Radiation-balanced silica fiber laser

In optically pumped lasers, heat generated by the quantum defect causes detrimental fluctuations in output mode, frequency, and power. Common heat-mitigation techniques use bulky mechanical coolers that introduce vibrations, leading to laser frequency amplitude noise. Here, we present a radiation-balanced fiber laser, cooled anti-Stokes fluorescence (ASF). The gain medium is silica with 21-µm-diameter core doped 2.06 wt. % Y mathvariant="normal">b 3 + co-doped mathvariant="normal">A mathvariant="normal">l 2 mathvariant="normal">O F- reduce concentration quenching. was core-pumped at 1040 nm create both 1065 ASF cooling atmospheric pressure. We demonstrate maximum power of 114 mW slope efficiency 41% while maintaining near-zero average temperature change. This result could enable development lasers unprecedented coherence stability.