A Full-color Holographic Movie Based on Silicon Nitride Metasurface

Metasurface holograms offer numerous benefits such as a wide viewing angle, compact size, and excellent resolution due to their finely spaced structures reaching subwavelength dimensions. However, the challenge lies in the difficulty of dynamically controlling their optical properties post-production to display multiple frames. In this research, we successfully created a multicolor holographic movie based on metasurface by combining 30 frames across blue, green, and red color spectrums at wavelengths of 445nm, 532nm, and 633nm. This was achieved through spatiotemporal multiplexing. Using silicon nitride (SiN) dielectric waveguide meta-atoms allowed us to reach the highest reconstruction speed of 55.9fps with 30 frames. SiN’s low absorption coefficient throughout the visible region, and minimal Fresnel reflectance, which occurs as the meta-atom’s effective index of refraction approaches that of the substrate, contributed to this success. Through careful optimization of fabrication conditions, particularly in reactive ion etching to produce polarization-independent silicon nitride waveguide meta-atoms with a high aspect ratio, we attained remarkable average transmittance and diffraction efficiency of 92.0% and 72.7%, respectively.