in an embodiment of this application in a local region corresponding to two adjacent first metasurface filter units; Figure 8 for Figure 7 A cross-sectional view of the filter assembly shown; Figure 9 A top view of a filter assembly provided in an embodiment of this application in a local region corresponding to two adjacent second metasurface filter units; Figure 10 for Figure 9 A cross-sectional view of the filter assembly shown; Figure 11 A three-dimensional structural schematic diagram of a filter component in a local region corresponding to a second metasurface filter unit, provided in an embodiment of this application; Figure 12 A spectral transmission curve of a filter component in the short-wavelength region along a first polarization direction, provided in an embodiment of this application; Figure 13 An electric field intensity distribution diagram of a vertical cross-section of a first metasurface filter unit provided in an embodiment of this application; Figure 14 The filtering characteristic curve of oblique incident light of a first metasurface filtering unit provided in the embodiments of this application; Figure 15 The spectral transmission curve of a filter component in the long-wavelength region along the second polarization direction is provided in the embodiment of the application. Figure 16 An electric field distribution diagram of a second metasurface filter unit provided in an embodiment of this application; Figure 17 A filtering characteristic curve of a second metasurface unit for obliquely incident light is provided in an embodiment of this application; Figure 18 A schematic flowchart of a color detection method provided in an embodiment of this application; Figure 19 This is the filtering curve of the photosensitive device's filter component in the visible light spectrum in the embodiments of this application.

[0017] The annotations in the attached figures are explained as follows: 100 Polarization adjustment component; 101 Filter component; 1011 First filter structure; 1012 Second filter structure; 102 Photosensitive chip; 1031 First metasurface filter unit; 1032 Second metasurface filter unit; 104 Control module; 105 Liquid crystal panel; 1051 First light-transmitting electrode; 1052 Second light-transmitting electrode; 1053 Liquid crystal layer; 106 Linear polarizer; 107 Light-transmitting substrate; 1071 First region; 1072 Second region; 108 First light modulation layer; 109 Light-transmitting medium layer; 110 Metasurface pattern structure; 111 Grating; 112 Second light modulation layer; 113 Hollowed-out pattern. Detailed Implementation

[0018] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0019] Typical color sensors have only 3–4 color channels (RGBW), resulting in limited accuracy and extreme reliance on precise photomasks and white balance. RGB sensors, in essence, transmit a continuous spectrum. The value is compressed into 3-4 integral values. Taking red light as an example, the output response value of the red light channel can be expressed as follows: .

[0020] In the above formula, This represents the spectral response function of the sensor in the red light channel, i.e., the sensitivity curves of this channel at different wavelengths.

[0021] According to the principle of metamerism, many objects with completely different spectral distributions (such as a certain retro green and a mixed green) may have identical R, G, and B response values ​​when integrated under a broadband RGB filter. Therefore, calculating the true spectral reflectance of an object or the spectral distribution of a light source using only 3-4 channels is mathematically an "underdetermined problem" and cannot be solved accurately. High-precision color sensors typically provide more than 10 narrowband spectral channels (multispectral sensors), and even achieve a qualitative leap in recognition accuracy by acquiring continuous spectral distribution curves instead of simple RGB three primary colors. However, accurately acquiring continuous spectral distribution curves usually requires the use of a spectrometer, which results in large device size, high power consumption, poor integration, and high cost.

[0022] Therefore, using ordinary commercial CMOS sensors (400nm-780nm) as photosensitive chips and applying precise light filtering to the surface of the photosensitive chip to achieve low-cost and ultra-compact spectral sensing and detection, and to use them in small-sized color sensing devices, such as portable color pens, mobile phones, and cameras, is an urgent industrial need.

[0023] In view of this, embodiments of this application provide a photosensing device, including: The polarization adjustment component can convert the light to be detected into linearly polarized light. The polarization adjustment component can at least control the polarization direction of the linearly polarized light to switch between a first polarization direction and a second polarization direction. A filter assembly is disposed on the light-emitting side of a polarization adjustment assembly. The filter assembly includes at least a first filter structure and a second filter structure. The first filter structure is used to perform multi-channel passband filtering of linearly polarized light in a first polarization direction within a first wavelength range and to block linearly polarized light in a second polarization direction. The second filter structure is used to perform multi-channel passband filtering of linearly polarized light in a second polarization direction within a second wavelength range and to block linearly polarized light in the first polarization direction. The first wavelength range and the second wavelength range do not overlap and cover the target wavelength range. A photosensitive chip is located on the light-emitting side of the filter assembly; the photosensitive chip is used to sense the light signal output by the filter assembly, and the light signal can represent multi-channel color data.

[0024] The photosensitive device provided in this application embodiment includes a polarization adjustment component. This component can convert the light to be detected into linearly polarized light and switch the polarization direction of the linearly polarized light between a first polarization direction and a second polarization direction. The filter component in the photosensitive device has a first filter structure and a second filter structure that match different polarization directions. The first filter structure and the second filter structure can selectively transmit linearly polarized light of the corresponding polarization direction to achieve multi-channel passband filtering. This allows the photosensitive chip to sense the light signal representing multi-channel color data output by the filter component and acquire the spectrum of the multi-channel color data.

[0025] Optionally, both the first and second filter structures can be metasurface filter unit arrays, making the filter component a metasurface filter. In this case, the filter component achieves passband filtering in the first and second wavelength ranges based on the first and second filter structures, respectively, solving the problem of insufficient response band range of conventional metasurface filters. Since both filter structures can achieve multi-channel bandpass filtering within their respective wavelength ranges, the photosensitive chip can acquire multi-channel spectral data, and the reconstructed color data based on this is more accurate than the conventional RGB three-channel scheme.

[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments described in this application are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The terminology used in the embodiments of this application is only used to explain the specific embodiments of this application and is not intended to limit this application.

[0027] refer to Figure 1 , Figure 1 This is a schematic diagram of a photosensitive device provided in an embodiment of the present application. The photosensitive device includes a polarization adjustment component 100, a filter component 101, and a photosensitive chip 102 arranged in sequence. Figure 1 The middle arrow indicates the direction of propagation of the light ray to be detected. Figure 1 This is a schematic diagram of the stacked structure of the polarization adjustment component 100, the filter component 101, and the photosensitive chip 102 in this direction in the photosensitive device.

