Nonlinear wavefront engineering with metasurface decorated quartz crystal

Ningbin Mao,Yutao Tang,Kingfai Li,Xuan Liu,Kokwai Cheah,Yang Li,Guanqing Zhang,Guixin Li,Wenhao Tang,Mingke Jin,Yu Chen,Zixian Hu,Xuecai Zhang

doi:10.1515/nanoph-2021-0464

Abstract

Abstract In linear optical processes, compact and effective wavefront shaping techniques have been developed with the artificially engineered materials and devices in the past decades. Recently, wavefront shaping of light at newly generated frequencies was also demonstrated using nonlinear photonic crystals and metasurfaces. However, the nonlinear wave-shaping devices with both high nonlinear optical efficiency and high wave shaping efficiency are difficult to realize. To circumvent this constraint, we propose the idea of metasurface decorated optical crystal to take the best aspects of both traditional nonlinear crystals and photonic metasurfaces. In the proof-of-concept experiment, we show that a silicon nitride metasurface decorated quartz crystal can be used for the wavefront shaping of the second harmonic waves generated in quartz. With this crystal-metasurface hybrid platform, the nonlinear vortex beam generation and nonlinear holography were successfully demonstrated. The proposed methodology may have important applications in nonlinear structured light generation, super-resolution imaging, and optical information processing, etc.

Highlights

Optical wavefront engineering is of critical importance in the areas of optical imaging, optical communication and information processing
In the proof-of-concept experiment, we show that a silicon nitride metasurface decorated quartz crystal can be used for the wavefront shaping of the second harmonic waves generated in quartz
To verify the proposed idea, we experimentally demonstrate nonlinear vortex beam generation and nonlinear optical holography using second harmonic waves generated from the quartz crystal

Summary

Introduction

Optical wavefront engineering is of critical importance in the areas of optical imaging, optical communication and information processing. Recent development in the laser direct writing technique was used to make threedimensional nonlinear photonic crystals [13, 14] These nonlinear photonic crystals can be used for the generation of optical vortex and holographic image at second harmonic frequency [15,16,17,18]. A gold microstructureconjugated polymer system was utilized to generate vortex beam at third harmonic frequency [30]; a metasurfacetungsten disulfide hybrid platform was developed for focusing and beam steering of the second harmonic waves (SHWs) [31, 32]. Our results indicate an easy-to-use and promising platform for realizing compact and efficient nonlinear wavefront engineering and will potentially contribute to the development of nonlinear structured light source and optical information processing, etc

Design and fabrication of the metasurfaces

Characterizations of nonlinear wavefront engineering

Findings

Conclusions