Single-frequency lasing aided by a prism selector

Design and performance details for and intracavity selector (IS) prism which functions as an interference device in a laser are presented. The IS operates similarly to a Fabry-Perot interferometer inclined at a specific angle to the resonance axis. Use of a prism instead of an actual interferometer reduces losses by an order of magnitude. A base angle of 80 deg was selected for the prism, which was tested in a Nd glass laser. A selectivity range of 7 nm was obtained as the prism separated adjacent longitudinal modes. The performance was independent of the properties of the cavity resonator and active medium.