Optical Sensing Device Through Monitoring Cut-Off Wavelength of Asymmetric Transmission

Abstract

In this study, we propose and design a subwavelength optical sensing device to detect material refractive index through metallic structure providing asymmetric transmission behavior. The proposed metallic structure consists of trapezoidal aluminum arrays embedded in Polydimethylsiloxane (PDMS) substrate. We show that a spectral band, where asymmetric transmission takes place shifts depending on the refractive index of the materials which are placed on top of the structure. In this way, optical sensing device can be designed to operate at visible and near infrared regions using the asymmetric transmission effect. The physical concept is based on Wood Rayleigh anomaly. Different sensing applications can be considered to integrate the proposed idea with the optical technologies.