Semiclassical treatment of the optical maser

Using the semiclassical theory of radiation, the steady-state operation of the optical maser oscillator is studied in the case where a single "cavity" mode is excited. On introducing certain simplifying assumptions, a straightforward calculation leads to concise results for the frequency and amplitude of the field oscillations. These results are either well known or readily interpreted. For example, a frequency pulling effect is predicted which corresponds to the Bloch-Siegert shift, or alternatively is understandable as due to the Stark effect.