Stabilization of internal-mirror He–Ne lasers

Abstract

Simultaneous frequency and amplitude stabilization of a commercial internal-mirror He–Ne laser by a new simple method is reported. In this method, the back beam intensity of one polarization of the orthogonally polarized modes is fed back as a heater current to control the cavity length of the laser. The relative frequency stability and amplitude stability achieved are, respectively, ±2.5 × 10−9 and ±0.13% over a period of 1 h.