Incident light angle and wavelength synchronous detection device and method thereof

Abstract

The application discloses a kind of incident light angle and wavelength synchronous detection device and method thereof, it is related to optical field information detection technical field.Light barrier array (1) is located in light path most upstream, face outside the measured incident light source;Superlens array (2) is placed behind light barrier array (1), and the center of both is kept alignment;Grating coupler array (3) is located near the focal plane of superlens array (2), and with superlens array (2) in space strict alignment;Optical power meter array (4) is connected with the unit output end of grating coupler array (3) by optical fiber array.The application is that incident light is screened by light barrier, and is converged to grating coupler by superlens, when superlens focusing angle and grating coupler coupling angle match, light is coupled to optical power meter, and the angle and wavelength information of incident light are reversed by identifying the number of optical power meter that generates response.The device structure is compact, simple to operate, and can promote the development of new photoelectric detector.

Description

Technical Field

[0001] This invention relates to the field of light field information detection technology, and in particular to a device and method for synchronously detecting incident light angle and wavelength. Background Technology

[0002] Light, as a key carrier of energy and information, possesses multidimensional properties such as polarization, phase, wavelength, and amplitude. By detecting the light field information of a target, key parameters such as its size, position, material, and shape can be obtained. Therefore, achieving free control and multidimensional detection of light fields has significant application value in fields such as 3D facial recognition, autonomous driving, spectral analysis, and remote sensing.

[0003] Traditional photodetectors typically only acquire two-dimensional light intensity information. To perceive more dimensional light field information, additional optical components and mechanical scanning devices are often required, resulting in complex, bulky, and difficult-to-integrate systems. Metasurfaces, as two-dimensional artificial microstructures, can flexibly control the polarization, phase, and wavelength properties of light, providing a new approach to integrating multiple optical functions into a single device.

[0004] In existing technologies, solutions utilize metalens arrays to map the incident angle into a focal spot displacement to detect the angle, or use filtered metasurface arrays to resolve the spectrum through unit cell response. However, for the simultaneous detection of incident light angle and wavelength, existing solutions mostly rely on a combination of discrete spatial optics and integrated optics devices, lacking a fully integrated, unified solution. Furthermore, it is difficult to directly and synchronously decode incident angle and wavelength information without relying on mechanical scanning or complex beam splitting systems. Summary of the Invention

[0005] The present invention aims to overcome the problems of complex systems, large size, difficulty in integration, and inability to simultaneously detect the incident light angle and wavelength in a single integrated device in the prior art, and provides a device and method for synchronous detection of incident light angle and wavelength.

[0006] This invention is achieved through the following technical solution: 1. Incident light angle and wavelength synchronous detection device The device includes an incident light source, an aperture array, a superlens array, a grating coupler array, and an optical power meter array arranged sequentially along the optical path, and the entire device can be packaged in the same module. The connection relationship is as follows: the aperture array is located at the upstream of the optical path, facing the external incident light source to be tested; the superlens array is placed behind the aperture array, and the centers of the two are kept aligned; the grating coupler array is located near the focal plane of the superlens array and is strictly aligned with the superlens array in space; the optical power meter array is connected to the output terminals of each unit of the grating coupler array through the fiber array.

[0007] The aperture array is used to receive the incident light source to be tested and to perform spatial filtering, so that beams with different incident angles are guided to different predetermined areas on the superlens array. Each subarray in the superlens array is designed for a specific center wavelength and consists of multiple superlens units; all superlens units within the same subarray are designed to have the same fixed focusing angle. All units in the grating coupler array have the same structural parameters, and their positions correspond one-to-one with the units in the superlens array. All units in the superlens array and grating coupler array are arranged in a concentric circle manner, and the spatial position of each unit in the array is determined by the polar angle (…). ) and azimuth ( The polar angle is defined as the angle between the line connecting the center of the unit and the normal direction of the device, and the azimuth angle is defined as the angle between the projection of the line connecting the center of the unit in the device plane and the reference axis. The optical power meter array is used to receive and measure the optical power value coupled into the optical fiber.

