All-optical mode switching with a graphene-buried polymer waveguide directional coupler

Lianzhong JIANG; Kin Seng CHIANG

doi:10.1364/OL.458204

Author(s)

Related Research Unit(s)

Department of Electrical Engineering

Detail(s)

Original language	English
Pages (from-to)	2414-2417
Journal / Publication	Optics Letters
Volume	47
Issue number	10
Online published	3 May 2022
Publication status	Published - 15 May 2022

Link(s)

DOI	DOI https://doi.org/10.1364/OL.458204 Final Published version
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Attachment(s)	Documents 98803117.pdf Post-print, 548 KB, PDF Publisher's Copyright Statement © 2022 Optica Publishing Group. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.
Link to Scopus	https://www.scopus.com/record/display.uri?eid=2-s2.0-85130016635&origin=recordpage
Permanent Link	https://scholars.cityu.edu.hk/en/publications/publication(f3dcc58c-bb03-486d-9aba-82890dc108dc).html

Abstract

We demonstrate all-optical mode switching with a graphene-buried polymer waveguide asymmetric directional coupler (DC) by using the photothermal effect of graphene, where TE-polarized pump light and TM-polarized signal light are employed to maximize pump absorption and minimize graphene-induced signal loss. Our experimental device, which uses a graphene length of 6.2 mm, shows a pump absorption of 3.4 dB (at 980 nm) and a graphene-induced signal loss of 0.1 dB. The device can spatially switch between the fundamental mode and the higher-order mode with extinction ratios larger than 10 dB (at 1580 nm) and switching times slightly shorter than 1 ms at a pump power of 36.6 mW. Graphene-buried polymer waveguides offer many new possibilities for the realization of low-power all-optical control devices.