Calculation of laser modes in an active Perot-Fabry-Interferometer

Abstract

The mode structure and the diffraction losses of a Perot-Fabry-Interferometer filled with an active material are calculated analytically with aGreen's function method. The active material is described by a complex susceptibility. The mode pattern and the diffraction losses derived here are in good agreement with the results of Fox andLi, who obtained the mode pattern and the diffraction losses of the decaying modes of a Perot-Fabry-Interferometer by a machine calculation. Furthermore the case of different dielectric constants between the active material and the outer space and the example of a Perot-Fabry-Interferometer with infinite mirrors are discussed. Throughout the paper only a single mode is treated and it is assumed that the inversion in the active material is constant.