Ultra-compact structured light projector with all-dielectric metalenses for 3D sensing

Abstract

The current structured light projector is generally large in size. In order to realize a compact and small-sized module, this paper proposes to substitute the conventional refractive lenses with the most popular meta-lenses to achieve compactness. This paper focuses on the analysis of the metalens performance requirements, design methods and simulation results. Varying diameters of these nano-pillar structures are used to adjust the phase of the electromagnetic wave to realize flat lens. Two types of all-dielectric meta-lenses are designed for using in ultra-compact structured light projector. Parameters of two meta-lenses at wavelength of 850nm are depicted as follows: the focal length f=500um, aperture size D=100um, numerical aperture NA=0.1, FWHM=0.323λ and the focal length is f=50um, aperture size is D=100um, numerical aperture is about NA=0.7, FWHM=0.598λ, respectively. At last, simulation results show that this solution can achieve an ultra-compact structured light projector, which is 77% smaller than the traditional technology.