Single-pixel spectral imaging system based on spatial light wave circuit

Abstract

The application provides a kind of single-pixel spectral imaging system based on spatial light wave circuit, belongs to spectral imaging technical field, including front projection lens, optical matrix signal processing unit, waveguide combiner and monochromatic photoelectric detector, front projection lens is used to project to the object to be imaged;Optical matrix signal processing unit is used to carry out discrete sampling, switch modulation, wavelength separation to the projection light wave formed by front projection lens, and output quasi-monochromatic light;Waveguide combiner is used to carry out channel synthesis to the quasi-monochromatic light output by optical matrix signal processing unit according to the same wavelength principle;Monochromatic photoelectric detector is used to convert the monochromatic light signal synthesized by waveguide combiner into electrical signal.The application adopts optical matrix signal processing unit combined with waveguide combiner, can simultaneously collect the imaging data of all required wavelength light in parallel, so as to shorten the data acquisition time of original single-pixel spectral imaging system based on tunable optical filter.

Description

Technical Field

[0001] This invention belongs to the field of spectral imaging technology, specifically a single-pixel spectral imaging system based on a spatial light wave loop. Background Technology

[0002] Color, as one of the important pieces of information in imaging, is not only often used to identify the shape and outline of a target object, but also to determine its chemical composition. From an optical perspective, color corresponds to the wavelength of light and has spectral distinguishability. Therefore, spectral imaging acquires richer information than ordinary imaging and has significant application value in military, security, and agriculture fields.

[0003] Currently, conventional spectral imagers are mainly based on dispersion technology, filtering technology, and large-size area array photodetector technology, resulting in very high hardware costs. Furthermore, area array photodetector technology is still immature in many bands, especially the infrared band, hindering the development of spectral imagers in these bands.

[0004] Single-pixel imaging technology can achieve imaging effects comparable to those of tens of thousands of pixels using only one pixel. This not only greatly saves on the hardware cost of the detector, but also compresses massive amounts of data, reducing the pressure on data storage and processing.

[0005] Currently, single-pixel spectral imaging technology mainly adds tunable filters to single-pixel technology. Its main system structure includes a spatial light modulator to load the modulation matrix, a focusing lens to concentrate the modulated light energy, and a photodetector to detect the light signal, thereby obtaining single-pixel imaging data of different wavelengths. Its core technology is based on the principle of linear superposition of light energies of different wavelengths. It uses tunable filters to select the wavelength required for spectral imaging and then implements imaging at that wavelength according to a single-pixel imaging algorithm.

[0006] In the process of developing this invention, the inventors discovered that existing single-pixel spectral imaging technologies have at least the following problems:

[0007] Existing single-pixel spectral imaging technology cannot acquire imaging data of multiple wavelengths at once. It not only has poor temporal resolution and disturbance resistance, but also requires an extremely long acquisition time to achieve hyperspectral imaging, making it impractical for engineering applications. Summary of the Invention

[0008] Based on the aforementioned background problems, the present invention aims to provide a single-pixel spectral imaging system based on a spatial optical wave loop. It employs an optical matrix signal processing unit combined with a waveguide combiner, which can simultaneously and in parallel acquire imaging data of all required wavelengths of light, thereby shortening the data acquisition time of the original single-pixel spectral imaging system based on tunable filters.

[0009] To achieve the above objectives, the technical solution provided by the embodiments of the present invention is as follows:

[0010] A single-pixel spectral imaging system based on a spatial optical wave loop includes:

[0011] A front-facing projection lens is used to project the object to be imaged.

[0012] The optical matrix signal processing unit is used to perform discrete sampling, switching modulation, wavelength separation, and output quasi-monochromatic light on the projected light wave formed by the front projection lens.

[0013] A waveguide combiner is used to perform channel combining of the quasi-monochromatic light output by the optical matrix signal processing unit according to the principle of the same wavelength;

[0014] A monochromatic photodetector is used to convert the monochromatic optical signal synthesized by the waveguide combiner into an electrical signal.

[0015] In one embodiment, the front projection lens is formed by at least one optical lens.

[0016] Furthermore, the optical lens is a convex lens or a combination of a convex lens and a concave lens.

[0017] In one embodiment, the optical matrix signal processing unit includes:

[0018] Spatial optical waveguide arrays are used to discretely sample projected light waves to form an optical matrix.

