Output-stabilized high-repetition-rate 1.545-microm Q-switched Er:glass laser

A newly developed Q-switched Er:glass laser with a long pulse length, suitable for fiber-fault location, is described. A specially prepared athermal rod has made it possible to operate at a 5-Hz repetition rate. A feedback-stabilized Q-switching method involving fluorescence monitoring has been applied to this three-level laser system. A +/-3% power stability (standard deviation) has been obtained for a 1-microsec pulse with a 2-mJ output energy.