[0028] The polarization adjustment component 100 can convert the light to be detected into linearly polarized light, and the polarization adjustment component 100 can at least control the polarization direction of the linearly polarized light to switch between a first polarization direction and a second polarization direction.

[0029] The filter assembly 101 is disposed on the light-emitting side of the polarization adjustment assembly 100; the filter assembly 101 includes at least a first filter structure 1011 and a second filter structure 1012; the first filter structure 1011 is used to perform multi-channel passband filtering of linearly polarized light in the first polarization direction within a first wavelength range, and to block linearly polarized light in the second polarization direction; the second filter structure 1012 is used to perform multi-channel passband filtering of linearly polarized light in the second polarization direction within a second wavelength range, and to block linearly polarized light in the first polarization direction; wherein the first wavelength range and the second wavelength range do not overlap, and both cover the target wavelength range.

[0030] Optionally, the target wavelength range includes the visible light band, and the first wavelength range and the second wavelength range can be different wavelength bands within the visible light band. For example, if the visible light band is 400nm~780nm, the first wavelength range can be 400nm~600nm, and the second wavelength range can be 600nm~780nm. 600nm can belong to the second wavelength range but not to the first wavelength range.

[0031] The photosensitive chip 102 is disposed on the light-emitting side of the filter assembly 101; the photosensitive chip 102 is used to sense the light signal output by the filter assembly 101, and the light signal can characterize multi-channel color data.

[0032] Optionally, the photosensitive chip 102 is a monochrome CMOS sensor. The photosensitive chip 102 performs passband filtering through the filter assembly 101, eliminating the need for a conventional Bayer filter array and thus avoiding the absorption and blocking of light by the Bayer filter array, effectively improving photosensitivity. In this embodiment, the photosensitive device can be used not only as a color sensing device, but also, based on the monochrome CMOS sensor, to directly acquire the monochrome texture pattern of an object.

[0033] In this embodiment, the polarization adjustment component 100, the filter component 101, and the photosensitive chip 102 are of the same or approximately the same size. The photosensitive chip 102, with its defined size, can be used as a carrier, and the filter component 101 and the polarization adjustment component 100 can be sequentially stacked and fixed on it, thereby achieving integrated integration of various structural components in the photosensitive device and improving integration density. For example, if the photosensitive chip 102 is a monochrome CMOS sensor, the filter component 101 and the polarization adjustment component 100 can be of the same or approximately the same size as the monochrome CMOS sensor, facilitating integrated packaging and integration of different structural components in the photosensitive device.

[0034] refer to Figure 2 , Figure 2 This is a schematic diagram illustrating the layout principle of a filter structure in a filter assembly, provided in an embodiment of this application. Figure 2 This is a top view of the filter structure on the plane where the filter assembly 101 is located. Figure 2The diagram only provides a simplified illustration of the array arrangement of the metasurface filter units in the two filter structures, and does not show the specific graphical structures of the first metasurface filter unit 1031 and the second metasurface filter unit 1032. The first filter structure 1011 includes an array of multiple first metasurface filter units 1031 with different structural parameters; the second filter structure 1012 includes an array of multiple second metasurface filter units 1032 with different structural parameters; wherein each metasurface filter unit corresponds to a different target channel transmission peak wavelength.

[0035] like Figure 2 As shown, the filter component 101 provided in this application embodiment can form metasurface filter units related to the peak transmission wavelength of the target channel in the regions where the first filter structure 1011 and the second filter structure 1012 are located, respectively. The structural parameters of each metasurface filter unit are matched with the peak transmission wavelength of its corresponding target channel. The peak transmission wavelength of the target channel can be changed by adjusting the structural parameters of the metasurface filter unit. When used for visible light detection, this application embodiment can acquire color information in a multi-channel manner covering the visible light range, that is, it can reconstruct more accurate color data, and the number of channels can be flexibly increased or decreased according to application requirements.

[0036] Alternatively, in one implementation, such as Figure 2 As shown, the first filter structure 1011 has a first metasurface filter unit 1031 arranged in a 3×4 array, and the second filter structure 1012 has a second metasurface filter unit 1032 arranged in a 3×4 array.

[0037] It should be noted that the number and array arrangement of the metasurface filter units in the first filter structure 1011 and the second filter structure 1012 can be the same or different. The number and array arrangement of the first metasurface filter units 1031 in the first filter structure 1011 can be configured and are not limited to a 3×4 array arrangement; they can also be a 3×3 array arrangement, a 5×6 array arrangement, or other multi-channel array arrangements. Similarly, the number and array arrangement of the second metasurface filter units 1032 in the second filter structure 1012 can be configured and are not limited to a 3×4 array arrangement; they can also be a 3×3 array arrangement, a 5×6 array arrangement, or other multi-channel array arrangements.

[0038] In this embodiment, both the first filter structure 1011 and the second filter structure 1012 can achieve compatibility with incident light at an oblique angle by adjusting the graphic structure and size parameters of their respective metasurface filter units. When the incident light is obliquely incident, the offset of the peak wavelength in the transmission light wave curve of the two filter structures is reduced, so that the photosensitive device can still maintain a stable channel response and color recognition capability under non-perpendicular incident conditions, effectively alleviating the spectral distortion and color distortion caused by large-angle oblique incident light.

[0039] refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a photosensitive device provided in an embodiment of this application. Based on other embodiments, Figure 3 The photosensitive device also includes a control module 104, which is electrically connected to the photosensitive chip 102. The control module 104 is configured to: acquire a first wavelength channel signal collected by the photosensitive chip 102 when the polarization adjustment component 100 is in a first state; acquire a second wavelength channel signal collected by the photosensitive chip 102 when the polarization adjustment component 100 is in a second state; and fuse the first and second wavelength channel signals to generate multi-channel color data; wherein the polarization adjustment component 100 emits linearly polarized light in a first polarization direction in the first state and emits linearly polarized light in a second polarization direction in the second state.