[0019] An integrated waveguide switch array is used for switching modulation of the optical matrix;

[0020] An integrated waveguide coupler array is used to separate the wavelengths of light waves after switching modulation and output quasi-monochromatic light.

[0021] Furthermore, the spatial optical waveguide array consists of several optical waveguides arranged according to spatial topology rules.

[0022] Furthermore, the integrated waveguide switch array consists of several waveguide switches arranged according to spatial topology rules.

[0023] Furthermore, the integrated waveguide coupler array consists of several waveguide couplers arranged according to spatial topology rules.

[0024] In one embodiment, the optical matrix signal processing unit further includes:

[0025] A spatial optical waveguide spacing extender array is disposed on the rear side of the spatial optical waveguide array to extend the waveguide spatial spacing of the spatial optical waveguide array.

[0026] In one embodiment, a single-pixel spectral imaging system based on a spatial light wave loop is characterized by further comprising:

[0027] A data storage unit is used to store the electrical signal output by the monochromatic photodetector; or,

[0028] The information processing unit is used to process the electrical signal output by the monochromatic photodetector to obtain spectral imaging.

[0029] Compared with the prior art, the embodiments of the present invention have at least the following effects:

[0030] 1. The single-pixel spectral imaging system of the present invention includes a front projection lens, an optical matrix signal processing unit, a waveguide combiner, and a monochromatic photodetector. After adjustment, the front projection lens images the target and projects it onto the incident end of the optical matrix signal processing system. The optical matrix signal processing system performs discrete sampling, switching modulation, and wavelength separation on the projected light field, outputting quasi-monochromatic lights that constitute the desired imaging spectral components. The waveguide combiner performs channel synthesis on these quasi-monochromatic lights according to the principle of the same wavelength and sends them to the monochromatic photodetector, thereby realizing spectral imaging. That is, the single-pixel spectral imaging system of the present invention uses an optical matrix signal processing unit combined with a waveguide combiner to simultaneously and in parallel acquire imaging data of all desired wavelengths, thereby shortening the data acquisition time of the original single-pixel spectral imaging system based on tunable filters to 1 / N, where N is the number of wavelengths contained in the spectrum.

[0031] 2. The optical matrix signal processing unit of the present invention also includes a spatial optical waveguide extension array, which can expand the waveguide spatial spacing of the spatial optical waveguide array so as to provide sufficient space for placing an integrated waveguide switch array.

[0032] 3. The single-pixel spectral imaging system of the present invention eliminates the tunable filter, a core component of existing single-pixel spectral imagers, greatly saving the time required to achieve serial acquisition of multi-wavelength data by adjusting the passband wavelength; it also eliminates the spatial light modulator, a core component of existing single-pixel spectral imagers, which not only avoids the generation of unnecessary diffraction orders but also improves the data acquisition rate; and it also eliminates the focusing lens, a core component of existing single-pixel spectral imagers, avoiding the complexity of focusing optical path adjustment.

[0033] 4. The single-pixel spectral imaging system of the present invention adopts an integrated design, which effectively avoids the defects of existing single-pixel spectral imagers such as large size of discrete components, difficulty in adjustment, and complex optical path. It is extremely suitable for being mounted on various vehicles, ships, aerospace vehicles and other mobile measurement fields, and has broad application prospects in military target identification, crop and aquaculture pest and disease control, autonomous driving, gas leak monitoring and other fields. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0035] Figure 1 This is a schematic diagram of the single-pixel spectral imaging system based on a spatial optical wave loop in Embodiment 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the optical matrix signal processing unit in Embodiment 1 of the present invention;

[0037] Figure 3 This is a schematic diagram of the optical matrix signal processing unit in Embodiment 2 of the present invention;

[0038] Figure 4 This is a schematic diagram of the front projection lens in Embodiment 5 of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 invention.

[0041] Existing single-pixel spectral imagers mainly rely on tunable filters to select the wavelength of light to be imaged. They have a distinct serial data acquisition characteristic in terms of time. Not only do they require multiple adjustments of the filter for spectral components, but they also lack real-time performance due to the large amount of acquisition time required.

