Observation of polarization-dependent optical Tamm states in heterostructures containing hyperbolic metamaterials in the near-infrared region

Abstract

In the heterostructure composed of metal and one-dimensional photonic crystal (1DPC), the optical Tamm state (OTS) can be excited directly without the coupling of prism or grating, but it is strongly dependent on the photonic band gap (PBG) of the 1DPC. In particular, the PBG of the all-dielectric 1DPC as well as the corresponding OTSs shift toward shorter wavelengths for both transverse magnetic (TM) and transverse electric (TE) polarizations as the angle of incidence increases, making it impossible to achieve a high-performance polarization selection. In a heterostructure consisting of a silver layer and an ITO-based one-dimensional photonic hypercrystal (1DPHC), we experimentally observe for the first time that the OTSs are red-shifted for TM polarization and blue-shifted for TE polarization with increasing incident angle. The ITO-based 1DPHC possesses a large red-shifted PBG in the near-infrared region, which guarantees the full excitation of the OTSs at different angles. Our work provides a potential direction for improving the sensitivity, polarization selection and operating angle range of the Tamm sensor.