[0040] Optionally, the polarization adjustment component 100 is an electrically controlled polarization component, which can respond to the control module 104 and sequentially switch the polarization direction of the X-ray polarized light.

[0041] In this embodiment, the photosensitive device can time-division control the polarization direction of linearly polarized light, so that the first filter structure 1011 and the second filter structure 1012 filter light in their respective polarization states in a time-division manner. The two filter structures complement each other to form a full-spectrum filter for the target wavelength range. The control module 104 reads the first wavelength channel signal and the second wavelength channel signal in a time-division manner, avoiding crosstalk between the first wavelength channel signal and the second wavelength channel signal.

[0042] refer to Figure 4 , Figure 4 This is a schematic diagram of a polarization adjustment component provided in an embodiment of this application. The polarization adjustment component includes a linear polarizer 106 and a liquid crystal panel 105 stacked together. Figure 4 The middle arrow indicates the direction of propagation of the light ray to be detected. Figure 4 This is a schematic diagram of the stacked structure of the linear polarizer 106 and the liquid crystal panel 105 in this direction.

[0043] exist Figure 4In the polarization adjustment assembly 100 shown, the linear polarizer 106 can convert the incident light to be detected into linearly polarized light. The liquid crystal panel 105 is located on the light-emitting side of the linear polarizer 106; the liquid crystal panel 105 can adjust the polarization direction of the incident linearly polarized light based on a set operating voltage, so that the polarization direction of the linearly polarized light switches between a first polarization direction and a second polarization direction.

[0044] like Figure 4 As shown, the liquid crystal panel 105 may include: a first light-transmitting electrode 1051 and a second light-transmitting electrode 1052 facing each other; and a liquid crystal layer 1053 located between the two light-transmitting electrodes. The two light-transmitting electrodes in the liquid crystal panel 105 can control the rotation of liquid crystal molecules in the liquid crystal layer 1053 based on a set operating voltage, thereby controlling the polarization direction of incident linearly polarized light.

[0045] Optionally, the polarizing direction of the linear polarizer 106 can be a second polarization direction, and the linearly polarized light emitted from it has a second polarization direction. The linear polarizer 106 can convert incident light into linearly polarized light. The linear polarizer 106 can be a material with dichroism, typically a polarizer with parallel arrangement of internal long-chain polymer molecules, such as an iodine-based polarizer. Such materials strongly absorb light vibrating in a specific direction, while allowing light vibrating perpendicular to it to pass through smoothly.

[0046] Optionally, the liquid crystal panel 105 includes a twisted nematic liquid crystal layer 1053. When no set operating voltage is applied to the liquid crystal panel 105, the polarization direction of the incident linearly polarized light rotates with the twisting of the liquid crystal molecules, and the emitted light has a first polarization direction. When a set operating voltage is applied to the liquid crystal panel 105 to form a vertical electric field, the axis of the liquid crystal molecules rotates to a vertical state parallel to the vertical electric field, and the emitted light maintains a second polarization direction. Using a twisted nematic liquid crystal, in the absence of voltage, the liquid crystal molecules are arranged in a 90° solenoid-like twist between the two electrodes. When linearly polarized light with the second polarization direction is incident along the long axis of the surface liquid crystal molecules, a waveguide effect (Mauguin effect) occurs, and the polarization direction rotates 90° with the twisting of the molecules before exiting, with the polarization direction following the first polarization direction. When an operating voltage is applied to form a vertical electric field, the vertical electric field causes the liquid crystal molecules to stand upright, the helical structure is destroyed, and the light passes directly through, maintaining the same polarization direction. The emitted light still maintains the second polarization direction. Therefore, the polarization direction of the emission end can be directly controlled by applying low voltage to the two segments of the liquid crystal layer 1053.

[0047] In this configuration, the first polarization direction is perpendicular to the second polarization direction. Thus, based on the synergistic effect of the polarization adjustment component 100 and the filter component 101, the first wavelength range filtering and the second wavelength range passband filtering can be achieved in a time-division manner through the two orthogonal and perpendicular polarization directions, thereby reducing the interference between the first wavelength range filtering and the second wavelength range passband filtering.

[0048] In this embodiment, the control module 104 is used to provide a set operating voltage to the polarization adjustment component 100, so as to control the polarization adjustment component to be in a first state and a second state in a timing sequence, so that the polarization adjustment component 100 emits linearly polarized light in a first polarization direction in the first state and emits linearly polarized light in a second polarization direction in the second state.

[0049] Specifically, when the polarization adjustment component 100 is in the first state, it can emit linearly polarized light in the first polarization direction. At this time, the first filter structure 1011 performs multi-channel passband filtering on the linearly polarized light in the first polarization direction within a first wavelength range. The second metasurface filter unit 1032 in the second filter structure 1012 does not respond to the linearly polarized light in the first polarization direction, blocking its transmission. When the control module 104 controls the polarization adjustment component 100 to switch to the second state, it can emit linearly polarized light in the second polarization direction. At this time, the second filter structure 1012 performs multi-channel passband filtering on the linearly polarized light in the second polarization direction within a second wavelength range. The first metasurface filter unit 1031 in the first filter structure 1011 does not respond to the linearly polarized light in the second polarization direction, blocking its transmission.

[0050] When the polarization adjustment component 100 is in the first state, the photosensitive chip 102 acquires the first wavelength channel signal, and when the polarization adjustment component 100 is in the second state, it acquires the second wavelength channel signal.

[0051] The control module 104 can fuse the first wavelength channel signal and the second wavelength channel signal acquired by the photosensitive chip 102 in a time-division manner to generate multi-channel color data. The fusion process includes calibration and normalization of the original signal. For example, the acquired original signal can be calibrated using a standard light source to form a complete filtered signal, and then the calibrated signal can be normalized. After normalization, the signals of all channels can cover the entire target wavelength range, thereby obtaining accurate color recognition data covering the target wavelength range. This application allows the first and second wavelength ranges of the target wavelength range to be filtered and sensed in a time-division manner, and then the photosensitive information acquired by each channel is fused and superimposed to form overall photosensitive data.

