For the advancement of XR headset device technology, the projection screen and display technologies are a major focus of discussion. The ToF sensor system used for detecting human viewing area at a given power/space budget is also considered an inevitable feature. We report on the constructed systems and the achieved performances with newly developed refractive-diffractive hybrid lenses, a diffuser (Platanus®) and a dot projector (Ardisia®). These lenses were designed using simulator-based ray tracing and a Maxwell equation analysis, and subsequently fabricated using SCIVAX’ nanoimprinting technology. These lenses were customized with VCSELs to cover the wide range of field of illumination (FOI) from 30 to 150 degrees. Platanus® presented considerably uniform and controllable illumination with high phase uniformity over shorter distances, thus we believe it meets the high-resolution sensing requirements for XR. Ardisia® gave high intensity dots without showing the zeroth order light and any collimation lenses. And its intensity could be even higher with an increased number of VCSEL emitters, without changing the dot count as would be the case for an ordinary DOE, so that long-range illumination is easily achievable. Ardisia® with a FOI of 60x45 degrees enabled illumination over 10 m with an optical power of only 2 W, suggesting that the efficiency and compactness of Ardisia® is suitable for 3D sensing optics for XR applications. And the same can be adopted in automotive applications such as for driver monitoring system (DMS) and potentially LiDAR. In this paper, several experimental results for ToF system are presented.

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T. Nakamura, Z. Yang, D. Ogawa, H. Nakagome, A. Nawata, and S. Tanaka, ""Better than DOE optics" solution in ToF sensors for wearable XR device," Proc. SPIE 12449, Optical Architectures for Displays and Sensing in Augmented, Virtual, and Mixed Reality (AR, VR, MR) IV, 1244911 (Presented at SPIE AR | VR | MR: January 30, 2023; Published: 16 March 2023); https://doi.org/10.1117/12.2656545.