Spatial shaping of coherent waves inside a confocal laser

Abstract : Unusual laser modes can be selected by inserting a pair of mutually matched spatial filters in the Fourier planes of a confocal laser resonator. Experiments using a Nd:YAG laser in the free-running regime show the suitability of the proposed modal filtering technique for synthesis or reconstruction of various laser patterns. Their stability is investigated by space-time streak-camera observations of laser emission.