[0052] refer to Figure 5 , Figure 5 This is a schematic diagram of a light filter assembly provided in an embodiment of this application. The light filter assembly 101 includes a light-transmitting substrate 107. Figure 5 The middle arrow indicates the direction of propagation of the light ray to be detected. Figure 5This is a schematic diagram of the stacked structure of the filter structure and the light-transmitting substrate 107 in the filter assembly 101 in this direction. The first filter structure 1011 and the second filter structure 1012 share the same light-transmitting substrate 107, and the two are disposed in different areas on the same side surface of the light-transmitting substrate 107.

[0053] Optionally, the light-transmitting substrate 107 is made of a light-transmitting material, such as a rigid glass plate or a flexible polyimide plate (PI). The material of the light-transmitting substrate 107 is not limited in the embodiments of this application.

[0054] In this embodiment, two orthogonal polarization-designed filter structures can be integrated on the same transparent substrate 107, which greatly simplifies the structure of the filter component 101 and allows the filter component 101 to be mass-produced through wafer-level processes. This makes the integration of the filter component 101 and the photosensitive chip 102 more compact, improves the integration of the photosensitive device, and overcomes the problem of insufficient response band range of a single metasurface chip.

[0055] refer to Figure 6 , Figure 6 This is a schematic diagram of another filter component provided in an embodiment of this application. Figure 5 Based on the filter assembly 101 shown, Figure 6 The filter assembly 101 shown further includes: a first light modulation layer 108, which covers a first region 1071 and exposes a second region 1072; a light-transmitting medium layer 109, which covers the first light modulation layer 108 and the second region 1072; and a metasurface pattern structure 110 located on the surface of the light-transmitting medium layer 109 facing away from the light-transmitting substrate 107. The metasurface pattern structure 110 includes: an array of multiple first metasurface filter units 1031 opposite to the first region 1071; an array of multiple second metasurface filter units 1032 opposite to the second region 1072; and each first metasurface filter unit 1031 and each second metasurface filter unit 1032 corresponding to a channel. Figure 6 In the image, the arrow indicates the direction of propagation of the light ray being detected. Figure 6 This is a schematic diagram of the stacked structure of the filter layers in this direction, and the specific graphic structure of the first metasurface filter unit 1031 and the second metasurface filter unit 1032 is not shown.

[0056] In this embodiment, the first wavelength range is the short-wavelength region of the target wavelength range, and the second wavelength range is the long-wavelength region of the target wavelength range; that is, all wavelengths in the first wavelength range are shorter than those in the second wavelength range. The transmission peak wavelength of each first metasurface filter unit 1031 in the first filter structure 1011 is shorter than the transmission peak wavelength of each second metasurface filter unit 1032 in the second filter structure 1012. Above the first region 1071 of the transparent substrate 107, the first optical modulation layer 108 and the metasurface pattern structure 110 can form a Fabry-Pérot resonance (FP resonance). Above the second region 1072 of the transparent substrate 107, the second metasurface filter unit 1032 is a coupled resonant metasurface structure and can form a coupled resonance.

[0057] Taking the target wavelength range as the visible light band as an example, both the first optical modulation layer and the metasurface pattern structure 110 are set to Ag material. At this time, in the first wavelength range of 400 nm to 600 nm in the short-wavelength region, silver has a small penetration depth for shorter wavelength light, and the light energy is effectively confined between the first metasurface filter unit 1031 and the first optical modulation layer. Relying on the diffraction modulation of the first metasurface filter unit 1031 and the FP resonance formed between the first metasurface filter unit 1031 and the first optical modulation layer, the peak wavelength of the transmission of a specific target channel in the short-wavelength region can be transmitted, while the light of other wavelengths is suppressed.

[0058] As the wavelength increases, the light's penetrating power in silver increases. The light is no longer confined within the FP resonant cavity composed of the two layers of silver material, making effective resonance impossible and significantly deteriorating the filtering effect. Therefore, FP resonance is suitable for short-wavelength filtering but not for filtering in the second wavelength range of 600-780nm in the long-wavelength region. Therefore, for the long-wavelength region, due to the longer wavelength and stronger penetrating power, the second metasurface filter unit 1032 adopts a coupled resonant metasurface structure. This structure can extend the resonant path length of the light wave, effectively lengthening the resonant wavelength and extending the transmission peak to the long-wavelength region. This allows light of a specific resonant wavelength to pass through the coupled resonant metasurface structure, while non-resonant modes are filtered out by the thicker silver second metasurface filter unit 1032, thus achieving high-efficiency bandpass filtering in the long-wavelength region.

[0059] Optionally, the first light modulation layer 108 can be a transparent metal thin film, and can be any one of Ag thin film, Au thin film, Cu thin film, and Al thin film. In this embodiment, the first light modulation layer 108 is preferably an Ag thin film. The first light modulation layer 108 covers the entire first region 1071 and exposes the second region 1072. The transparent dielectric layer 109 can be a silicon dioxide layer, silicon nitride layer, aluminum oxide layer, and polymer layer, etc. In this embodiment, the transparent dielectric layer 109 is preferably a silicon oxide layer. The metasurface patterned structure 110 can be a patterned transparent metal thin film, and can be any one of Ag thin film, Au thin film, Cu thin film, and Al thin film. In this embodiment, the metasurface patterned structure 110 is preferably a patterned Ag thin film.

[0060] exist Figure 6 In the filter component 101 shown, an array of first metasurface filter units 1031 and an array of second metasurface filter units 1032 can be formed in the first region 1071 and the second region 1072 of the transparent substrate, respectively, to form a first green light structure and a second filter structure 1012. The fabrication process of the filter component 101 is simple. Specifically, the required metasurface pattern structure 110 can be formed by using a single patterned transparent metal layer, which can be achieved through conventional photolithography and coating techniques. It does not require controlling the thickness of hundreds of film layers with nanometer-level precision as in interference filters, nor does it require fabricating a high aspect ratio vertical PN junction structure as in vertical silicon absorption color separation.

[0061] In this embodiment, the metasurface patterned structure 110 can be prepared by a patterned transparent metal layer, which is simple to process.

