基于准连续超表面的宽带高效率边缘检测器件

Broadband and high-efficiency edge detection device based on quasi-continuous metasurface

本文利用准连续纳米带组成的超表面设计了一种光学微分器件,并实现了对光学图像的一维边缘检测。该器件通过改变准连续纳米带的空间取向实现0~2π的几何相位调控,且能在较宽的波段范围内保持较高的能量效率。仿真结果表明,当照明波长从400 nm增加至1000 nm时,该准连续器件均能实现清晰的边缘检测效果。其能量效率最高为90.27%(600 nm波长处),平均能量效率为64.57%(400 nm~1000 nm)。可以预期,本文所提方法能促进准连续超表面在图像信息处理、超快光学模拟计算等方面的应用。

In this paper,we design an optical differential device based on quasi-continuous metasurface and realize one-dimensional edge detection of an optical image.By changing the spatial orientation of quasi-continuous nanostrips,the device achieves geometric phase in the range of 0~2π,and maintains high energy efficiency over a wide wavelength range.The simulation results show that when the illumination wavelength increases from 400 nm to 1000 nm,the quasi-continuous meta-device can achieve clear images for the target edge.The maximum energy efficiency is 90.27%(the incident wavelength is 600 nm)and the average energy efficiency is 64.57%(the incident wavelength changes from 400 nm to 1000 nm).It can be expected that the proposed method can promote the application of quasi-continuous metasurface in image information processing and ultrafast optical computation.