基于锥形掺镱光纤实现20kW高光束质量激光输出OACSTPCD

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.