Ultra-narrowband and highly-directional THz thermal emitters based on the bound state in the continuum

Kaili Sun, Zongshan Zhao, Yangjian Cai, Uriel Levy, Zhanghua Han*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

The development of novel and cost-effective THz emitters, with properties superior to current THz sources, is an active and important field of research. In this work, we propose and numerically demonstrate a simple yet effective approach of realizing terahertz sources working in continuous-wave form, by incorporating the new physics of bound state in the continuum (BIC) into thermal emitters. By deliberately designing the structure of slotted disk array made of high-resistivity silicon on top of a low index dielectric buffer layer supported by a conducting substrate, a quasi-BIC mode with ultra-high quality factor (∼104) can be supported. Our results reveal that the structure can operate as an efficient terahertz thermal emitter with near-unity emissivity and ultranarrow bandwidth. For example, an emitter working at 1.3914 THz with an ultranarrow linewidth less than 130 MHz, which is roughly 4 orders of magnitude smaller than that obtained from a metallic metamaterial-based thermal emitter, is shown. In addition to its high monochromaticity, this novel emitter has additional important advantages including high directionality and linear polarization, which makes it a promising candidate as the new generation of THz sources. It holds a great potential for practical applications where high spectral resolving capability is required.

Original languageAmerican English
Pages (from-to)4035-4043
Number of pages9
JournalNanophotonics
Volume10
Issue number16
DOIs
StatePublished - 2 Nov 2021

Bibliographical note

Publisher Copyright:
© 2021 Kaili Sun et al., published by De Gruyter, Berlin/Boston.

Keywords

  • bound state in the continuum
  • terahertz
  • thermal emitter

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