Ultrahigh contrast one-way optical transmission through a subwavelength slit

Cataloged from PDF version of article.We computationally demonstrate one-way optical transmission characteristics of a subwavelength slit. We comparatively study the effect in single layer and double layer metallic corrugations. We also investigate the effect of a dielectric spacer layer between double corrugations to control the volumetric coupling of plasmon and optical modes. We computationally show unidirectional transmission behavior with an ultrahigh contrast ratio of 53.4 dB at λ01.56 μm. Volumetric coupling efficiency through the nanoslit strongly depends on the efficient excitation of both the surface plasmon resonance and metal–insulator–metal waveguide modes. We show that the behavior is tunable in a wide spectral range (C) Springer Science+Business Media, LLC 201

Triangular metallic gratings for large absorption enhancement in thin film Si solar cells

Cataloged from PDF version of article.We estimate high optical absorption in silicon thin film photovoltaic devices using triangular corrugations on the back metallic contact. We computationally show 21.9% overall absorptivity in a 100-nm thick silicon layer, exceeding any reported absorptivity using single layer gratings placed on the top or the bottom, considering both transverse electric and transverse magnetic polarizations and a wide spectral range (280 - 1100 nm). We also show that the overall absorptivity of the proposed scheme is relatively insensitive to light polarization and the angle of incidence. We also discuss the implications of potential fabrication process variations on such a device. ©2012 Optical Society of Americ