Frequency-locking and single-mode operation of a CW dye ring laser near the atomic lines of a gas discharge

Assuming lens action by the gas discharge we can theoretically substantiate the features of a CW dye ring laser locked near an atomic transition; features such as the dependence of the laser bandwidth and the frequency separation from the atomic transition on the spacing of the curved mirrors and the occurrence of an asymmetric profile for the laser output. The values experimentally obtained for the 588.2 nm absorption line in a neon discharge show good agreement with those predicted by theory. In the strong-locking regime bistable, unidirectional, single-mode operation occurs. This behaviour could be utilized to obtain sharp frequency marks in the tuning range of a CW dye ring laser.