Efficient resonantly pumped tape cast composite ceramic Er:YAG laser at 1645 nm.

Laser operation of a composite ceramic Er:YAG rod is demonstrated at 1645 nm with a slope efficiency of 56.9% under resonant pumping at 1532.3 nm. This is believed to be the first reported composite ceramic Er:YAG laser and also the first reported use of a tape cast technique for producing laser ceramics.

Multiple pulse laser-induced damage phenomena in silicates.

Multiple pulse laser-induced bulk damage has been studied in fused silica and borosilicate glass. The fluence dependence and pulse repetition frequency dependence of the damage make it clear that laser irradiation promotes damage on subsequent pulses, and the evidence favors attribution of the effect to transient entities such as point defects rather than larger imperfections such as inclusions. However, the influence of preirradiation defects on damage thresholds is small, and a luminescence experiment places low limits on the possible concentration of conduction band electrons prior to damage. The constraints these results place on possible mechanisms of multiple damage are briefly discussed.