Influence of the Penning process on the noise of gas-discharge lasers

An investigation was made of plasma fluctuations in He–Cd, He–Zn, He–Xe, and He–Ne lasers. It was found that Penning excitation gives rise to fluctuations in the discharge, associated with sum and difference combinations of striations, the latter causing appreciable deterioration in the noise characteristics of the radiation. An analysis is made of methods of decreasing the output radiation noise of lasers utilizing mixtures of helium and readily ionized elements by suppressing or synchronizing the striations. It is shown that if the striations are synchronized, the electron temperature increases, which increases the output power of ionic lasers and reduces that of lasers utilizing atomic transitions in readily ionized elements.