Actively Q-switched, diode pumped thulium laser

Abstract

6 W of output power and near 50% slope efficiency with respect to absorbed pump power was demonstrated in free-running mode for a short, 40-mm long resonator. The uncoated, with 3.5% dopant of thulium YLF rod of ⌀ 3 × 8 mm size wrapped with indium foil was mounted in copper heat-sink maintaining 293 K temperature of coolant water and inserted in a short, 40-mm long resonator. For pumping the fiber coupled (0.4 mm core diameter) laser diode bar at 792-nm wavelength was deployed. The fused silica acousto-optic modulator with above 80% diffraction efficiency for 25-W power of RF was taken as the Q-switch for such a laser. In the best case of Q-switching mode up to 2-mJ output energy with 20-ns pulse duration corresponding to 100-kW peak power was demonstrated for rep. rate of a few Hz. Emission wavelength was around 1904 nm for both free-running and Q-switching regimes.

High repetition rate, tunable, Q-switched diode pumped Tm:YLF laser

“…For Q−switching we have used water−cooled acousto−optic modulator made of 45−mm long fused silica, operating at radio frequency 40.7 MHz with maximum power of 25 W [57,58]. In fact it was the largest element of a laser head which deter− mined its size.…”

Comparative optical study of thulium-doped YAlO3and GdVO4single crystals

“…Room-temperature diode-pumped CW operation thulium laser can be observed in different crystals such as fluorides [1], garnets, scheelites, and orthovanadates. In recent years, Tm:YAlO 3 [2,3] and Tm:GdVO 4 [4] was broadly studied on their laser performances.…”

The acousto-optical Q-switched Nd:GGG laser

“…Therefore all solidstate Q-switched miniature lasers have attracted a great deal of attention [1][2][3][4]. Acousto-optic Q-switching is one way to obtain the high peak power short pulse.…”