Chirality-selected second-harmonic holography with phase and binary amplitude manipulation

Abstract

Recently, multi-functional nonlinear wavefront control has attracted extensive attention. In particular, nonlinear holography can carry information and has potential for application in information encoding and computing. However, it is quite challenging because it puts forward higher requirements with nonlinear conversion efficiency and wavefront control performance. Here, we propose and experimentally demonstrate chirality-selected second-harmonic (SH) holography based on a Au–WS₂ nonlinear optical interface. It is realized using nonlinear geometry phase control with a sub-wavelength resolution. Furthermore, binary amplitude manipulation is introduced by replacing specific rectangular nanoholes with square nanoholes. This indicates that the average intensity of holograms is increased by 39% and the hologram variation coefficient is decreased by 44% in comparison with that in pure geometry phase control. In addition, the SH signal from the monolayer WS₂ with a large second-order susceptibility is further enhanced by the strong local-field in Au nanoholes, leading to a high SH conversion efficiency of 10⁻⁶. Therefore, it offers an important stepping stone towards multi-functional SH holography, which may have potential for application in nonlinear information encoding and processing.