Efficient Fabry-Perot Open Resonator Analysis by the use of a Scattering Matrix Method

In this paper a comparative study of the computational efficiency of two modeling methods applied to the analysis of the plano and double-concave Fabry-Perot open resonators is presented. In both numerical approaches, a scattering matrix method was applied, which allows splitting the analysis of the resonator into several sections, including the one with a spherical mirror, which requires the largest computing resources. Two modeling techniques were utilized to evaluate the scattering matrix of the spherical mirror, namely, the finite element method and free-space Green’s function method. Resonant frequencies and the corresponding field distributions of the selected Gaussian modes were calculated and compared. Good agreement between the methods was achieved; however, the Green’s function method has occurred to be more computationally efficient.