Selection of high-power nanosecond pulses from large-aperture CO2 oscillators

Abstract
A high‐contrast 6‐J 3‐ns pulse has been obtained from an injection mode‐locked TEA CO2 oscillator using an extracavity SF6‐He saturable absorber to suppress the prepulse energy to <1 μJ and an intracavity semiconductor transmission switch to suppress postpulses. The techniques described in this paper will allow the frequency and transverse‐mode control of an oscillator to be maintained to much higher powers than are presently possible.