Broad-band spatial light modulation with dual epsilon-near-zero modes

Wen, L., Nan, X., Li, J., Cumming, D. R. S. , Hu, X. and Chen, Q. (2022) Broad-band spatial light modulation with dual epsilon-near-zero modes. Opto-Electronic Advances, 5(6), 200093.

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Abstract

Epsilon-near-zero (ENZ) modes have attracted extensive interests due to its ultrasmall mode volume resulting in extremely strong light-matter interaction (LMI) for active optoelectronic devices. The ENZ modes can be electrically toggled between on and off states with a classic metal-insulator-semiconductor (MIS) configuration and therefore allow access to electro-absorption (E-A) modulation. Relying on the quantum confinement of charge-carriers in the doped semiconductor, the fundamental limitation of achieving high modulation efficiency with MIS junction is that only a nanometer-thin ENZ confinement layer can contribute to the strength of E-A. Further, for the ENZ based spatial light modulation, the requirement of resonant coupling inevitably leads to small absolute modulation depth and limited spectral bandwidth as restricted by the properties of the plasmonic or high-Q resonance systems. In this paper, we proposed and demonstrated a dual-ENZ mode scheme for spatial light modulation with a TCOs/dielectric/silicon nanotrench configuration for the first time. Such a SIS junction can build up two distinct ENZ layers arising from the induced charge-carriers of opposite polarities adjacent to both faces of the dielectric layer. The non-resonant and low-loss deep nanotrench framework allows the free space light to be modulated efficiently via interaction of dual ENZ modes in an elongated manner. Our theoretical and experimental studies reveal that the dual ENZ mode scheme in the SIS configuration leverages the large modulation depth, extended spectral bandwidth together with high speed switching, thus holding great promise for achieving electrically addressed spatial light modulation in near- to mid-infrared regions.

Item Type:Articles
Additional Information:We are grateful for financial supports from National Key Research and Development Program of China (No. 2019YFB2203402), National Natural Science Foundation of China (Nos. 11874029 and 92050108), Guangdong Science and Technology Program International Cooperation Program (Nos. 2021A0505030038), Guangdong Basic and Applied Basic Research Foundation (Nos. 2020B1515020037 and 2022B1515020069), Pearl River Talent Plan Program of Guangdong (No. 2019QN01X120).Fundamental Research Funds for the Central Universities (No. 21621108). DRSC is supported by UK EPSRC Grant EP/T00097X/1.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Cumming, Professor David
Authors: Wen, L., Nan, X., Li, J., Cumming, D. R. S., Hu, X., and Chen, Q.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Opto-Electronic Advances
Publisher:Chinese Academy of Sciences
ISSN:2096-4579
Published Online:27 May 2022
Copyright Holders:Copyright © The Author(s) 2022
First Published:First published in Opto-Electronic Advances 2022
Publisher Policy:Reproduced under a Creative Commons licence

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
171858Integrated Terahertz Sensors - Newton Advanced FellowshipDavid CummingThe Royal Society (ROYSOC)NA140301ENG - Electronics & Nanoscale Engineering
305567QuantIC - The UK Quantum Technoogy Hub in Quantum Enhanced ImagingMiles PadgettEngineering and Physical Sciences Research Council (EPSRC)EP/T00097X/1P&S - Physics & Astronomy