Study of frequency stabilization for electro-optical Q-switched radio-frequency-excited waveguide CO2 laser using build-up time method.

An electro-optical Q-switched RF-excited Z-fold CO(2) waveguide laser was designed, which can output a Q-switched laser and a cavity-dumped laser synchronously. The build-up time method is presented to stabilize the laser frequency. A closed-loop control system was designed to keep the laser oscillating at the peak of the gain curve by measuring the pulse build-up time continuously and controlling the cavity length. In the experiment, the variations for the pulse build-up time and cavity-dumped laser output power with time were recorded in a period of time. The frequency fluctuation is less than ±16 MHz.