Emission of single variable-duration nanosecond pulses by a passively mode-locked TEA CO2 laser

A study was made of passive mode locking in a TEA CO₂ laser when the number of beam passes through the amplifying region was increased. Lasing was obtained in pulses of continuously variable duration (0.7–7 nsec) and having intensities of 10–50 MW/cm² with a mode-locking stability of ~90%. It was found possible to generate single pulses in this regime on spacing out a train of pulses by increasing the resonator length and simultaneously giving it a slight misalignment.