Alignment Properties of Finite-Size and Non-Spherical Optical Microresonators

We investigate theoretically and numerically how Fabry-Perot microresonators with finite mirror size or non-spherical mirrors behave under transverse misalignment. An efficient operator method is developed to model mode mixing and to calculate clipping losses as the resonator mirrors are displaced. We observe an intricate structure of mode resonances with significant impact on losses and on mode profiles depending on mirror shapes. For example, we find mode resonances with reduced losses for finite-size spherical mirrors but generally enhanced losses for Gaussian-shaped mirrors.