Opto-Electronic Advances, 2018, 1 (7): 180003, Published Online: Jan. 10, 2019
Fiber-based mode converter for generating optical vortex beams
Abstract
In this work, an all-fiber-based mode converter for generating orbital angular momentum (OAM) beams is proposed and numerically investigated. Its structure is constructed by cascading a mode selective coupler (MSC) and an inner elliptical cladding fiber (IECF). OAM modes refer to a combination of two orthogonal LPlm modes with a phase difference of ±π/2. By adjusting the parameters and controlling the splicing angle of MSC and IECF appropriately, higher-order OAM modes with topological charges of l = ±1, ±2, ±3 can be obtained with the injection of the fundamental mode LP01, resulting in a mode-conversion efficiency of almost 100%. This achievement may pave the way towards the realization of a compact, all-fiber, and high-efficiency device for increasing the transmission capacity and spectral efficiency in optical communication systems with OAM mode multiplexing.
Ruishan Chen, Jinghao Wang, Xiaoqiang Zhang, Junna Yao, Hai Ming, Anting Wang. Fiber-based mode converter for generating optical vortex beams[J]. Opto-Electronic Advances, 2018, 1(7): 180003.