Kinetics of emission spectra of multimode lasers and its influence on the sensitivity of intracavity laser spectroscopy

Theoretical and experimental investigations were made of fluctuations of the intensity of radiation representing individual modes of a multimode laser. A model was developed for the nonlinear interaction of modes and numerical calculations were made of the kinetics of lasing allowing both for the interaction between the modes and for quantum fluctuations. It was found that the only factor governing the sensitivity of intracavity spectroscopy is the duration of lasing in each mode, which in turn may be governed either by quantum fluctuations or by the mode interactions. The optimal laser radiation power ensuring maximum sensitivity of intracavity spectroscopy was found. A satisfactory agreement was obtained beween experimental and calculated results.