Passive Q switching of a neodymium laser by a Cr4+:YAG crystal switch

Theoretical and experimental investigations were made of passive Q switching of a neodymium laser by a Cr⁴⁺:YAG switch. Analytic expressions were derived for estimating the output energy of the TEM₀₀ mode of a passively Q-switched laser from the known parameters of the Cr⁴⁺:YAG switch, of the active element, and of the cavity. The adopted description makes it possible to cover the range from generation of the first spike of a free-running transient to generation of a giant pulse. An experimental study was made of the dependence of the output energy on the cavity parameters, on the material of the active element (in this investigation it was Nd:YAG and Cr, Nd:GSGG), and on the angle of rotation of the Cr⁴⁺:YAG switch. The experimental results obtained agreed to within 30% with calculations.