A high-power dual-crystal Tm:YLF laser with 80.9% slope efficiency

We demonstrate a high-power continuous-wave Tm:YLF laser with exceptional efficiency, achieved through laser diode end-pumping of dual Tm:YLF crystals in a thermally insensitive resonator at room temperature. The performance of the Tm:YLF laser system has been thoroughly investigated, covering output power, efficiency, power stability, and beam quality. A maximum output power of 45.85 W was achieved with an absorbed pump power of 60.89 W. The slope efficiency and absorbed-to-optical conversion efficiency were 80.9% and 75.3%, respectively. The laser exhibits excellent stability, with an RMS power stability of 0.33%. The beam quality (M²) of the Tm:YLF laser in the horizontal and vertical directions were 1.01 and 1.05, respectively. This high-performance laser source is ideal for pumping holmium-doped crystals to generate 2-μm laser and mid-infrared laser generation via nonlinear optical processes.