Stable and low threshold random fiber laser via Anderson localization

We report a stable and low-threshold Er-doped random fiber laser (RFL) based on a femtosecond-laser-inscribed random-distributed-grating army (RDGA) as the random feedback. The RDGA had a reflectivity of 93.5%, and its properties were numerically analyzed based on the transfer matrix method. The threshold of the laser was significantly reduced to 5.7 mW, and the linewidth was similar to 0.4 pm near the threshold as the Anderson localization effect existing in the RDGA significantly improved the laser quality factor (4 x 10(6)). In addition, we propose a method to select RFL lasing modes by stretching a fiber grating filter used in the cavity with different axial strains. The center wavelength hardly drifted and the maximum jitter value of the peak power was less than 0.12 dB over 1 hour for the selected three lasing modes, which indicated that our laser operation was quite stable. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement