Asymmetric optical transmission of a metallic grating-incorporated Fabry-Perot cavity

In this report, we show a structure of metallic grating-incorporated Fabry-Perot (F-P) cavity demonstrating asymmetric optical transmission (AOT) for all transmission modes. The asymmetric transmission basically arises from asymmetric coupling and decoupling of resonant surface plasmons (SPs) on both sides of the metallic grating with asymmetric media of different indices. Coupling of the SP mode with anti-resonance mode of the F-P cavity in orthogonal directions further optimizes transmission characteristics of the structure for asymmetric transmission. Particularly, a high contrast AOT is achieved by locating the SP resonance position at center of the anti-resonance band of the F-P cavity. Meanwhile, SP resonance modes induced at different interfaces/regions of the cavity structure influence the transmission properties. The AOT structure has no nanoapertures and critical requirements on profile of the grating surfaces for fabrication, and can be adapted to various optical systems.

Automated summary

This report presents a metallic grating-incorporated Fabry-Perot cavity structure that exhibits asymmetric optical transmission (AOT) regardless of transmission modes. The asymmetric transmission is mainly attributed to the asymmetric coupling and decoupling of resonant surface plasmons (SPs) on both sides of the metallic grating with asymmetric media of different refractive indices. Additionally, by coupling the SP mode with the anti-resonance mode of the F-P cavity in orthogonal directions, the transmission characteristics of the structure for asymmetric transmission are further optimized, leading to a high contrast AOT achieved by locating the SP resonance position at the center of the anti-resonance band of the F-P cavity.