Surface plasmon excitation as a tool to find optimal grating parameters for quantum well infrared photodetectors

Abstract

A simple transmission measurement technique in order to find the optimal metallic grating parameters for quantum well infrared photodetectors is presented. The excitation of localized surface plasmons in the metallic gratings results in dips in the transmission and it allows us to find an effective range of operating wavelengths for a particular grating period for utilizing the first order diffracted waves as well as to find an optimal grating period when utilizes the non-propagating plasmonic mode. The enhancement in absorption in the quantum well absorber layer due to the effect of grating is also studied theoretically. This simple transmission measurement technique is believed to be a promising tool for finding optimal grating parameters for the quantum well infrared photodetectors without detector fabrication and low temperature characterization.