Wavelength-switchable single-longitudinal-mode thulium-doped fiber laser at 2.05 µm using a superimposed fiber Bragg grating

• Published in: Infrared physics & technology 2022-05, Vol.122, p.104058, Article 104058
• Main Authors: Guo, Ying, Yan, Fengping, Feng, Ting, Qin, Qi, Han, Wenguo, Cheng, Dan, Yu, Chenhao, Yang, Dandan, Zhou, Hong, Suo, Yuping
• Format: Article
• Language: English
• Subjects: Multi-wavelength thulium-doped fiber laser; Single-longitudinal-mode; Superimposed fiber Bragg grating
• ISSN: 1350-4495; 1879-0275
• DOI: 10.1016/j.infrared.2022.104058

•A single-longitudinal-mode (SLM) thulium-doped fiber laser (TDFL) is enabled by a three-channel superimposed fiber Bragg grating (SI-FBG).•Three single-wavelength operations can be obtained and switched flexibly.•A maximum optical signal-to-noise ratio (OSNR) is 62 dB. Herein, we present a wavelength-switchable single-longitudinal-mode (SLM) thulium-doped fiber laser (TDFL), enabled by a three-channel superimposed fiber Bragg grating (SI-FBG), a compound-subring-cavity (CSC), and an unpumped TDF-based saturable absorber (SA). By adjusting a drop-in polarization controller (DI-PC), three single-wavelength operations can be obtained and switched flexibly. In each operation, the fiber laser exhibited a maximum optical signal-to-noise ratio (OSNR) of 62 dB as well as the wavelength and power fluctuations of ≤0.01 nm and ≤0.641 dB, respectively, in a 50-min time span. Furthermore, the SLM lasing characteristics of the proposed TDFL with the CSC and SA have been investigated in detail.