[0008] 2. A method for synchronously detecting incident light angle and wavelength The application of the above-mentioned device includes the following steps: ① Angle filtering: The incident light source passes through the aperture array, is spatially filtered, and illuminates a specific unit area in the superlens array corresponding to its incident angle; ② Joint encoding: The superlens units located in this unit region and belonging to different subarrays converge the received light at the fixed focusing angle corresponding to their respective subarrays and guide it to the corresponding grating coupler array unit; ③ Wavelength selective coupling: Based on its angular dispersion characteristics, the grating coupler array performs wavelength selective coupling on converged light incident at different focusing angles, so that only a specific wavelength light matching one of the focusing angles is efficiently coupled into the transmission optical path. ④ Signal detection: The efficiently coupled optical signal is transmitted via optical fiber to the corresponding optical power meter unit in the optical power meter array, and a detectable optical response signal is generated; based on the address number of the optical power meter unit that generates the response signal, the two-dimensional angle information and wavelength information of the incident light source are calculated synchronously.

[0009] Compared with the prior art, the present invention has the following advantages: ① High integration: Angle sorting (aperture and superlens), wavelength selection (synergistic dispersion of superlens and grating coupler) and photoelectric detection functions are integrated into a compact planar device, breaking through the integration limitations of traditional optical systems; ②Synchronous detection: It can simultaneously and directly decouple the angle and wavelength information of the incident light without the need for time-division mechanical scanning or subsequent complex spectral reconstruction algorithms; ③ Innovative principle: By leveraging the ability of the superlens to flexibly control the phase of the light field, "spatial encoding" of the incident light angle and wavelength is achieved. Then, the inherent dispersion of the grating coupler is used for "hierarchical decoupling". The principle is novel and the detection efficiency is high. ④ Miniaturization and scalability: The device has a compact structure, is easy to integrate with existing photonic integrated chip platforms, and can easily expand the number of detectable wavelength channels by increasing the number of superlens subarrays or optimizing the design.

[0010] In summary, this invention involves incident light being filtered by an aperture and then converged by a superlens to a grating coupler. When the focusing angle of the superlens matches the coupling angle of the grating coupler, the light is coupled to an optical power meter. By identifying the optical power meter number that generates the response, the angle and wavelength information of the incident light can be retrieved. This device is compact in structure and simple to operate, and can promote the development of new photodetectors. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this device. (a) is a three-dimensional schematic diagram; (b) is a side view and a top view.

[0012] Figure 2 This is a schematic diagram of the operation of this device; (c) is a schematic diagram of the principle; (d) is a schematic diagram of the angular dispersion characteristics of the grating coupler.

[0013] In the picture: 0 - Incident light source; 1-Aperture Array ( ); 2-Tylens Array ( ); 3-Grate Coupler Array ( ); 4-Optical power meter array ( ). Detailed Implementation

[0014] The following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0015] I. Apparatus 1. Overall like Figure 1 The device includes an incident light source 0, an aperture array 1, a superlens array 2, a grating coupler array 3, and an optical power meter array 4 arranged sequentially along the optical path; all components are integrated on a 10mm×10mm fused silica substrate using standard semiconductor micro-nano fabrication and packaging processes to form a compact and robust integrated optical module. The connection relationship is: Aperture array 1 is located at the upstream end of the optical path, facing the external incident light source 1 to be measured, and its center coincides with the optical axis of the optical system; superlens array 2 is placed behind aperture array 1, and the centers of the two are strictly aligned, with a spacing of 1.5 mm; grating coupler array 3 is located near the focal plane of superlens array 2 (e.g., focal length is...). And, and is strictly aligned in space with the superlens array 2; the optical power meter array 4 is connected to the output terminals of each unit of the grating coupler array 3 through the aperture array 1.

[0016] 2. Functional components 0) Incident light source 0 This refers to a beam of light of unknown angle (θ) incident from outside the device. ) and wavelength ( Information was collected, and a supercontinuum light source was selected for testing.

[0017] 1) Aperture Array 1 An aperture is an optical device used in an optical system to limit the beam of light.

