All-fiber third-order orbital angular momentum mode generation employing an asymmetric long-period fiber grating
Author(s): He, XD (He, Xiaodong); Tu, JJ (Tu, Jiajing); Wu, XW (Wu, Xiaowen); Gao, SC (Gao, Shecheng); Shen, L (Shen, Lei); Hao, CL (Hao, Chenglong); Feng, YH (Feng, Yuanhua); Liu, WP (Liu, Weiping); Li, ZH (Li, Zhaohui)
Source: OPTICS LETTERS Volume: 45 Issue: 13 Pages: 3621-3624 DOI: 10.1364/OL.394333 Published: JUL 1 2020
Abstract: The third-order orbital angular momentum (OAM(+/- 3)) guided mode generation is demonstrated for the first time, to the best of our knowledge, by employing an asymmetric long-period fiber grating (AS-LPFG). The proposed AS-LPFG is modeled by coupled local-mode theory, which is extended to the coupling of core modes and is fabricated by multicycle scanning ablation with increasing power in a six-mode fiber. The experiments demonstrate that one fabricated AS-LPFG can convert the LP01 mode to the third-azimuthal-order (3AO, LP31 or OAM(+/- 3)) guided mode with efficiency of similar to 99.8%. The model and the method presented, in principle, can be used to generate any other high-order modes. (C) 2020 Optical Society of America
Accession Number: WOS:000546808900071
PubMed ID: 32630914
ISSN: 0146-9592
eISSN: 1539-4794
Full Text: https://www.osapublishing.org/ol/abstract.cfm?uri=ol-45-13-3621