Patent ID: 8488635

Claim:
An actively Q-switched laser based on UV illumination, comprising: a pump source; a dichroic mirror having one end optically facing said pump source; a gain medium optically facing another end of said dichroic mirror; a polarizer having one end optically facing another end of said gain medium; a quarter wave plate having one end optically facing another end of said polarizer; an electro-optic lithium niobate crystal having one end optically facing another end of said quarter wave plate, at least one side of said electro-optic lithium niobate crystal being electrically connected to a Q-switch driver to have the crystal function as a Q-switch; a source of UV illumination directed to illuminate a side surface of said electrical-optic lithium niobate crystal with UV light to dissipate pyroelectric surface charges associated with the lithium niobate crystal and maintain an extinction ratio above 100 through a temperature range extending as low as −40 degrees Celsius, the extinction ratio being defined as P incident /P r ; and an output mirror to receive an output from said Q-switch and produce a laser emission.