Plasmonic Tamm states in insulator–metal–insulator waveguides

Abstract

Plasmonic Tamm states configuration is proposed for field enhancement in an insulator–metal–insulator (IMI) Bragg reflector by periodic modulation of the dielectrics surrounding the metal core. Finite-difference time-domain simulation is carried out for the structure optimization and the dispersion relation of plasmonic Tamm states. In the metal–Bragg reflector interface, 2 orders of magnitude of electromagnetic field intensity enhancement and 4 orders of magnitude of decay rate enhancement are obtained. Besides the field enhancement, there are two plasmonic Tamm states that are related to the even and odd modes in the IMI waveguide. The two plasmonic Tamm states show large difference in the reflection spectra. The proposed structure would provide promising potential for electromagnetic nanofocusing and nanosensing.