Generation of Watt-Level 2.06- $\mu$ m Polarized Light From Diode Wing-Pumped Ho:YLF Laser

We first demonstrate the laser performance of a compact 2.06-μm Ho: YLF laser wing pumped by a fiber-coupled laser diode, which is insensitive to the polarization state of pump source. A maximum output power of 1.44 W, corresponding to a slope efficiency of 41.25%, is obtained. The optimized beam quality factor reaches 2.52 when the output power is about 1 W. Multi-peak laser spectra are observed in the range of 2064.5-2066.6 nm. The output power fluctuation is greatly reduced to about 0.57% of the average power in 50 min. The degree of polarization reaches the level of 96%. The performance in power stability and overall compact structure indicates that diode wing-pumped Ho: YLF laser has great value in gas sensing and precise medical treatment that require a relative high stable output laser.