[0062] refer to Figure 7 and Figure 8 , Figure 7 This is a top view of a filter assembly provided in an embodiment of this application, showing a local region corresponding to two adjacent first metasurface filter units. Figure 8 for Figure 7 The image shows a cross-sectional view of the filter assembly. For clarity, Figure 7 and Figure 8 The image only shows two adjacent first metasurface filter units 1031 in the first filter structure 1011. The number and array arrangement of the first metasurface filter units 1031 in the first filter structure 1011 can be set according to requirements, and this application embodiment does not limit this.

[0063] like Figure 7 and Figure 8 As shown, the first metasurface filter unit 1031 includes a plurality of parallel gratings 111, the length direction of which is ( Figure 7The vertical direction (in the middle) is parallel to the second polarization direction. Figure 7 In the two first metasurface filter units 1031 shown, the gratings 111 of each first metasurface filter unit 1031 extend vertically, and the gratings 111 are arranged in parallel with equal spacing in the transverse direction (first polarization direction). The gratings 111 in each first metasurface filter unit 1031 have the same thickness d and the same grating period Px1. The gratings 111 in each first metasurface filter unit 1031 have different linewidths. w Line width w The target channel transmission peak wavelength is matched with that of the corresponding channel of the first metasurface filter unit 1031. Figure 7 and Figure 8 In the two adjacent first metasurface filter units 1031 shown, the width of the grating 111 of the left first metasurface filter unit 1031 is... w W1, the width of the grating 111 of the first metasurface filter unit 1031 on the right. w Let W2 be the integer part of the equation, and W1 be the integer part of the equation.

[0064] In this embodiment, each of the first metasurface filter units 1031 of the first filter structure 1011 can use the same grating 111 thickness d and the same grating 111 period Px, by adjusting the linewidth of the grating 111. w The target channel transmission peak wavelength corresponding to each first metasurface filter unit 1031 can be flexibly adjusted. The first metasurface filter unit 1031 has a simple structure and is easy to process.

[0065] refer to Figures 9-11 , Figure 9 This is a top view of a filter assembly provided in an embodiment of this application, showing a local region between two adjacent second metasurface filter units. Figure 10 for Figure 9 A cross-sectional view of the filter assembly shown. Figure 11 This is a three-dimensional structural schematic diagram of a filter component provided in an embodiment of this application, showing a local region corresponding to a second metasurface filter unit. For clarity of illustration, Figure 9 and Figure 10 The image only shows two adjacent second metasurface filter units 1032 in the second filter structure 1012. The number and array arrangement of the second metasurface filter units 1032 in the second filter structure 1012 can be set according to requirements, and this embodiment does not limit this. Figure 9 The horizontal direction is the first polarization direction, and the vertical direction is the second polarization direction.

[0066] like Figures 9-11As shown, the filter assembly 101 includes a patterned second light modulation layer 112 disposed on the light-transmitting medium layer 109. The second light modulation layer 112 has a metasurface pattern structure 110. The second metasurface filter unit 1032 is a hollow pattern 113 penetrating the second light modulation layer 112. The hollow pattern 113 corresponding to the second metasurface filter unit 1032 includes two arc-shaped slits symmetrical about an axis parallel to the second polarization direction. The two arc-shaped slits are bent in opposite directions to form a coupled resonant metasurface structure. The coupled resonant metasurface structure can extend the resonant path length of the light wave, effectively lengthen the resonant wavelength, extend the transmission peak to the long-wave region, and allow light of a specific resonant wavelength to pass through the coupled resonant metasurface structure.

[0067] In this embodiment, the second optical modulation layer 112 has different thicknesses in the first region 1071 and the second region 1072, and the thickness of the second optical modulation layer 112 in the first region 1071 is less than the thickness in the second region 1072, so that the first filter structure 1011 and the second filter structure 1012 can achieve accurate multi-passband filtering in the first wavelength range and the second wavelength range, respectively.

[0068] like Figure 9 and Figure 10 As shown, the two arc-shaped slits corresponding to different second metasurface filter units 1032 have the same spacing g and the same slit width W3; the outer diameter R of the arc-shaped slits in different second metasurface filter units 1032 is different, and the outer diameter R matches the target channel transmission peak wavelength of the corresponding channel of the second metasurface filter unit 1032. Wherein, the spacing g is the minimum spacing between two back-to-back arc-shaped slits in the same second metasurface filter unit 1032. Figure 9 The outer diameter R of the two semicircular slits facing away from each other on the left side is R1, and the outer diameter R of the two semicircular slits facing away from each other on the left and right sides is R2, where R1 > R2.

[0069] In this embodiment, each of the second metasurface filter units 1032 of the second filter structure 1012 can have the same spacing g and the same slit width W3. By adjusting the outer diameter R of the arc-shaped slit, the target channel transmission peak wavelength corresponding to each second metasurface filter unit 1032 can be flexibly adjusted. The structure of the second metasurface filter unit 1032 is simple and easy to process.

[0070] Taking the visible light band with a target wavelength range of 400nm~780nm as an example, the first wavelength range is set to the short-wave region of the visible light band, 400nm~600nm, and the second wavelength range is the long-wave region of the visible light band, 600nm~780nm. The first filter structure 1011 has 12 first metasurface filter units 1031 arranged in a 4×3 array, and the second filter structure 1012 has 12 second metasurface filter units 1032 arranged in a 4×3 array. Thus, the first filter structure 1011 and the second filter structure 1012 each correspond to 12 filter channels, and the two correspond to a total of 24 filter channels. By adjusting the width of the grating strips 111 in each of the first metasurface filter units 1031, the peak transmission wavelengths of the target channels corresponding to the 12 first metasurface filter units 1031 can be made to be 480nm, 490nm, 500nm, 510nm, 520nm, 530nm, 540nm, 550nm, 560nm, 570nm, 580nm, and 590nm, respectively. By adjusting the outer diameter of the arc-shaped slits in each of the second metasurface filter units 1032, the peak transmission wavelengths of the target channels corresponding to the 12 second metasurface filter units 1032 can be made to be 600nm, 615nm, 630nm, 645nm, 660nm, 675nm, 690nm, 705nm, 720nm, 735nm, 750nm, and 765nm, respectively.

