Wide range retina-like scanning based on liquid crystal optical phased array. (April 2022)

• Record Type: Journal Article
• Authors: Tang, Mingyuan; Cao, Jie; Hao, Qun; Cheng, Yang; Zhang, Fanghua
• Is Part Of: Optics and lasers in engineering. Volume 151(2022)
• Publication Date: 2022-04
• Subjects: Beam scanning -- Liquid crystal optical phased array -- Retina-like -- Angular magnification; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2021.106885
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: Achieve efficient retina-like circular scanning with beam splitting. Because of the time cost of LCOPA, it is necessary to improve the efficiency of bionic scanning with beam splitting. The combination of sub-aperture method and the array division multiplexing method is realized in this paper to meet the variable spot size. Realize the function of human retina, lens and fovea gaze control with flexible scanning strategy. Limited by LCOPA and energy distribution of echo signals, the half-angular breadth of principle maximum is determined. So the mathematical expression of three dimensional retina-like scanning is improved to meet the application of LIDAR imaging. On the other hand, to solve the difficult cause by intricate target with different size or location of retina-like imaging. Human lens-like and fovea gaze control strategy is used in this flexible scanning proposed in this paper. Angular magnification system is used to meet the need of large field of view and enhance the contrast of the far-field spot. Compared with the traditional angular magnification system, the proposed method is more compact and only act on the effective area, which eliminate the zero-order spot caused by the pixelated sampling of LCOPA. Abstract: A retina-like scanning method based on liquid crystal optical phased array (LCOPA) is proposed to improve field of view and efficiency. The functions of human retina, lens and fovea gaze control are achieved with optimized designed scanning strategy. Beam splitting method and angular magnification system are used to meet the requirements of the efficient scanning and large FOV. The models are verified by several experiments and the results show that the scanning performance well with the flexible retina-like strategy, especially for eccentric fovea. The scanning FOV is magnified 2.2 times and the average scanning error is less than 5%.