Diffraction characteristics of concentric circular metal grating operating at terahertz regime

Xiaofeng Li, Siu Fung Yu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)

Abstract

A rigorous coupled-wave model is proposed to simulate the diffraction characteristics of a concentric circular metal grating (CCMG) for an incident transverse-magnetic (TM) wave at terahertz frequency. An infinite series of spatial harmonic Floquet waves with Hankel distribution is used to describe the high-order diffraction waves. The corresponding coupled-wave equations are then solved numerically by transfer matrix method. It can be shown that the proposed model is unconditionally stable. Furthermore, fast convergent rate can be achieved with only a few orders of diffraction waves taken into consideration. Results show that although a lot of high-order diffraction waves could be excited by the metal grating, only a few of them will remain propagating after the diffraction. It is found that if the wavelength of the incident TM wave is relatively long, the reflection spectrum will be dominated by the 0th-order diffraction wave. The effects of incident angle and grating duty cycle on the propagating modal number and diffraction efficiency are also investigated.
Original languageEnglish
Article number5427248
Pages (from-to)898-905
Number of pages8
JournalIEEE Journal of Quantum Electronics
Volume46
Issue number6
DOIs
Publication statusPublished - 19 Mar 2010
Externally publishedYes

Keywords

  • Circular metal grating
  • Coupled-wave model
  • Diffraction waves
  • Terahertz

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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