Frequency stabilisation of the He-Ne laser with an external Ne-absorption tube in an alternating magnetic field

Abstract

A single mode He-Ne laser has been frequency stabilised with a relative frequency stability of 10 -'~ and an absolute accuracy of 10-'. The reference frequency is derived from a Ne-absorption cell in an alternating magnetic field. Theoretical analysis and experiments show that this high frequency stability can be achieved only with certain time-dependent functions of the alternating field and with the proper choice of the operating parameters of the laser and absorption tube.