High power all-fiberized and narrow-bandwidth MOPA system by tandem pumping strategy for thermally induced mode instability suppression

被引：15

作者：

Pengfei Ma ^{[1
,2
]}

Hu Xiao ^{[1
,2
]}

Daren Meng ^{[1
]}

Wei Liu ^{[1
]}

Rumao Tao ^{[1
,2
]}

Jinyong Leng ^{[1
,2
]}

Yanxing Ma ^{[1
,2
]}

Rongtao Su ^{[1
,2
]}

Pu Zhou ^{[1
,2
]}

Zejin Liu ^{[1
,2
]}

机构：

[1] College of Advanced Interdisciplinary Studies,National University of Defense Technology

[2] Hunan Provincial Collaborative Innovation Center of High Power Fiber Laser,National University of Defense Technology

来源：

High Power Laser Science and Engineering | 2018年 / 6卷 / 04期

基金：

中国国家自然科学基金;

关键词：

advanced laser technology and applications; design; fiber laser and applications; high power laser; laser amplifiers; laser systems; modeling; narrow linewidth; optimization;

D O I：

暂无

中图分类号：

TN24 [激光技术、微波激射技术];

学科分类号：

0803 ; 080401 ; 080901 ;

摘要：

An all-fiberized and narrow-bandwidth master oscillator power amplification(MOPA) system with record output power of 4 kW level and slope efficiency of 78% is demonstrated. Tandem pumping strategy is tentatively introduced into the narrow-bandwidth MOPA system for thermally induced mode instability(TMI) suppression. The stimulated Brillouin scattering(SBS) effect is balanced by simply using one-stage phase modulation technique. With different phase modulation signals, SBS limited output powers of 336 W, 1.2 kW and 3.94 kW are respectively achieved with spectral bandwidths accounting for 90% power of ～0.025, 0.17 and ～0.89 nm. Compared with our previous 976 nm pumping system, TMI threshold is overall boosted to be >5 times in which tandem pumping increases the TMI threshold of >3times. The beam quality(M～2　factor) of the output laser is well within 1.5 below the TMI threshold while it is ultimately saturated to be 1.86 with the influence of TMI at maximal output power. Except for SBS and TMI, stimulated Raman scattering(SRS) effect will be another challenge for further power scaling. In such a high power MOPA system, multidetrimental effects(SBS, SRS and TMI) will coexist and may be mutual-coupled, which could provide a well platform for further comprehensively investigating and optimizing the high power, narrow-bandwidth fiber amplifiers.

引用

页码：53 / 59

页数：7