High-Power, Compact, and Stable Side-Pumped Tm:YAG Laser Diode for 2.02 μm Output

A rod-shaped Tm:YAG solid-state laser pumped from the side by a high-power, compact, and stable laser diode (LD) was introduced. The Tm:YAG crystal was double-end bonded and pumped from the side by a laser module consisting of three LDs with a wavelength of 780nm, achieving high-power laser output. To reduce the device size, a symmetrical straight short cavity was built, and a single-channel water cooling method was used. The highest continuous laser output of 119 W at 2.02 μm was obtained at a cooling temperature of 12℃, with an optical-to-optical conversion efficiency of 18% and a slope efficiency of up to 32.7%. The system can maintain maximum stable output power within 2 hours, with power fluctuations of less than 1%. The beam quality factors in the x and y directions were measured to be 21.01 and 21.68, respectively.