Toward high-power nonlinear fiber amplifier

Abstract

Stimulated Raman scattering (SRS) effect is considered to be one of the main obstacles for power scaling in general-type fiber lasers. Different from previous techniques that aim at suppressing SRS, nonlinear fiber amplifier (NFA), which manipulates and employs the SRS for power scaling in rare-earth-doped fiber, is under intensive research in recent years. In this paper, the authors will present an all-round study on this new kind of high-power fiber amplifier. A theoretical model is proposed based on the rate equation and amplified spontaneous emission (ASE), with random noise taken into account. By numerical solving of the theoretical model, the power scaling potential, heat analysis and advantages in suppressing the undesired backscattering light are quantificationally analyzed for the first time. Then two different types of high-power NFAs are demonstrated individually. Firstly, a laser diode pumped NFA has reached kilowatt output power, and the results agree well with theoretical predictions. Secondly, a tandem-pumped NFA is proposed for the first time and validated experimentally, in which 1.5 kW output power has been achieved. The authors also briefly discuss several new issues relating to the complex nonlinear dynamics that occur in high-power NFAs, which might be interesting topics for future endeavors.

High-power double-cladding fiber lasers: A 30-year overview

“…, 并有 望成为一种获得万瓦级高功率输出的新方案 [117] . 激光的研究与发展带来了新的机遇, 同时有望在引力 波探测 [118] 、激光加速器 [119] 等大科学工程(大科学装 置)中得到应用.…”

Editorial: HPLSE special issue on fibres for high-power lasers

“…Investigation on extreme frequency shift in silica fiberbased high-power Raman fiber laser [8] 9. Towards high power nonlinear fiber amplifier [9] 10. Efficient high harmonics generation by enhancement cavity driven with a post-compressed FCPA laser at 10 MHz [10] 11.…”

“…• Large mode area fibres for power scaling Submissions for this special issue cover from the development of active fibres itself to the advances in fibre lasers and fibre amplifiers. Papers described research on high-power ytterbium-doped fibre lasers and amplifiers operating in continuous wave [1,2] , nanosecond regime [3] , picosecond regime [4] and femtosecond regime [5] ; erbiumdoped tunable fibre amplifier [6] ; Raman fibre laser [7,8] and nonlinear amplifier [9] ; high harmonic generation for UV Correspondence to: Y. Wang, Institute of Laser Engineering, Beijing University of Technology, Beijing 100124, China. Email: wangyingying@bjut.edu.cn wavelength [10] as well as a review of ytterbium-doped fibres [11] .…”

“…[7], simulation shows by combining the advantages of the Tm-doped fibre lasers (TDFLs) at and the tellurite fibre, hundreds of watts level mid-IR RFL at and tens of watts level at could be expected. Stimulated Raman scattering (SRS) effect could also be utilized to fully unleash the power-scaling potential of high-power fibre amplifier [9] .…”

Fabrication of kW-level chirped and tilted fiber Bragg gratings and filtering of stimulated Raman scattering in high-power CW oscillators

“…Fiber lasers have been widely used in many fields, including industrial processing [1,2] , biomedicine [3,4] and communication [5] , due to their compact structure, high efficiency and high spatial beam quality [6] . With increasing demand for high power, stimulated Raman scattering (SRS) has become one of the main factors limiting the development of fiber lasers [7] . To solve this problem in recent years, an increasing number of researchers have focused their attention on using specially structured fiber gratings to suppress the SRS in fiber lasers.…”