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Enhancing Photon Throughput of Miniaturized Passive Depth-Detection Cameras via Broadband Dispersion-Engineered Metalenses
journal contributionposted on 2023-10-06, 15:03 authored by Zhanyi Zhang, Lingyun Xie, Jian Zhang, Tao He, Jingyuan Zhu, Zhanshan Wang, Xiong Dun, Xinbin Cheng
With the continuous advancement of technology, there is a growing demand for depth-detection cameras with a small footprint and high photon throughput. Metalenses offer an excellent platform for implementing single-lens depth-detection cameras. However, the narrow operational bandwidth of the metalenses used in these miniaturized cameras significantly limits the photon throughput. Here, we propose a broadband dispersionless double-helix metalens (DL-DH metalens) to enhance the photon throughput and mitigate motion blur in miniaturized passive depth-detection cameras. Through engineering the dispersion, the DL-DH metalens was designed to achieve an irrotational double-helix point spread function (DH-PSF) over the broadband wavelength, thus eliminating the depth-detection error caused by chromatic aberration. The operational bandwidth of the fabricated metalens was expanded to 200 nm for obtaining higher-photon throughput, resulting in a 10-fold reduction in the exposure time compared with that observed for a narrow operational bandwidth of 30 nm. The sharp images could be captured by the DL-DH metalens to acquire accurate depth information, even in the presence of moving objects. Our proposed metalens provides a solution for enhancing the photon throughput in miniaturized passive depth-detection cameras operated in low-light environments.
sharp images couldmitigate motion blurexposure time compareddetection error causedhigh photon throughputproposed metalens providesdetection cameras operatednarrow operational bandwidthminiaturized passive depthbroadband dispersionless doubleenhancing photon throughputphoton throughputdetection camerasoperational bandwidthirrotational doublebroadband wavelengthhelix metalensfabricated metalensthus eliminatingsmall footprintobtaining highermoving objectsmetalenses usedmetalenses offerlight environmentslens depthimplementing singlegrowing demandfold reductionexcellent platformengineered metalensescontinuous advancementchromatic aberration30 nm200 nm