[0071] Taking the filter assembly 101 as an example, where the first light modulation layer 108 and the second light modulation layer 112 are both made of Ag material, and the light-transmitting medium layer 109 is made of silicon dioxide. In the short-wavelength region, in the first metasurface filter unit 1031, the length direction of each grating 111 is parallel to the second polarization direction, and the grating 111 are periodically arranged along the first polarization direction. As described above, the filtering principle of the first metasurface filter unit 1031 is achieved by relying on the diffraction of the grating 111 and the FP resonance between the upper and lower Ag thin films.

[0072] In one embodiment, considering the structural design of the long-wavelength region, the period Py1 of each first metasurface filter unit 1031 along the second polarization direction can be adjusted according to requirements, based on the transmission peak wavelengths of the aforementioned 12 target channels in the short-wavelength region, Px1=240nm, d=30nm. This application embodiment does not limit this. The width of the grating strips 111 in the 12 first metasurface filter units 1031 is... w The correspondence between the peak transmission wavelengths of the 12 target channels in the shortwave region and the peak transmission wavelengths is shown in Table 1 below.

[0073] Table 1 Design parameters for the width of grating 111 in the first metasurface filter unit 1031

[0074] When the grating width in each first metasurface filter unit 1031 is set as shown in Table 1 above, the spectral transmission curve in the short-wavelength region is as follows: Figure 12 As shown.

[0075] refer to Figure 12 , Figure 12 This document describes the spectral transmission curve of a filter assembly in the short-wavelength region along a first polarization direction, as provided in an embodiment of this application. Figure 12 As shown in the spectral transmission curves, filter component 101 exhibits high filtering efficiency in the short-wavelength region (<600nm), and the peak transmission wavelength of the target channel can be easily adjusted by changing the width of the grating. w This is achieved by... The first metasurface filter unit 1031 has a low response value in the long-wavelength region (>600nm), and it is impossible to make it have a better long-wavelength response by simply changing the structural parameters.

[0076] by w Taking a target channel transmission peak wavelength of 560nm as an example, with a wavelength of 86nm, the electric field distribution is as follows: Figure 13 As shown, its filtering characteristic curve for oblique incident light is as follows: Figure 14 As shown.

[0077] refer to Figure 13 , Figure 13 The electric field intensity distribution diagram of a vertical cross-section of a first metasurface filter unit provided in an embodiment of this application. Based on Figure 13 As shown in the electric field distribution, the electric field intensity in the region between the two Ag thin films (i.e., between the first optical modulation layer 108 and the second optical modulation layer 112) is significantly enhanced, and the Ag modulation structure of the top Ag thin film forms a resonance, allowing light of a specific wavelength to pass through. However, as the wavelength increases, the light penetration becomes stronger, making it impossible to form an effective resonance. Therefore, the filtering effect of the first metasurface filter unit 1031 in the long-wavelength region deteriorates.

[0078] refer to Figure 14 , Figure 14 The filtering characteristic curve of obliquely incident light for a first metasurface filtering unit provided in an embodiment of this application. Based on Figure 14 It can be seen that when the incident angle θ increases from 0° to 20°, the peak wavelength of the target channel transmission (560nm) only shifts slightly, and the change in peak size is also small, which ensures its ability to recognize the color of tilted light.

[0079] Compared to the short-wavelength region, the long-wavelength region has a longer wavelength and increased penetration, making the first metasurface filter unit 1031 no longer suitable. In this embodiment, a second filter structure 1012 is designed based on... Figures 9-11The array structure of the second metasurface filter unit 1032 with a double arc-shaped slit is shown. The core design of the second metasurface filter unit 1032 is to increase the resonant path length of the light wave within the periodic dimension by bending the arc-shaped slit, thereby extending the peak wavelength of the target channel transmission to the long-wavelength region.

[0080] When the first filter structure 1011 and the second filter structure 1012 share the same transparent substrate 107 (such as a glass substrate) and the same transparent dielectric layer 109 (such as a silicon dioxide layer), considering the integration compatibility of the short-wavelength and long-wavelength regions on the same filter component 101, the thickness of the transparent dielectric layer 109 can be 170 nm, the spacing g between the two arc-shaped gaps in the same second metasurface filter unit 1032 is 10 nm, the gap width W3 of the arc-shaped gap is 30 nm, and the period Px2 of each second metasurface filter unit 1032 along the first polarization direction is 300 nm. The period of each second metasurface filter unit 1032 along the second polarization direction can be the same as the period along the first polarization direction. The first optical modulation layer 108 and the second optical modulation layer 112 can both be Ag thin films. On the first region 1071, the second optical modulation layer 112 can be a 30 nm Ag thin film, and on the second region 1072, the second optical modulation layer 112 can be a 60 nm Ag thin film. The correspondence between the outer diameter R of the corresponding arc-shaped slits in the 12 second metasurface filter units 1032 and the transmission peak wavelength of the 12 target channels in the long-wavelength region is shown in Table 2 below.

[0081] Table 2 Design parameters of the outer diameter of the arc-shaped slit in the second metasurface filter unit 1032

[0082] When the outer diameter of the arc-shaped slit in each of the second metasurface filter units 1032 is set as shown in Table 2 above, the spectral transmission curve in the long-wavelength region is as follows: Figure 15 As shown. Unlike the first filter structure 1011, the response polarization direction in the second filter structure 1012 is switched to the second polarization direction.

[0083] refer to Figure 15 , Figure 15 The spectral transmission curve of a filter component provided in the application embodiment along the second polarization direction in the long-wavelength region. Based on Figure 15 As shown in the spectral transmission curve, the filter component 101 has a high filtering efficiency in the long-wavelength region (>600nm), and the peak wavelength of the target channel transmission can be easily achieved by adjusting the outer diameter R of the arc-shaped slit.

