A large-angle dot projector is the key optical component in Apple’s Face ID, which casts a structured dot pattern onto the face so as to create a 3D facial map. The dot projection system often employs an array of VCSEL units. Light from the VCSEL array is first collimated by a lens system, and then replicated by a two-dimensional grating into a large angular range. Simulation of such systems would require an appropriate model of the VCSEL source, a dependable handling of the lens system, and a rigorous method for gratings with relatively small periods. In VirtualLab Fusion, this connection of different field solvers is par for the course; we use this ability below in a demonstration of how a dot projector works.
Working Principle Demonstration of the Dot Projector with Physical Optics Modeling
As a demonstration, this Use Case shows the working principle of a typical optical system for dot projection, including the physical optics modeling of the VCSEL array source, the lens and the beam splitter.
Design and Rigorous Analysis of Non-Paraxial Diffractive Beam Splitter
The Fourier modal method (FMM) is applied for the rigorous evaluation of non-paraxial diffractive beam splitters, which are initially designed using IFTA and the thin-element approximation.
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