Metasurface-integrated topological photonic crystal bulk cavity for circularly polarized light and beam shaping

We designed a metasurface-integrated topological photonic crystal that controls the polarization and beam shape of emission. The topological photonic crystal (TPC) bulk cavity works based on band-inversion-induced reflection at the interfaces of different topological structures. Therefore, it can be manufactured with a small-sized cavity, and it is a device capable of sufficiently lasing even at a relatively low threshold. Here, by integrating with dielectric metasurface that can control the phase, amplitude, and polarization of light, we designed and fabricated a TPC cavity that generates circularly polarization and simultaneously beam shape of emission.