基于锥形掺镱光纤实现20 kW高光束质量激光输出

20 kW fiber laser with high beam quality enabled by tapered ytterbium-doped fiber

摘要: 锥形光纤能够有效兼顾非线性效应抑制和模式控制，具备实现高功率、高光束质量光纤激光的潜力。近期国防科技大学研制了锥形掺镱光纤，采用1018 nm光纤激光后向级联泵浦实现了20.2 kW 激光输出，光束质量β因子平均值优于2，拉曼抑制比为33 dB。研究结果展示了锥形光纤在实现万瓦级高光束质量激光方面的优势。

Abstract: The tapered fiber with varied core diameter along the longitudinal direction has a unique advantage in balancing Stimulated Raman Scattering (SRS) suppression and beam quality, making it a promising approach for purchasing high power laser with high beam quality. Recently, a monolithic high power fiber laser counter pumped by 1018 nm fiber lasers has been experimentally established employing tapered ytterbium-doped fiber made in house. A maximum power of 20.2 kW is achieved with the beam quality factor β<2 and Raman-suppression ratio of 33 dB. The results have demonstrated the great potential of tapered fiber in power scaling to tens of kW fiber laser while achieving good beam quality.