Researchers at Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques——Shanghai Institute of Optics and Fines Mechanics (SIOM/China) have achievedresonantly gain-switched from a Ho:LuAG rod laser with a slop efficiency of 83% with respect to absorbed pump power. [Laser Phys. Lett. 8( 2), 120–124 ,2011]

Resonantly pumped by a Tm:YLF laser, the Ho:LuAG laser has been achieved 11.5-W CW output with a slope efficiency of 83%. Operated in the gain-switched mode,the Ho:LuAG rod laser can provide a maximum pulse energy of 4.1 mJ (at 2 kHz) and a narrowest pulse duration of 20 ns. At 5 kHz, the pulse peak power was as high as 91 kW. The laser wavelength was centered at 2130 nm with the T =8% coupler, which blue shifted to 2101 nm when the output coupling was increased to 20%. At 10-W output level, the laser beam was nearly diffraction-limited with M² ～1.02. 

The high-efficiency Ho:LuAG laser possesses excellent power-scaling capability, and provides an effective technique to achieve high-power high-RR and shortduration 2.1-μm laser pulses. This kind of compact and rugged laser sources can find wide applications in the areas such as ranging, remote sensing and medical surgery.