title: Second-order surface-plasmon assisted responsivity enhancement in germanium nano-photodetectors with bull's eye antennas.
abstract: The enhancement of photo-response in nanometer-scale germanium photodetectors through bull's eye antennas capable of supporting 2nd-order Bloch surface plasmon modes is demonstrated in theory and experiment. A detailed numerical investigation reveals that the presence of surface wave and its constructive interference with the directly incident light are incorporated into the main mechanisms for enhancing transmission through the central nanoaperture. With a grating period of 1500 nm, the area-normalized responsivity can be enhanced up to 3.8 times at 2 V bias for a 780 nm laser. It provides an easier fabrication path for ultra-short wavelength operations especially in devices using optically denser materials.
authors: Fang-Fang
authors: FF
authors: Ren
authors: Wei-Zong
authors: WZ
authors: Xu
authors: Jiandong
authors: J
authors: Ye
authors: Kah-Wee
authors: KW
authors: Ang
authors: Hai
authors: H
authors: Lu
authors: Rong
authors: R
authors: Zhang
authors: Mingbin
authors: M
authors: Yu
authors: Guo-Qiang
authors: GQ
authors: Lo
authors: Hark Hoe
authors: HH
authors: Tan
authors: Chennupati
authors: C
authors: Jagadish