3 kW narrow-linewidth all-fiber amplifier with near diffraction limited beam quality. (20th March 2019)

• Record Type: Journal Article
• Authors: Chu, Qiuhui; Shi, Yi; Wen, Jing; Ouyang, Lie; Zhao, Lei; Wang, Jianjun; Lin, Honghuan; Jing, Feng; Tang, Chuanxiang
• Is Part Of: Laser physics. Volume 29:Number 5(2019)
• Publication Date: 2019-03-20
• Subjects: fiber laser -- stimulated Brillouin scattering -- phase modulation; Lasers -- Periodicals; 621.36605
• DOI: 10.1088/1555-6611/aaff56
• Languages: English
• ISSNs: 1054-660X

Abstract

Abstract: A theoretical model is established to simulate the stimulated Brillouin scattering (SBS) effect in fiber amplifiers using white noise signal (WNS) phase-modulated seed. Based on the theoretical model, the influences of amplifier structure and cut-off frequency of WNS on SBS threshold are discussed in detail. Through theoretical analysis, optimized amplifier structure and phase modulation signal are achieved to suppress SBS, and a fiber laser based on a main oscillator power amplifier with counter-pumped scheme is established. The oscillator, with 3 dB spectral linewidth of 48 GHz, is produced by a WNS phase-modulated single-frequency seed. The amplifier uses a 915 nm diode laser pump and 25/400 Yb-doped optical fiber. The output power reaches 3.02 kW at 1064 nm, with 3 dB root-mean-square linewidth of 48 GHz. Amplified quality is obtained with M, M at maximum power.