High speed tuning mechanism for CO2 lidar systems

A method for rapidly tuning lasers is presented. The system utilizes a rotating eight-sided mirror and a fixed grating. It is demonstrated that the entire CO2 lasing spectrum can be tuned at effective rates of up to 400 Hz. It is shown that, although the pulse energy is diminished as the tuning rate is increased, the loss comes from the tail of the pulse, and the peak power is almost unchanged. In addition, the tuning method preserves the spatial beam profile while contributing a minimum of beam steering.