[0042] To address the aforementioned issues, this invention provides a single-pixel spectral imaging system based on a spatial optical wave loop. After adjustment, the front projection lens images the target in a reduced size and projects it onto the incident end of the optical matrix signal processing system. The optical matrix signal processing system performs discrete sampling, switching modulation, and wavelength separation on the projected light field, outputting quasi-monochromatic lights that constitute the desired imaging spectral components. A waveguide combiner performs channel synthesis on these quasi-monochromatic lights according to the principle of the same wavelength and sends them to a monochromatic photodetector, thereby achieving spectral imaging.

[0043] The single-pixel spectral imaging system of the present invention uses an optical matrix signal processing unit combined with a waveguide combiner, which can simultaneously and in parallel acquire imaging data of all required wavelengths of light, reducing the data acquisition time of the original single-pixel spectral imaging system based on tunable filters to 1 / N, where N is the number of wavelengths contained in the spectrum.

[0044] The technical solution of the present invention will now be described in detail through specific embodiments.

[0045] Example 1

[0046] Single-pixel spectral imaging systems based on spatial optical wave loops, such as Figure 1 As shown, it includes: a front projection lens 1, an optical matrix signal processing unit 2, a waveguide combiner 3, and a monochromatic photodetector 4.

[0047] In this embodiment, the front projection lens 1 is a convex lens with imaging function, capable of imaging the target object and projecting it onto the optical matrix signal processing unit 2. The conjugate surface of the front projection lens 1 to the target object is located at the incident end of the optical matrix signal processing unit 2.

[0048] In this embodiment, the optical matrix signal processing unit 2 is located on the rear side of the front projection lens 1, and is used to perform discrete sampling, switching modulation, wavelength separation on the projected light wave formed by the front projection lens 1, and output quasi-monochromatic light.

[0049] like Figure 2 As shown, the optical matrix signal processing unit 2 includes a spatial optical waveguide array 201, an integrated waveguide switch array 202, and an integrated waveguide coupler array 203 arranged sequentially. The spatial optical waveguide array 201, the integrated waveguide switch array 202, and the integrated waveguide coupler array 203 can be fabricated on the same material, or they can be integrated on the same substrate material using different materials, or they can be fabricated by interlocking channel optical waveguides.

[0050] Specifically, the spatial optical waveguide array 201 is composed of several optical waveguides densely arranged according to spatial topology rules. The spatial optical waveguide array 201 is used to discretize the projected light wave. Discrete sampling specifically refers to introducing a projected light field with a certain spatial size into the incident end of the spatial optical waveguide array 201, so that the spatially continuous projected light field is discretized by the spatial optical waveguide array 201, thereby forming an optical matrix.

[0051] The integrated waveguide switch array 202 consists of several waveguide switches densely arranged according to spatial topology rules. The integrated waveguide switch array 202 is used to switch and modulate the optical matrix. Specifically, the switch modulation refers to selectively modulating the optical matrix through carefully designed electro-optic, magneto-optic, acousto-optic, and other optical waveguide switches, thereby achieving the purpose of purposefully allowing or blocking light in the waveguide to pass through.

[0052] The integrated waveguide coupler array 203 consists of several waveguide couplers arranged densely according to spatial topology rules. The integrated waveguide coupler array 203 is an array designed for the wavelengths required for spectral imaging and has the function of separating light waves of different wavelengths. It is used to separate the wavelengths of light waves after switching modulation and output quasi-monochromatic light.

[0053] In this embodiment, as Figure 1 As shown, the waveguide combiner 3 is located on the rear side of the optical matrix signal processing unit 2, and is used to perform channel combining of the quasi-monochromatic light output by the optical matrix signal processing unit 2 according to the principle of the same wavelength.

[0054] Specifically, the waveguide combiner 3 is provided in multiple forms and is a one-to-many optical wave coupler. In other embodiments, the waveguide combiner 3 can also be formed by multiple optical paths with the function of combining optical waves.

[0055] In this embodiment, as Figure 1 As shown, the monochromatic photodetector 4 is disposed on the rear side of the waveguide combiner 3 and is used to convert the monochromatic light signal synthesized by the waveguide combiner 3 into an electrical signal.

[0056] Specifically, the monochromatic photodetector 4 is provided in multiple forms, and each monochromatic photodetector 4 is used to detect light waves of a specific wavelength, which can detect any wavelength (including the entire spectral band) required by the spectral imaging system.

