Compact Meta-optics for Virtual Reality and Depth Perception

Yao-Wei Huang
National Yang Ming Chiao Tung University
Friday, August 18, 2023
2:00 pm
ISEB 1200


      Dielectric metasurfaces composed of sub-wavelength artificial structures enable
spatial modulations of phase, polarization, dispersion on demand, leading to a plethora
of meta-optics. Due to the flat-profile nature of metasurfaces, they demonstrate some
potential in replacing the bulky three-dimensional optical elements in the optical
systems. In this invited talk, I will report on our recent developments in large-scale RGB-
achromatic metalenses and depth perception with structured light [1-4]. We build up an
inverse-design framework for aperiodic large-scale complex meta-optics in three
dimensions, which alleviates computational cost for both simulation and optimization via
a fast-approximate solver and an adjoint method, respectively [1-2]. In experiment, we
demonstrate up to 1-cm-diameter polarization insensitive metalens that achieve high-
NA and diffraction-limited achromatic focusing of the primary colors by using our
inverse-design framework. The metalens is composed of ~1 billion meta-atoms. To
illustrate the potential of this approach, we demonstrate a future virtual-reality platform
by using our meta-eyepieces with laser back-illuminated micro liquid crystal display.
Additionally, we experimentally demonstrate integration of meta-hologram with
photonics crystal surface emitting laser (PCSEL) that achieve generation of ~ 44K light
dots within field of view (FOV) of 158 ° [3-4]. The meta-hologram is fabricated directly
on GaAs substrate and followed by integrating with PCSEL. We realize 3D facial depth
map by projecting light dots on statue David and calculating its depth map with the block
matching algorithm. The dimension of meta-hologram and aperture of the PCSEL is
around 300 µm. Our approach miniaturizes the volume and solves the bulky issue of
commercial dot projectors (e.g., in iPhone's Face ID) and 3D sensing technology. These
state-of-the-art metasurfaces open a path to a new type of platform for today’s optical
devices and lay promising groundwork of metasurface systems in the future decades
toward advanced nanophotonics and technologies.

[1] Z. Li, P. Lin, Y.-W. Huang, J.-S. Park, W. T. Chen, Z. Shi, C.-W. Qiu, J.-X. Cheng, and F.
Capasso, “Meta-optics achieves RGB-achromatic focusing for virtual reality,” Science
Advances 7(5), eabe4458 (2021).
[2] Z. Li, R. Pestourie, J.-S. Park, Y.-W. Huang, S. G. Johnson, and F. Capasso, “Inverse design
enables large-scale high-performance meta-optics reshaping virtual reality,” Nature
Communications 13, 2409 (2022).

[3] W.-C. Hsu, C.-H. Chang, Y.-H. Hong, H.-C. Kuo, and Y.-W. Huang, “Compact structured
light generation based on meta-hologram PCSEL integration,” Discover Nano 18, 87 (2023).
[4] W.-C. Hsu, C.-H. Chang, Y.-H. Hong, H.-C. Kuo, and Y.-W. Huang, “Meta-optical elements
and PCSEL based structured light for monocular depth perception” Under review.



Yao-Wei Huang is currently an Assistant Professor and Yushan Young Scholar in the Department of Photonics at the National Yang Ming Chiao Tung University (NYCU), Taiwan. He was a Research Associate at Harvard and NUS, working with Prof. Federico Capasso and Prof. Cheng-Wei Qiu in dielectric metasurfaces and their applications in nano-optic endoscope, vortex metasurface laser, and virtual reality. He received his PhD in Applied Physics from the National Taiwan University in Taiwan in 2015 under the supervision of Prof. Din Ping Tsai in plasmonic metasurface holograms. He was a Visiting Research at the Caltech, working with Prof. Harry A. Atwater in tunable metasurfaces. His research interests include nanophotonics, metasurfaces, inverse design, structured light, dispersion engineering, computational visual sensing, and their innovative applications in extended reality and LiDAR. His work is focused on metasurface applications for the betterment of human well-being. His work on these topics has led to more than 50 scientific journals and patents, such as Nature Photonics, Advanced Materials, Light: Science & Applications, Nature Communications, Science Advances, ACS Nano, Nano Letters, etc. He delivered 12 invited talks at various conferences including MRS, SPIE, SPP, and META. He is a recipient of the 2021 Yushan Young Scholarship and the 2019 Prize for Frontiers of Biomedical Optoelectronics.

Howard Lee