Tilting nondispersive bands in an empty microcavity

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

Automated summary

This study demonstrates the realization of anticrossing between a cavity mode and a Bragg mode within an empty microcavity, without the need for birefringent materials in the cavity layer. Nondispersive bands are observed within the energy gap due to the specific refractive index distribution of the sample. The TE-TM splitting and XY splitting of DBR mirrors induce the squeezing of cavity modes in momentum space, resulting in tilted and spin-dependent nondispersive bands.