Frequency-agile electro-optically Q-switched CO2 laser for DIAL measurements

An intracavity piezoelectrically tuned étalon was used to permit rapid wavelength tuning of an electro-optically Q-switched CO2 laser. The laser wavelength could be swept sequentially through the entire 10-μm P branch. Alternatively, as required for operation in a single laser DIAL system, the output could be switched rapidly between two or more prescribed transitions. The observed settling times were typically a few milliseconds.