title: Subwavelength Gold Grating as Polarizers Integrated with InP-Based InGaAs Sensors.
abstract: There are currently growing needs for polarimetric imaging in infrared wavelengths for broad applications in bioscience, communications and agriculture, etc. Subwavelength metallic gratings are capable of separating transverse magnetic (TM) mode from transverse electric (TE) mode to form polarized light, offering a reliable approach for the detection in polarization way. This work aims to design and fabricate subwavelength gold gratings as polarizers for InP-based InGaAs sensors in 1.0-1.6 μm. The polarization capability of gold gratings on InP substrate with pitches in the range of 200-1200 nm (fixed duty cycle of 0.5) has been systematically studied by both theoretical modeling with a finite-difference time-domain (FDTD) simulator and spectral measurements. Gratings with 200 nm lines/space in 100-nm-thick gold have been fabricated by electron beam lithography (EBL). It was found that subwavelength gold gratings directly integrated on InP cannot be applied as good polarizers, because of the existence of SPP modes in the detection wavelengths. An effective solution has been found by sandwiching the Au/InP bilayer using a 200 nm SiO2 layer, leading to significant improvement in both TM transmission and extinction ratio. At 1.35 μm, the improvement factors are 8 and 10, respectively. Therefore, it is concluded that the Au/SiO2/InP trilayer should be a promising candidate of near-infrared polarizers for the InP-based InGaAs sensors.
authors.affiliation: †State Key Laboratories of Transducer Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.|‡Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.|§University of Chinese Academy of Sciences, Beijing 100039, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: †State Key Laboratories of Transducer Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.|‡Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: †State Key Laboratories of Transducer Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.|‡Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Shao
authors.affiliation: †State Key Laboratories of Transducer Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.|‡Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.affiliation: ∥Nanolithography and Application Research Group, State Key Lab of ASIC and System, School of Information Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Xiaqi
authors.initials: X
authors.lastname: Huang
authors.affiliation: ∥Nanolithography and Application Research Group, State Key Lab of ASIC and System, School of Information Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Jinhai
authors.initials: J
authors.lastname: Shao
authors.affiliation: ∥Nanolithography and Application Research Group, State Key Lab of ASIC and System, School of Information Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Yifang
authors.initials: Y
authors.lastname: Chen
authors.affiliation: †State Key Laboratories of Transducer Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.|‡Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China.
authors.forename: Haimei
authors.initials: H
authors.lastname: Gong
keywords: InP-based InGaAs sensor; cavity mode; polarizer; subwavelength gold grating; surface plasmon polariton