High-spectral-purity random Raman fiber laser oscillator with full-open cavity counter-pumped by random lasing. (June 2023)

• Record Type: Journal Article
• Authors: Qi, Tiancheng; Tian, Jiading; Yang, Yousi; Du, Shanshan; Fu, Guohao; Wu, Yunlun; Li, Dan; Yan, Ping; Gong, Mali; Xiao, Qirong
• Is Part Of: Optics & laser technology. Volume 161(2023)
• Publication Date: 2023-06
• Subjects: Fiber laser -- Stimulated Raman scattering -- Rayleigh scattering -- Spatiotemporal gain-modulation; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2023.109145
• Languages: English
• ISSNs: 0030-3992

Abstract

Abstract: Raman fiber lasers with high spectral purity and simple structure are essential for the high-power fiber lasers beyond the conventional emission band of active dopants. In this paper, we demonstrate a compact random Raman fiber laser (RRFL) oscillator with spectral purity of over 99%. The RRFL is generated in a full-open cavity which is counter-pumped by a random ytterbium-doped fiber laser with half-open cavity. They share the same piece of passive fiber to form the cavity, a fiber Bragg grating separates the signal light and pump light for the output. This configuration promises the compactness and high spectral purity of the RRFL. Leveraging the spatiotemporal gain-modulation, the RRFL can provide both continuous-wave output and stable pulsed output through adjusting the pump power. The output laser of continuous-wave operation and pulsing operation exhibits spectral purity of 99.4% and 99.5% around 1134 nm, respectively. This work offers a simple and robust solution for high-spectral-purity Raman fiber lasers of both continuous-wave operation and pulsed operation of hundred-watt level. Highlights: Random Raman fiber lasers (RRFLs) extend the operating wavelengths of fiber lasers. Spatiotemporal gain-modulation enables RRFL hundred-watt-level CW and pulsed output. Signal spectral purity is over 99% by splitting pump wave in counter-pumped RRFL. Multifunctional optical components in RRFL ensure the compactness and robustness.