Enhancement of Light Absorption in Plasmonic Based Photodetector with Double Nanograting Structure

Abstract

\n This era of high speed photonic system demand photodetectors to have large bandwidth, gain and improved light enhancement competence. Amongst the different light absorption enhancement methods being researched by the investigators, plasmonic has acquired increased attention in the last decades. Although single layer plasmonic supported metal semiconductor metal photodetector (MSM-PD) has been explored for higher light absorption efficiency, but exploration for double-layer structure is lacking in the literature. This paper presents the performance of plasmonic based photodetectors (PDs) with double layer of nanogratings optimized at wavelength of 1.4 µm for night vision applications. Proposed design of plasmonic supported photodetector with double nanograting reports Quenching factor (QF) of 92.14% and provides enhancement in light with the optimized height of subwavelength aperture (SWA) at 60 nm. This can be credited to fact that both top and bottom layer of grating contributes to light trapping.