Tunable and Switchable Dual-Wavelength SLM Narrow-Linewidth Fiber Laser with a PMFBG-FP Filter Cascaded by Multi-Ring Cavity

• Published in: Photonics Vol. 9; no. 10; p. 756
• Main Authors: Gao, Mingquan, Yin, Bin, Lv, Yanzhi, Sang, Guofeng, Hou, Benran, Li, Haisu, Wang, Muguang, Wu, Songhua
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2022
• Subjects: Bandwidths; Bragg gratings; composite sub-cavity; Doped fibers; Equipment and supplies; Erbium; Fabry-Perot interferometers; Fiber lasers; Fiber optics; Holes; Laser outputs; Lasers; Light; narrow linewidth; Optical communication; Optical filters; orthogonal linear polarization; Polarization; Signal to noise ratio; single longitudinal mode; Spectrum allocation; tunable dual-wavelength; Wave division multiplexing; Wavelength; Wavelengths
• ISSN: 2304-6732; 2304-6732
• DOI: 10.3390/photonics9100756

A single longitudinal mode (SLM) dual-wavelength switchable erbium-doped fiber laser (DW-EDFL) based on polarization-maintaining fiber Bragg grating Fabry–Perot cavity (PMFBG-FP) cascaded multiple sub-ring cavities (MSCs) is proposed. A PMFBG-FP with a narrow-band transmission peak and MSCs was implemented as an optical filter to achieve stable dual-wavelength laser output and guaranteed SLM status. By stretching the PMFBG, a highly stable dual-wavelength tunable output could be achieved with a maximum tuning interval of 0.17 nm. The optical signal-to-noise-ratio (OSNR) at dual-wavelength lasing was higher than 57 dB, and the optimal wavelength and power fluctuations within 0.5 h were 0.01 nm and 0.79 dB, respectively. Meanwhile, the measured linewidths of each wavelength were 1.55 kHz and 1.65 kHz, respectively. The measured polarization states of the two laser wavelengths were linear and orthogonal, with a degree of polarization (DOP) of nearly 100%.