Intracavity active frequency shift: a novel method of shifting the frequency of pulsed lasers

We have developed a new technique for shifting the frequency of a TEA CO(2) laser that utilizes a Pockels cell in the main cavity and an acousto-optic frequency shifter in the subcavity. The amount of frequency shift was controllable by the gate pulse width of the Pockels cell. The maximum shift from the line center achieved was 1.4 GHz at the 10P(20) line, limited by the gain bandwidth. This method, which keeps the single-longitudinal-mode oscillation, can be widely applicable to pulsed lasers with a wide gain bandwidth, such as high-pressure CO(2) lasers.