Near Total Resonant Light Absorption in a Graphene Monolayer at Multiple Tunable Wavelengths with Multilayer Structures

Abstract

Graphene could be potentially important for a broad range of photonic and optoelectronic applications. For such graphene-based applications it is critical to enhance the absorption of light in graphene monolayers in order to achieve near total absorption. Several structures have been proposed to enhance light absorption in graphene at visible and infrared wavelengths such as one-dimensional Fabry-Perot cavity structures, and photonic crystal slabs. Fabry-Perot cavity structures, which employ periodic Bragg mirrors, can lead to near total light absorption on resonance. However, such structures cannot achieve near complete absorption in graphene at multiple closely-spaced tunable wavelengths, which is potentially important for applications requiring multispectral light detection. In this thesis, we consider a one-dimensional system for enhancing the absorption in a graphene monolayer at multiple tunable wavelengths. The graphene monolayer is sandwiched between two aperiodic multilayer structures composed of alternating layers of silicon and silica. The structure is deposited on a silica substrate. We show that such a system can achieve near total resonant light absorption in graphene at multiple tunable wavelengths.