Abstract

A room temperature, diode-pumped Ho:Tm:YLF laser demonstrated efficient normal mode and Q-switched, single pulse performance using lateral pumping of the laser rod. Ho:Tm:YLF has demonstrated higher gain and lower upconversion rates than the conventional choice, Ho:Tm:YAG. Other parameters influencing the selection of YLF are the cross relaxation of Tm, the relative distribution of the Tm ³F₄ and the Ho ⁵I₇ manifolds including ground-state depletion, and the thermal population of the upper and lower laser levels. Since thermal population of the lower laser level is critical, ostensibly, YAG may appear to be a better choice since the lower laser level has a lower thermal population. However, other factors must be considered. One factor in particular is a greater fraction of the pump energy appears in the Ho ⁵I₇ manifold rather than the Tm ³T₄ manifold when YLF i s used instead o f YAG, which promotes better Q-switched performance.

© 1993 Optical Society of America