Passive <i>Q</i>-switch at 1.53 μm using divalent uranium ions in calcium fluoride

Abstract

Using a U2+:CaF2 passive Q-switch for the Er:glass laser, 20 ns, 3 mJ pulses were obtained. This is the shortest duration passive Q-switched pulse obtained for this laser without intracavity focusing and without optical damage. The measured U2+:CaF2 absorption cross section and relaxation lifetime are compared with those of U2+:SrF2 and U2+:BaF2.