Self-started stable pulsing operation of random fiber laser

TL;DR

This paper demonstrates a novel method for achieving stable pulsing in random fiber lasers through passively induced spatiotemporal gain modulation, overcoming traditional cavity limitations and enabling simple, low-cost pulsed laser sources.

Contribution

It introduces a new passive gain modulation technique for stable pulsing in random fiber lasers, expanding understanding and potential applications of RFLs.

Findings

Achieved stable, regular pulse trains in RFLs.

Discovered pump hysteresis and bistability phenomena.

Analyzed the dynamics of pulsing operation.

Abstract

Unlike traditional fiber laser with defined resonant cavity, random fiber laser (RFL), whose operation is based on distributed gain and feedback via Rayleigh scattering and stimulated Raman scattering in long passive fiber, has fundamental scientific challenges in pulsing operation for its remarkable cavity-free feature. Here, we propose and experimentally realize the passively spatiotemporal gain modulation induced self-started stable pulsing operation of counter-pumped RFL. Thanks to the good temporal stability of employed pumping amplified spontaneous emission source and the superiority of this pulse generation scheme, stable and regular pulse train can be obtained. Furthermore, the pump hysteresis and bistability phenomena with the generation of high order Stokes light is presented and the dynamics of pulsing operation is discussed. This work extends our comprehension of temporal property of RFL and provides an effective novel avenue for the exploration of pulsed RFL with structural simplicity, low cost and stable output.