Tunable and switchable multi-wavelength fiber laser based on polarization hole burning effect and Sagnac loop mirrors

Abstract

In this paper, a stable highly tunable and switchable multi-wavelength fiber laser is presented. It is based on the filtering characteristics of the Sagnac loop mirror and the polarization-dependent devices, the polarization hole burning effect is induced to generate multi-wavelength output with high optical signal-to-noise ratio and narrow 3 dB linewidth, optical signal-to-noise ratio is about 50 dB and linewidth is less than 0.02 nm. The tunable bandwidth is about 30 nm, which covers almost the entire C-band. By the adjusting polarization controller, the number and wavelength spacing of laser emissions can be controlled and switched. The single-wavelength exhibits good power and wavelength stability, the peak power fluctuation is less than 0.04 dB and the wavelength drift is less than 0.04 nm, and the wavelength spacing of the dual-wavelength can be tuned from 0.67 to 27.4 nm. In the proposed structure, multi-wavelength up to 6 laser emissions can be obtained span from 1528 to 1562 nm.