Solid-state laser passively Q-switched in a new geometry

A new passive Q-switching geometry of a laser cavity has been proposed. In the proposed scheme, the volume of the passive Q-switch just partially overlaps the intracavity laser beam cross-section, leading, however, to the entire beam modulation. This technique was applied for passive Q-switching of a flash-lamp pumped multimode YAG:Nd³⁺ laser by LiF:F₂⁻ crystals. The giant pulse laser action threshold has been detected in the proposed geometry, and is lower than that in the scheme where the passive Q-switch operates in the traditional manner. Stable giant pulse oscillation of 1064 nm wavelength with a pulse duration of 24 ns, pulse energy of 450 mJ, and pulse repetition rates of up to 100 Hz, have been obtained.