Method of improving the frequency repeatability of the intensity stabilized HeNe laser

Abstract

A method of improving the frequency repeatability of a two-mode helium–neon laser starting from different initial conditions has been developed. The approach is based on locking the laser when a certain number of laser modes is observed. In order to avoid ambiguity we propose to tie the initial number of laser modes to the value of the intermodal frequency. Experiments proved that with the suggested design it is possible to lock the laser on the desired mode regardless of the initial conditions. In the experiments the frequency repeatability of the laser was equal to its frequency stability.