Tilting nondispersive bands in an empty microcavity

Recently, microcavities with anisotropic materials were shown to be able create bands non-zero local Berry curvature. The refractive index of the cavity layer is believed critical in opening an energy gap at tilted Dirac points. In this work, we show that anticrossing between a mode and Bragg can also realized within empty microcavity without any birefringent layer. Nondispersive are observed due particular distribution sample. intrinsic TE-TM splitting XY DBR mirrors induce squeezing modes momentum space, so nondispersive spin-dependent. Our results pave way investigate interesting physical phenomena photonic close or layers.