CUED Publications database

Graphene based terahertz phase modulators

Kakenov, N and Ergoktas, MS and Balci, O and Kocabas, C (2018) Graphene based terahertz phase modulators. 2D Materials, 5. ISSN 2053-1583

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Abstract

© 2018 IOP Publishing Ltd. Electrical control of amplitude and phase of terahertz radiation (THz) is the key technological challenge for high resolution and noninvasive THz imaging. The lack of active materials and devices hinders the realization of these imaging systems. Here, we demonstrate an efficient terahertz phase and amplitude modulation using electrically tunable graphene devices. Our device structure consists of electrolyte-gated graphene placed at quarter wavelength distance from a reflecting metallic surface. In this geometry, graphene operates as a tunable impedance surface which yields electrically controlled reflection phase. Terahertz time domain reflection spectroscopy reveals the voltage controlled phase modulation of π and the reflection modulation of 50 dB. To show the promises of our approach, we demonstrate a multipixel phase modulator array which operates as a gradient impedance surface.

Item Type: Article
Uncontrolled Keywords: terahertz phase graphene quarter wave surface electrolyte gating tunable surface impedance gradient phase surface
Subjects: UNSPECIFIED
Divisions: Div B > Solid State Electronics and Nanoscale Science
Depositing User: Cron Job
Date Deposited: 03 May 2018 01:30
Last Modified: 24 Nov 2020 08:38
DOI: 10.1088/2053-1583/aabfaa