Spectral characteristics of radiation emitted by a YAG:Nd³⁺laser with a saturable absorber in the form of an LiF crystal containing F₂⁻centers

Abstract

An experimental investigation was made of the spectral characteristics of radiation emitted by a YAG:Nd3+ laser in which an LiF crystal containing F2− centers was used as a passive switch. Single-frequency emission and mode locking operation regimes were investigated. In the single-frequency regime the minimum width of the emission line was 5×10−3 cm−1 for a single pulse. The frequency selection mechanism involved spatially inhomogeneous saturation of the absorption. Mode locking took place in a ring resonator when a saturable crystal filter with an initial transmission 0.7 was used. The use of a switch containing color centers made it possible to generate picosecond pulses simply and reliably.