Abstract

Optical edge detection significantly reduces the image information load and is highly sought after in instant image processing. Robustness to the wavelength and polarization of light as well as mechanical vibration is a key requirement for practical applications. Here, a robust optical edge detector is proposed and demonstrated based on a reflective twisted liquid crystal q-plate. The device is composed of a mirror and a 1.46-μm-thick liquid crystal layer with a twist angle of 69.2°. The backtracking of the light inside the twisted medium forms a mirror symmetric twisted design and thus leads to a broadband self-compensated spiral phase modulation. By this means, an optical edge detector with excellent wavelength and polarization independence is presented for both coherent and partially coherent light sources. Additionally, the reflective design makes the system more compact and stable. This work supplies a practical design for robust optical edge detection, which may upgrade existing image processing techniques.

© 2023 Optica Publishing Group

Two-dimensional optical differentiator for broadband edge detection based on dielectric metasurface

Meixue Zong, Yiqing Liu, Jinwen Lv, Shubin Zhang, and Zhengji Xu
Opt. Lett. 48(7) 1902-1905 (2023)

Optical edge detection with adjustable resolution based on cascaded Pancharatnam–Berry lenses

Yingnan Tu, Ruijian Li, Zhenyu Xiong, Hao Wu, Yuan Ren, Zhengliang Liu, Rusheng Sun, and Tong Liu
Opt. Lett. 48(14) 3801-3804 (2023)

Selectively reflective edge detection system based on cholesteric liquid crystal

Tibin Zeng, Jin Xie, Yingjie Zhou, Fan Fan, and Shuangchun Wen
Opt. Lett. 48(3) 795-798 (2023)

Simultaneous chiral polarization and edge enhancement imaging enabled by a single geometric-phase-based element

Yingjie Zhou, Xianglin Ye, Shang Liu, Shizhen Chen, Dongliang Tang, and Fan Fan
Opt. Lett. 48(19) 5085-5088 (2023)

Bragg-Berry mirrors: reflective broadband q-plates

Mushegh Rafayelyan and Etienne Brasselet
Opt. Lett. 41(17) 3972-3975 (2016)