[0018] The aperture array 1 is an opaque plate (thin metal plate) with two circular light-transmitting apertures engraved on it. It acts as a direction selector to separate beams of light with different incident angles in space.

[0019] 2) Superlens array 2 A superlens is an optical element that achieves beam modulation and focusing through a specific arrangement of subwavelength nanostructures.

[0020] The superlens array 2 comprises two independently designed superlens subarrays, each designed for the center wavelength. and The superlens unit structure can use dielectric nanopillars (crystalline silicon, silicon nitride) as phase modulation units. Their cross-sectional shapes can be square, square aperture, concentric square aperture, cross, or rectangular cross aperture. The height of the nanopillars can be [missing information]. The dimensions in the x and y directions can vary from 100 nm to 650 nm to achieve phase coverage from 0 to 2π.

[0021] Superlens array 2 receives light filtered by aperture array. All superlenses within the same subarray, despite their spatial positions (θ, Although they are different, they are all designed to move at the same fixed angle. (like or It converges the light rays to the grating coupler unit below it.

[0022] 3) Grating Coupler Array 3 A grating coupler is a device that achieves efficient optical signal coupling between optical fiber and photonic integrated circuit by introducing a periodic grating structure in an optical waveguide.

[0023] Grating coupler array 3 comprises two grating coupler subarrays, all cells in which have the same structural parameters (e.g., an etching depth of 70 nm, based on a 220 nm thick silicon waveguide, and a grating length of...). Width is ).

[0024] The grating coupler array 3 receives light converged from the upper superlens array 2 and performs wavelength-selective coupling based on diffraction phase-matching conditions. When beams from different superlens units are at different angles (e.g., and When light shines on a grating coupler unit, the grating selectively and efficiently couples wavelengths that match the convergence angle (e.g., ...). correspond The light from that path enters the back-end optical path.

[0025] 4) Optical power meter array 4 An optical power meter is an instrument used to measure the magnitude of optical power.

[0026] It receives optical signals transmitted from the grating coupler array 3 via optical fiber, converts them into electrical signals, and outputs them. The address number of each detection unit ( , , or As determined during system design, when a unit generates a significant optical response signal, its number directly corresponds to the angle and wavelength information of the incident light.

[0027] A silicon-based photodetector array monolithically integrated with a grating coupler array is selected, or it is connected to a discrete photodetector array via an optical fiber array.

[0028] 3. Working Mechanism Aperture array 1 serves to differentiate angles, ensuring a single incident direction. , The light from the superlens array 2 only illuminates a specific corresponding unit.

[0029] The superlens array 2 and the grating coupler array 3 are arranged in concentric circles and precisely aligned, with each superlens unit corresponding one-to-one with the grating coupler unit below it in space.

[0030] The design of the superlens array 2 is one of the key technologies. The array contains two subarrays (e.g., , Each subarray is designed for a specific center wavelength (e.g., , ), all superlens units within the same subarray, despite their spatial location ( , Although they are different, wavefront modulation makes them all have the same, pre-set convergence angle (e.g., or ).

[0031] To achieve the above functions, the phase distribution of the superlens unit structure consists of a focusing phase and a compensation phase, and must satisfy: (1) in: It's the focal length. and These are the focal points along the x-axis and y-axis, respectively.

[0032] All units in the grating coupler array 3 have the same structural parameters, including period and etching depth; according to the diffraction phase matching condition, their coupling angle is... Follow the formula: (2) in: The effective refractive index of the waveguide, For the grating period, The wavelength is denoted by λ. This equation shows that for a fixed-structure grating, its optimal coupling angle varies with the wavelength, exhibiting angular dispersion characteristics.

[0033] To achieve efficient coupling between the superlens array 2 and the grating coupler array 3, the grating coupler needs to be optimized for specific wavelengths. Optimal coupling angle Convergence angle of the superlens for this wavelength equal Right now Substituting into formulas (1) and (2) above, we get: (3) The above equation shows that by co-designing the focusing position parameters of the superlens array 2 and the structural parameters of the grating coupler array 3, efficient coupling between the two at a specific wavelength can be achieved.