[0057] The working principle of the single-pixel spectral imaging system in this embodiment is as follows:

[0058] After adjustment, the front projection lens 1 images the target and projects it onto the incident end of the optical matrix signal processing system 2. The optical matrix signal processing system 2 performs discrete sampling, switching modulation, and wavelength separation on the projected light field, and outputs each quasi-monochromatic light that constitutes the required imaging spectral components. The waveguide combiner 3 performs channel synthesis on these quasi-monochromatic lights according to the principle of the same wavelength, and sends them to the monochromatic photodetector 4, thereby realizing spectral imaging.

[0059] Example 2

[0060] Single-pixel spectral imaging systems based on spatial optical wave loops, such as Figure 3 As shown, unlike Embodiment 1, the optical matrix signal processing unit 2 in this embodiment further includes a spatial waveguide extension array 204. The spatial waveguide extension array 204 is disposed between the spatial waveguide array 201 and the integrated waveguide switch array 202, which can expand the waveguide spatial spacing of the spatial waveguide array to provide sufficient space for the integrated waveguide switch array.

[0061] Example 3

[0062] The single-pixel spectral imaging system based on spatial light wave loops differs from Embodiment 2 in that it further includes an information processing unit for processing the electrical signal output by the monochromatic photodetector to obtain spectral imaging.

[0063] Specifically, the information processing unit can be a microcontroller, DSP, FPGA, ARM, etc.

[0064] Example 4

[0065] Unlike Embodiment 2, this embodiment of the single-pixel spectral imaging system based on spatial light wave loop also includes a data storage unit for storing the electrical signal output by the monochromatic photodetector.

[0066] Example 5

[0067] Single-pixel spectral imaging systems based on spatial optical wave loops, such as Figure 4 As shown, unlike Embodiment 1, the front projection lens 1 in this embodiment is composed of a concave lens and a convex lens, which is equivalent to the existing double Gauss standard camera lens. In other embodiments, other camera imaging lenses (zoom or fixed focus) may also be used.

[0068] It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of this invention, and these modifications and improvements all fall within the scope of protection of this invention.

Claims

1. A single-pixel spectral imaging system based on a spatial optical wave loop, characterized in that, include: A front-facing projection lens is used to project the object to be imaged. The optical matrix signal processing unit is used to perform discrete sampling, switching modulation, wavelength separation, and output quasi-monochromatic light on the projected light wave formed by the front projection lens. A waveguide combiner is used to perform channel combining of the quasi-monochromatic light output by the optical matrix signal processing unit according to the principle of the same wavelength; A monochromatic photodetector is used to convert the monochromatic optical signal synthesized by the waveguide combiner into an electrical signal; The optical matrix signal processing unit includes: Spatial optical waveguide arrays are used to discretely sample projected light waves to form an optical matrix. An integrated waveguide switch array is used for switching modulation of the optical matrix; An integrated waveguide coupler array is used to separate the wavelengths of light waves after switching modulation and output quasi-monochromatic light.

2. The single-pixel spectral imaging system based on a spatial optical wave loop according to claim 1, characterized in that, The front projection lens is formed by at least one optical lens.

3. The single-pixel spectral imaging system based on a spatial optical wave loop according to claim 2, characterized in that, The optical lens is a convex lens or a combination of a convex lens and a concave lens.

4. The single-pixel spectral imaging system based on a spatial optical wave loop according to claim 1, characterized in that, The spatial optical waveguide array consists of several optical waveguides arranged according to spatial topology rules.

5. The single-pixel spectral imaging system based on a spatial optical wave loop according to claim 1, characterized in that, The integrated waveguide switch array consists of several waveguide switches arranged according to spatial topology rules.

6. The single-pixel spectral imaging system based on a spatial optical wave loop according to claim 1, characterized in that, The integrated waveguide coupler array consists of several waveguide couplers arranged according to spatial topology rules.

7. The single-pixel spectral imaging system based on a spatial optical wave loop according to claim 1, characterized in that, The optical matrix signal processing unit further includes: A spatial optical waveguide spacing extender array is disposed on the rear side of the spatial optical waveguide array to extend the waveguide spatial spacing of the spatial optical waveguide array.

8. The single-pixel spectral imaging system based on a spatial optical wave loop according to claim 1, characterized in that, Also includes: A data storage unit is used to store the electrical signal output by the monochromatic photodetector; or, The information processing unit is used to process the electrical signal output by the monochromatic photodetector to obtain spectral imaging.

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