Metasurface-Based Depth Sensing and Janus Metasurfaces

Yao-Wei Huang^1*

¹Department of Photonics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

* Presenter:Yao-Wei Huang, email:ywh@nycu.edu.tw

Structured light has become a cornerstone technology for three-dimensional depth sensing, widely adopted in consumer electronics. However, conventional vertical-cavity surface-emitting lasers with diffractive optical elements systems face inherent challenges in output power, beam divergence, and optical alignment, limiting further miniaturization. To address these issues, we develop a monolithically integrated metasurface–photonic-crystal surface-emitting laser (metasurface-PCSEL) dot projector, achieving small form factor and high optical power. The metasurface hologram, optimized for the PCSEL’s divergence profile, enables dense and uniform dot projection for depth reconstruction. Integrated into a chip scale dot projector, the device exhibits a 2450-fold volume reduction and 28.7 % lower power consumption compared with commercial modules, while successfully recovering object depth profiles. In parallel, we demonstrate the first dielectric Janus metasurfaces operating in the visible spectrum. By engineering meta-atoms with controllable geometry and orientation, directionally asymmetric generation of orbital angular momentum and holographic imaging are achieved within a single layer design. Together, these results establish a versatile platform for low-power, high-performance depth sensing and multifunctional polarization-phase control, paving the way toward compact optical engines for 3D facial recognition, extended-reality systems, and future metasurface-integrated photonic devices.

Keywords: Metasurfaces, Monolithic Integration, Structured Light, Orbital Angular Momentum, Hologram