[0034] Based on the above design principles, for the grating coupler array 3 with defined structural parameters, such as Figure 2 As shown in (d), wavelength The optimal coupling angle is At this point, the coupling efficiency is the highest; while at the angle Below, wavelength The coupling efficiency is close to zero; similarly, the wavelength The optimal coupling angle is Therefore, when the wavelength Light is transmitted through the superlens unit. When the beam converges at an angle to the grating coupler, the high-efficiency coupling condition of the grating coupler can be met; if the same beam of light converges at an angle to the grating coupler, the high-efficiency coupling condition of the grating coupler can be met; When the angle converges to the grating, the coupling efficiency decreases significantly; for other wavelengths ( , In the case of , ..., the same wavelength-angle selective coupling mechanism is followed.

[0035] 4. Work process: Combination Figure 2 (c) and (d) illustrate the device's response to an unknown beam of light (wavelength ). The direction is ( , The detection process of ) when the wavelength is The direction is ( , When the incident light source is illuminated by (), it is first spatially filtered by the aperture array 1, and then illuminated to the location (). , The superlens unit of the superlens array 2 at () and Above (belonging to two sub-arrays); the two superlens units focus the beam at a preset angle. and The elements converge into the corresponding cells of the two subarrays in the grating coupler array 3. Above, due to the grating coupler's wavelength... exist The coupling efficiency is optimal at the angle, while at the angle... The lower coupling efficiency is almost zero; therefore, only the coupling from the superlens unit... The light is efficiently coupled into the grating coupler unit and transmitted via optical fiber to the corresponding unit in the optical power meter array 4. Detected; the system can directly interpret the angle of the incident light by detecting and identifying the optical power meter number that generates the response. , ) and wavelength information ( ), to achieve synchronous detection.

[0036] The above embodiments are only used to illustrate the technical concept of the present invention, and are not intended to limit its scope of protection. Any modifications, equivalent substitutions, or improvements made by those skilled in the art without departing from the principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for synchronously detecting incident light angle and wavelength, characterized in that: It includes an incident light source (0), an aperture array (1), a superlens array (2), a grating coupler array (3), and an optical power meter array (4) arranged sequentially along the optical path. The connection relationship is: The aperture array (1) is located at the uppermost end of the optical path, facing the external incident light source to be tested; the superlens array (2) is placed behind the aperture array (1), and the centers of the two are aligned; the grating coupler array (3) is located near the focal plane of the superlens array (2) and is strictly aligned with the superlens array (2) in space; the optical power meter array (4) is connected to the output ends of each unit of the grating coupler array (3) through the fiber array.

2. The incident light angle and wavelength synchronous detection device according to claim 1, characterized in that: The aperture array (1) is an opaque plate engraved with a circular array of light-transmitting holes; the array contains at least two or more light-transmitting holes; The superlens array (2) comprises at least two superlens subarrays, each subarray consisting of multiple superlens units arranged in concentric circles; The grating coupler array (3) includes at least two grating coupler subarrays, each subarray consisting of multiple grating coupler units arranged in concentric circles; The optical power meter array (4) includes multiple optical power meter units; one end of each optical power meter unit is connected to a unit in the grating coupler array (3) via an optical fiber.

3. The method for synchronously detecting the incident light angle and wavelength using the device according to claim 1 or 2, characterized in that, Includes the following steps: ① After being spatially filtered by the aperture array (1), the incident light source is irradiated into a specific unit region in the superlens array (2) corresponding to its incident angle; ② The superlens units located in this unit region and belonging to different subarrays converge the received light at the fixed focusing angle corresponding to their respective subarrays and guide it to the corresponding unit of the grating coupler array (3); ③ The grating coupler array (3) performs wavelength selective coupling on converged light incident at different focusing angles. When the wavelength and focusing angle meet a specific matching relationship, the optical signal achieves efficient coupling. ④ The optical signal that is efficiently coupled is transmitted through the optical fiber to the corresponding optical power meter unit in the optical power meter array (4) and generates a detectable optical response signal; according to the address number of the optical power meter unit that generates the response signal, the angle information and wavelength information of the incident light source are calculated synchronously.

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