Ge-on-Si waveguides for sensing in the molecular fingerprint regime

Griskeviciute, U., Millar, R. W. , Gallacher, K. , Valente, J. and Paul, D. J. (2020) Ge-on-Si waveguides for sensing in the molecular fingerprint regime. Optics Express, 28(4), pp. 5749-5757. (doi: 10.1364/OE.382356)

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Low loss, single mode, Ge-on-Si rib waveguides are used to demonstrated optical sensing in the molecular fingerprint region of the mid-infrared spectrum. Sensing is carried out using two spin-coated films, with strong absorption in the mid-infrared. These films are used to calibrate the modal overlap with an analyte, and therefore experimentally demonstrate the potential for Ge-on-Si waveguides for mid-infrared sensing applications. The results are compared to Fourier transform infrared spectroscopy measurements. The advantage of waveguide spectroscopy is demonstrated in terms of the increased optical interaction, and a new multi-path length approach is demonstrated to improve the dynamic range, which is not possible with conventional FTIR or attenuated total reflection (ATR) measurements. These results highlight the potential for Ge-on-Si as an integrated sensing platform for healthcare, pollution monitoring and defence applications.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Millar, Dr Ross and Hawley, Mrs Ugne and Paul, Professor Douglas and Gallacher, Dr Kevin and Valente, Dr Joao
Authors: Griskeviciute, U., Millar, R. W., Gallacher, K., Valente, J., and Paul, D. J.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Optics Express
Publisher:Optical Society of America
ISSN (Online):1094-4087
Published Online:14 February 2020
Copyright Holders:Copyright © 2020 The Authors
First Published:First published in Optics Express 28(4):5749-5757
Publisher Policy:Reproduced under a Creative Commons License

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
171911Engineering Quantum Technology Systems on a Silicon PlatformDouglas PaulEngineering and Physical Sciences Research Council (EPSRC)EP/N003225/1ENG - Electronics & Nanoscale Engineering