Abstract

Matched to the water absorption at 1.9-μm wavelength, lùgli peak power and lùgli rep. rate laser beams are required for medical application. One of the best lasers satisfying such requirements is a simple diode-end-pumped thulium doped crystalline laser with the active Q-switch. Taking into consideration the several thulium doped hosts developed in last 2 decades (see e.g. Ref. 1,2), we have chosen the YLF crystal as a gain medium. In this paper the properties of the acousto-optically Q-switched Tm:YLF laser (see Fig. 1) are presented. The fiber coupled (400 pm core diameter) laser diode bar of 30-W was used for pumping. The diode was operating in cw or quasi-cw regime with the emission peak at the 792-mn wavelength. The relay optics (3:5) was focusing the pumping beam into the 0.8-imn spot inside the active crystal; the caustic was ~ 5-imn long. The uncoated with 3.5% dopant Tm:YLF rod of 03 x8mm size wrapped with indium foil was mounted in copper heat-sink maintaining the 293°K temperature of coolant water.

© 2007 IEEE