Open AccessCascaded stimulated Brillouin scattering erbium-doped fiber laser generating orbital angular momentum beams at tunable wavelengths
Author(s) -
Jinghao Wang,
Jialang Zhang,
Anting Wang,
Xianghua Jiang,
Junna Yao,
Qiwen Zhan
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.425533
Subject(s) - optics , brillouin scattering , angular momentum , materials science , fiber laser , fiber bragg grating , wavelength , physics , optical fiber , optoelectronics , quantum mechanics
We experimentally demonstrate a method to obtain central wavelength tunable orbital angular momentum beams with switchable topological charges (+1 or -1) in a stimulated Brillouin scattering erbium-doped fiber laser. Multiwavelength operation is achieved through cascaded stimulated Brillouin scattering in a single-mode fiber with a length of 6 km initiated by an external Brillouin pump. High-efficiency mode conversion between the fundamental mode and the orbital angular momentum modes is realized through a broadband two-mode long-period fiber grating. High-purity orbital angular momentum beams with up to 10 stable wavelength channels with a tuning range of 35 nm are achieved, which is the highest number of operating wavelengths and tuning range in an all-fiber laser for orbital angular momentum beam emission to the best of our knowledge. Both the operational central wavelength and number of operating wavelengths can be tuned by adjusting the primary pump power and the center wavelength of the tunable bandpass filter in conjunction with changing the Brillouin pump wavelength.