[0084] In this embodiment, the second metasurface filter unit 1032 employs two opposing arc-shaped slits along the first polarization direction. The symmetrical arrangement of the two arc-shaped slits facing away from each other ensures the symmetry of the first and second polarization directions, making it less sensitive to light incident from an oblique direction. This allows the filter assembly 101 to maintain the transmission peak position and filter performance stability when filtering light in the short-wavelength region, even with non-perpendicular incident light, avoiding peak drift and spectral distortion caused by oblique incidence, and ensuring the accuracy of multi-channel color detection.

[0085] refer to Figure 16 , Figure 16 An electric field distribution diagram of a second metasurface filter unit provided in an embodiment of this application. Figure 16 The left-middle figure (a) shows the electric field intensity distribution of the second metasurface unit on the plane containing the two arc-shaped gaps. Figure 16 Figure (b) in the middle right is a diagram showing the electric field intensity distribution of the center of the second metasurface filter unit 1032 in a cross section perpendicular to the second polarization direction.

[0086] based on Figure 16 It is known that there is strong coupling between the two arc-shaped slits of the second metasurface filter unit 1032. The light wave generates strong resonance in the semi-circular arc-shaped slit path. A specific resonant wavelength can pass through the Ag film, while the non-resonant mode can be completely or almost completely attenuated in the 60nm thick Ag film, thereby achieving accurate multi-passband filtering in the long-wavelength region.

[0087] refer to Figure 17 , Figure 17 This application provides a filtering characteristic curve of a second metasurface unit for obliquely incident light. For obliquely incident light, for the second metasurface filter unit 1032 with an outer diameter R = 80 nm of the arc-shaped slit, the target channel transmission peak wavelength is 676 nm. When the incident angle θ gradually increases from perpendicular incident (0°), the transmission spectrum curve only changes slightly, and it is not sensitive to the oblique angle of the incident light. This allows the filter component 101 to maintain the transmission peak position and filter performance stability when filtering long-wavelength light, even with non-perpendicular incident light, avoiding peak drift and spectral distortion caused by oblique incident light, and ensuring the accuracy of multi-channel color detection.

[0088] Based on the photosensitive device provided in the above embodiments, another embodiment of this application provides a color detection method, which can perform color detection using the photosensitive device provided in any of the above embodiments. This color detection method can be as follows: Figure 18 As shown.

[0089] refer to Figure 18 , Figure 18This is a flowchart illustrating a color detection method provided in an embodiment of this application. The color detection method includes: Step S11: Convert the light to be detected into linearly polarized light through the polarization adjustment component 100, and control the polarization direction of the linearly polarized light to switch between the first polarization direction and the second polarization direction; Step S12: When the light emitted from the polarization adjustment component 100 is in the first polarization direction, it is incident on the first filter structure 1011 of the first region 1071 in the filter component 101 to obtain optical signals of multiple first wavelength channels; when the light is in the second polarization direction, it is incident on the second filter structure 1012 of the second region 1072 in the filter component 101 to obtain optical signals of multiple second wavelength channels; wherein, the first region 1071 and the second region 1072 are different, and the wavelength ranges of the multiple first wavelength channels and the multiple second wavelength channels do not overlap; Step S13: Use the photosensitive chip 102 to sense the light signal of the first wavelength channel and the light signal of the second wavelength channel respectively to obtain multi-channel color data.

[0090] In this embodiment, after the original signal representing multi-channel color data is acquired by the photosensitive chip 102, it can be calibrated using a standard light source signal to form a complete filter signal. refer to Figure 19 , Figure 19 This is the filtering curve of the photosensitive device's filtering component in the visible light spectrum in the embodiments of this application. Based on Figure 19 It is understood that when using the photosensitive device provided in the embodiments of this application to perform dark color detection in the visible light band, it can accurately identify the color of the entire visible light spectrum.

[0091] Based on the photosensitive device provided in the above embodiments, another embodiment of this application also provides a metasurface filter chip, which can be used as follows: Figure 5 As shown, it includes: a light-transmitting substrate 107; a first filter structure 1011 and a second filter structure 1012 disposed on the light-transmitting substrate 107.

[0092] like Figures 6-8 As shown, the first filter structure 1011 includes a plurality of first metasurface filter units 1031. Each first metasurface filter unit 1031 includes a first light modulation layer 108, a light-transmitting medium layer 109 and a second light modulation layer 112 arranged sequentially. The first metasurface filter unit 1031 includes a plurality of parallel strip-shaped metal structures. The first metasurface filter unit 1031 is configured to perform wavelength selective transmission of incident light with a first polarization direction.

[0093] like Figures 9-11As shown, the second filter structure 1012 includes a plurality of second metasurface filter units 1032. Each second metasurface filter unit 1032 includes a pair of C-shaped metal structure slots disposed on the light-transmitting medium layer 109. The pair of C-shaped metal structure slots are configured to form a coupled resonance and perform wavelength-selective transmission of incident light with a second polarization direction. The pair of metal structure slots in the second metasurface filter unit 1032 are not limited to C-shaped slots, but can be semi-circular slots or elliptical slots, etc.

[0094] The first polarization direction is orthogonal to the second polarization direction, and the first metasurface filter unit 1031 and the second metasurface filter unit 1032 correspond to different wavelength ranges.

[0095] Optionally, in the first filter structure 1011, different first metasurface filter units 1031 have different strip-shaped metal structure widths to form multiple first filter channels with different center wavelengths; In the second filter structure 1012, different second metasurface filter units 1032 have different paired C-shaped metal structure gap sizes to form multiple second filter channels with different center wavelengths.

[0096] The color detection method and the metasurface filter chip and photosensitive device embodiments disclosed in the above embodiments have the same or corresponding beneficial effects, and will not be repeated here to avoid repetition.

[0097] The various embodiments in this application are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical parts between embodiments can be referred to interchangeably. The embodiments provided in this application can be combined with each other without contradiction.

[0098] It should be noted that, in the description of this application, the accompanying drawings and embodiments are illustrative rather than restrictive. The same reference numerals throughout the embodiments identify the same structures. Additionally, for understanding and ease of description, the thicknesses of some layers, films, panels, regions, etc., may be exaggerated in the drawings. It is also understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element may be directly on the other element or there may be intermediate elements. Furthermore, "on" means positioning an element on or below another element, but does not inherently mean positioning it above another element according to the direction of gravity.

