Polarization splitting and terahertz oscillations from a single planar Fabry-Perot microcavity

We report the experimental observation of polarization splitting at normal incidence and terahertz oscillations of transmitted light from a single planar microcavity. Optical anisotropy in the SiO2/TiO2-dielectric mirrors leads to two perpendicularly polarized transmission modes. We ascribe the anisotropy to oblique columnar structures in the dielectrics resulting from off-axial growth of the microcavity structure. We apply an up-conversion setup for temporally and spectrally resolved measurements and obtain a corresponding beating of 1.25 THz. Time resolved measurements yield a cavity photon lifetime of 0.65 ps, corresponding to a Q value of 1600. To explain our observations we introduce a Fourier-transform based analytical model. (c) 2006 American Institute of Physics.