Acta Optica Sinica, Volume. 40, Issue 14, 1406002(2020)
Transverse-Mode Switchable Few-Mode Ring Fiber Lasers
Xiaofeng Li1, Zhe Li2, Wenmao Wu2, Juhao Li1、*, and Fang Ren3
Author Affiliations
1State Key Laboratory of Advanced Optical Communication Systems and Networks, Peking University, Beijing 100871, China2Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China3School of Computer and Communication Engineering, University of Science and Technology Beijing, Beijing 100083, Chinashow less
A few-mode ring fiber laser based on an all-fiber mode multiplexer/demultiplexer (MUX/DEMUX) was designed, which achieved switchable lasing output in LP01, L , LP21, and hybrid modes. Experimental results show that the output lasing mode of the ring fiber laser can be switched between the three lowest-order linearly polarized (LP) modes and hybrid modes by employing a low mode-crosstalk all-fiber mode MUX/DEMUX and a simple 4 × 1 optical switch. Thresholds of 40, 60, and 80 mW and slope efficiencies of 1.2%, 0.82%, and 0.56% were obtained for the LP01, LP11, and LP21 mode operations, respectively. Numerical simulation and parameter optimization of the designed few-mode ring fiber laser structure adequately resolved the wavelength shift problem, with a line width of 3 dB less than 0.032 nm being realized.