Abstract

Small signal gain coefficients as high as 0.23 cm^-1 for pi polarization and 0.18 cm^-1 sigma polarization have been obtained in a diode- pumped pulsed Ho:Tm:LiYF₄ (YLF) at room temperature with the help of a cw single longitudinal mode probe laser operating at 2.063 μm. Recently there has been considerable interest in high power diode pumped 2 μm lasers for detection of wind velocities and CO₂ and H₂O vapor in the atmosphere. Most of the previous high gain amplifier studies have been done using flashlamp pumped Ho:Tm:Cr:YAG and Ho:Tm:Er:YLF. Practical diode pumped 2 μm Q-switched amplifiers will require high gain as well as efficient pump energy storage and extraction from Ho ions in Ho:Tm doped laser materials. The gain measurements reported in this paper investigate gain, efficient storage, and extraction of pump energy at room temperature.

© 1994 Optical Society of America