A high-power dual-crystal Tm:YLF laser with 80.5% optical-to-optical efficiency

We demonstrate a high power continuous-wave Tm:YLF laser with high efficiency via employing laser diode end-pumped dual Tm:YLF crystals in a thermally insensitive resonant cavity. 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 46.65 W was achieved with an absorbed pump power of 57.98 W. The slope efficiency and optical-to-optical conversion efficiency with respect to absorbed pump power were 86.8% and 80.5%, 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.