Power scalability of a linearly-polarized narrowband random fiber laser in an all-fiber MOPA structure with 0.1 nm linewidth

Abstract

In this manuscript, we demonstrate an all-fiberized master-oscillation-power-amplifier (MOPA) structured linearly-polarized narrowband random laser. The seed source is a narrowband random-polarized random fiber laser (RFL) in a half-opened cavity with a maximum output power of 0.981 W and a linewidth of 0.1 nm. Utilizing a polarizationdependent isolator as a polarizer, a linearly-polarized narrowband seed laser can be obtained. As for the main amplifier, a pump-limited 381.1 W amplified linearly-polarized narrowband random laser can be achieved with a linewidth of 0.13 nm (33.36 GHz) and a polarization degree of 92.33% (~11 dB). The performance of the system is limited by the generation of mode instability (MI) effects, and hence, the worsening of temporal stability and the reduction of beam quality. Furthermore, significant tail broadening of the output spectrum can be measured. As the output and backward powers increase monotonously with the boosting of pump power, we conclude that further power scaling of this system with good linewidth, polarization, beam quality and temporal stability performance can be achieved with effective mitigation of the MI effect. This work can expand our comprehension on the spectral evolution property of RFL in the power scaling process and provide a possible solution for the obtaining of powerful linearly-polarized narrowband fiber source.

3.5 kW bidirectionally pumped narrow-linewidth fiber amplifier seeded by white-noise-source phase-modulated laser

“…The pump threshold of the RFL seed is about 1 W; with the scaling of the pump power, the output power grows rapidly to ~600 mW. Then a one-stage amplification chain, similar to the structure of the pre-amplifier in [16,24], is utilized to scale the RFL seed power to ~27 W.…”

Ultrafast convergent power-balance model for Raman random fiber laser with half-open cavity

“…Raman random fiber laser (RRFL) combines the features of nano-particle based random lasers [1] with easy fabrication and simple configuration, and those of conventional Raman fiber lasers with wavelength agility [2,3] and high efficiency [4][5][6], attracting extensive attention in recent years [7][8][9][10]. RRFL was first proposed in 2010 by using a long telecommunication fiber [11], which naturally shows advantages in the field of long-distance distributed amplification [12,13], and remotely point sensing [14,15].…”

Watt-level green random laser at 532 nm by SHG of a Yb-doped fiber laser

“…Where traditional laser schemes are based in resonant cavities for feedback generation, RDFLs use the Rayleigh scattering of a long fiber as distributed mirror, generating a modeless-behavior laser [2,3]. The research in this field has led to the generation of ultra-high power RDFLs from hundreds of Watts [4] to kWs [5,6], narrower linewidth RDFLs up to sub-gigahertz [7], polarized output RDFLs [8][9][10], tunable RDFLs [11][12][13] and pulsed generation [14,15]. Gain in RDFLs can be generated from Raman scattering [2,16], by rare earthdoped fibers [12,13] or a hybrid of both [17].…”