US Patent 7428252 Unstable monoblock laser cavity with integrated beam expander

A monoblock laser cavity includes a plurality of discrete optical components disposed serially on a substrate and sharing a common optical axis. The optical components include a laser rod of gain material, a Q-switch, an OPO crystal, an output coupler, and a positive lens. The output coupler has a convex input end face and a concave output end face, and acts as the expanding lens element of a beam expander, and the positive lens completes the beam expander to improve the beam quality.