[0099] The terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the middle.

[0100] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0101] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application 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.

Claims

1. A photosensitive device, comprising: A polarization adjustment component, which can convert the light to be detected into linearly polarized light, and the polarization adjustment component can at least control the polarization direction of the linearly polarized light to switch between a first polarization direction and a second polarization direction; A filter assembly is disposed on the light-emitting side of the polarization adjustment assembly; the filter assembly includes at least a first filter structure and a second filter structure; the first filter structure is used to perform multi-channel passband filtering of linearly polarized light in the first polarization direction within a first wavelength range, and to block linearly polarized light in the second polarization direction; the second filter structure is used to perform multi-channel passband filtering of linearly polarized light in the second polarization direction within a second wavelength range, and to block linearly polarized light in the first polarization direction; wherein the first wavelength range and the second wavelength range do not overlap, and both cover the target wavelength range; A photosensitive chip is disposed on the light-emitting side of the filter assembly; the photosensitive chip is used to sense the light signal output by the filter assembly, and the light signal can characterize multi-channel color data.

2. The photosensitive device according to claim 1, wherein the first filter structure comprises an array of multiple first metasurface filter units with different structural parameters; The second filter structure comprises an array of multiple second metasurface filter units with different structural parameters; in, Each metasurface filter unit corresponds to a different target channel transmission peak wavelength.

3. The photosensitive device according to claim 1, further comprising a control module, the control module being configured to: When the polarization adjustment component is in the first state, the first wavelength channel signal collected by the photosensitive chip is acquired. When the polarization adjustment component is in the second state, the second wavelength channel signal collected by the photosensitive chip is acquired. The first wavelength channel signal and the second wavelength channel signal are then fused to generate multi-channel color data. in, The polarization adjustment component emits linearly polarized light in the first polarization direction in the first state and emits linearly polarized light in the second polarization direction in the second state.

4. The photosensitive device according to claim 1, wherein the filter assembly comprises a light-transmitting substrate; The first filter structure and the second filter structure are disposed on the side surface of the light-transmitting substrate facing the polarization adjustment component. The surface includes a first region opposite to the first filter structure and a second region opposite to the second filter structure. The first region and the second region do not overlap.

5. The photosensitive device according to claim 4, wherein the filter assembly comprises: A first optical modulation layer covers the first region and exposes the second region; A light-transmitting medium layer, the light-transmitting medium layer covering the first light modulation layer and the second region; A metasurface pattern structure located on the surface of the light-transmitting medium layer facing away from the light-transmitting substrate, the metasurface pattern structure comprising: an array of a plurality of first metasurface filter units opposite to the first region; an array of a plurality of second metasurface filter units opposite to the second region; each of the first metasurface filter units and each of the second metasurface filter units corresponding to one channel.

6. The photosensitive device according to claim 5, wherein the first metasurface filtering unit comprises a plurality of parallel-arranged gratings, the length direction of the gratings being parallel to the second polarization direction; The gratings in each of the first metasurface filter units have the same thickness and the same grating period; The gratings in each of the first metasurface filter units have different linewidths, and the linewidths are matched with the target channel transmission peak wavelength of the corresponding channel of the first metasurface filter unit.

7. The photosensitive device according to claim 5, wherein the filter assembly includes a patterned second light modulation layer disposed on the light-transmitting medium layer, the second light modulation layer having the metasurface patterned structure; The second metasurface filter unit is a hollow pattern that penetrates the second light modulation layer; The cutout pattern corresponding to the second metasurface filter unit includes two arc-shaped slits that are symmetrical about an axis parallel to the second polarization direction, and the two arc-shaped slits are curved in opposite directions.

8. The photosensitive device according to claim 7, wherein the two arc-shaped slits corresponding to different second metasurface filter units have the same spacing and the same slit width; The outer diameter of the arc-shaped slit in the second metasurface filter unit is different, and the outer diameter is matched with the target channel transmission peak wavelength of the corresponding channel of the second metasurface filter unit.

9. A color detection method, comprising: The light to be detected is converted into linearly polarized light through a polarization adjustment component, and the polarization direction of the linearly polarized light is controlled to switch between a first polarization direction and a second polarization direction. When the light emitted from the polarization adjustment component is in the first polarization direction, it is incident on the first filter structure in the first region of the filter component to obtain optical signals of multiple first wavelength channels; when the light is in the second polarization direction, it is incident on the second filter structure in the second region of the filter component to obtain optical signals of multiple second wavelength channels; wherein, the first region is different from the second region, and the wavelength ranges of the multiple first wavelength channels and the multiple second wavelength channels do not overlap; A photosensitive chip is used to sense the light signals of the first wavelength channel and the second wavelength channel respectively to obtain multi-channel color data.

10. A metasurface filter chip, comprising: Transparent substrate; A first filter structure and a second filter structure are disposed on the light-transmitting substrate; The first filter structure includes a plurality of first metasurface filter units. Each first metasurface filter unit includes a first light modulation layer, a light-transmitting medium layer and a second light modulation layer arranged in sequence. The first metasurface filter unit includes a plurality of parallel strip-shaped metal structures. The first metasurface filter unit is configured to perform wavelength selective transmission of incident light with a first polarization direction. The second filter structure includes a plurality of second metasurface filter units, each of which includes a pair of C-shaped metal structure slots disposed on the light-transmitting medium layer. The pair of C-shaped metal structure slots are configured to form a coupled resonance and perform wavelength selective transmission of incident light having the second polarization direction. Wherein, the first polarization direction is orthogonal to the second polarization direction, and the first metasurface filter unit and the second metasurface filter unit correspond to different wavelength ranges.

11. The metasurface filter chip according to claim 10, In the first filter structure, different first metasurface filter units have different strip-shaped metal structure widths to form multiple first filter channels with different center wavelengths; In the second filter structure, different second metasurface filter units have different paired C-shaped metal structure slit sizes to form multiple second filter channels with different center wavelengths.

Images