HIGH BRIGHTNESS 1908nm TM-DOPED FIBER LASER WITH POWER SCALING TO >75W

Abstract

In this paper, we have studied monolithic diode-pumped Tm-doped fiber laser to be used as a pump source for Ho-YAG systems. The cavity is designed to achieve high optical-to-optical efficiency and robustness against amplified spontaneous emission (ASE) induced parasitic lasing via optimizing the doped fiber length and cavity parameters. Experimentally, we have demonstrated 1907.7 nm fiber laser with an output power of 79 W from 10/130 μm Tm-doped double clad fiber, enabling high brightness and radiance density as well. The laser cavity has a slope efficiency of ~55%, ASE suppression of > 40 dB and a near-diffraction-limited beam quality of M2~1.07.