Small-pixel infrared focal plane detector based on metasurface lens

Abstract

The invention discloses a small-pixel infrared focal plane detector based on a metasurface lens. The small-pixel infrared focal plane detector based on the metasurface lens comprises an infrared focal plane detector body and the metasurface lens formed at a substrate. The metasurface lens is composed of a plurality of small cylinders with sub-wavelength scales, the positions and the diameters of the small cylinders are arranged according to a phase rule, and the metasurface can modulate wavefront of incident light so that the incident light can be focused on an absorption layer of a detector pixel. Compared with a traditional infrared focal plane detector, the infrared focal plane detector has the advantages that focusing light spots in the sub-wavelength magnitude can be achieved, the pixel size can be reduced to the wavelength magnitude, and development of a planar focal plane device towards smaller pixels and higher pixel density is facilitated. Meanwhile, under the condition that the light response of the device is not changed or improved, the dark current of the device is reduced, the signal-to-noise ratio is improved, and photoelectric crosstalk between pixels is inhibited.

Description

technical field [0001] The invention relates to an infrared focal plane detector and a metasurface micro-nano structure with a focusing effect, in particular to an InP-based avalanche photodiode (APD) focal plane detector with a small pixel and high pixel density. Incident photodetector. Background technique [0002] With the development of the times, the status of photoelectric detectors is gradually improving. In aerospace, military industry, and civil automatic driving and communications, photoelectric detectors play an indispensable role, especially infrared focal plane detectors. It is developing towards the trend of large area array, small pixel and high density. [0003] Dark current, photoresponse, uniformity, crosstalk, etc. are several important indicators for evaluating focal plane detectors. As the area array becomes larger and larger, considering the uniformity and device size factors, the size of a single pixel is getting smaller and smaller. How to ensure hi...

AI Technical Summary

Problems solved by technology

As the pixel size decreases, the effective fill factor decreases and optical coupling losses increase

At present, the commonly used traditional plano-convex microlenses rely on the phase difference caused by the thickness difference to achieve focusing. It is difficult to further reduce the image distance and pixel size under the premise of ensuring high optical coupling efficiency.

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