Surface Plasmon-Enhanced Absorption in Metal Grating Coupled Terahertz Quantum Well Photodetectors

Author

Guo, Xuemei ; Zhang, Rongting ; Cao, Jun ; Liu, Hongying

Author_Institution

Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China

Volume

48

Issue

9

fYear

2012

Firstpage

1113

Lastpage

1119

Abstract

Effects of surface plasmon polaritons (SPPs) on the absorption efficiencies of metal-grating-coupled terahertz quantum well photodetectors (QWPs) are theoretically investigated. The thin top contact layers of the devices are utilized to support the SPPs, and the metal gratings couple p-polarized incident light into SPP modes. The electric fields related to the SPP modes have large components in the quantum well growth direction and are mostly localized in the multi-quantum-well regions of the terahertz QWPs. The dependences of the resonant absorption behaviors on the device parameters are systematically studied. A maximum value of about 30-fold enhancement of inter-sub-band absorption efficiency is achieved in comparison with that of a traditional 45-degree facet coupling scheme. Our proposed metal-grating-coupled terahertz QWPs is expected to significantly improve the device performance.

Keywords

Absorption; Doping; Electric fields; Gratings; Metals; Quantum well devices; Silicon; Metal grating; quantum well photodetectors; surface plasmon polaritons; terahertz;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/JQE.2012.2202637

Filename

6212298