Enhanced optical transmission through a metallic slit covered with a nanostrip and surrounded by corrugations

摘要

We analyzed the optical transmission through a subwavelength slit covered with a nanostrip and surrounded by corrugations in a metal film. Simulations results show that with a nanostrip on top of the slit, the optical transmission efficiency through the slit surrounded by grooves is greatly enhanced for various angles of incidence compared with the structure without the nanostrip. The nanostrip should be thick enough to result in an air nanocavity with high Q value and enhanced transmission efficiency.