The University of Southampton
University of Southampton Institutional Repository

High-contrast, GeTe4 waveguides for mid-infrared biomedical sensing applications

High-contrast, GeTe4 waveguides for mid-infrared biomedical sensing applications
High-contrast, GeTe4 waveguides for mid-infrared biomedical sensing applications
The ideal molecular "fingerprint" region for biochemical analysis is dominated by the Mid-IR spectral region from 2µm to 13µm. Realisation of single mode waveguides optimised for evanescent field based sensing is essential to detect analytes of very low concentration using their fingerprint molecular vibrations. Since commonly used silicate glasses do not transmit at wavelengths beyond 3µm and some Mid-IR transmitting glasses such as the fluorides degrade when in contact with water, novel materials are required to cover this range. Germanium telluride is a promising material which has a broad IR transparency in the region of 2µm - 20µm. We demonstrate a "high contrast" (Δn ~ 1), GeTe4 single mode rib waveguide on ZnSe. GeTe4 thin films were deposited on ZnSe substrates by RF sputtering at room temperature. Deposition parameters such as sputtering pressure, power, and argon flow rate were varied to optimise the deposition conditions and to study their effect on the resulting films. The deposited films were amorphous as confirmed by XRD and the average roughness of the films was between 4 and 11nm as measured by AFM. The films transmitted over the full spectral range from 2µm - 20µm as measured by FTIR. Photolithography followed by reactive-ion etching was carried out to etch the film to produce a rib waveguide structure with low surface roughness and vertical sidewalls, using an optimised mixture of CHF3 and O2. Further optical characterization of these waveguides including propagation loss and mode profile will be presented.
Mittal, Vinita
fd5ee9dd-7770-416f-8f47-50ca158b39b0
Wilkinson, J.S.
73483cf3-d9f2-4688-9b09-1c84257884ca
Murugan, G.S.
a867686e-0535-46cc-ad85-c2342086b25b
Mittal, Vinita
fd5ee9dd-7770-416f-8f47-50ca158b39b0
Wilkinson, J.S.
73483cf3-d9f2-4688-9b09-1c84257884ca
Murugan, G.S.
a867686e-0535-46cc-ad85-c2342086b25b

Mittal, Vinita, Wilkinson, J.S. and Murugan, G.S. (2014) High-contrast, GeTe4 waveguides for mid-infrared biomedical sensing applications. Photonics West 2014, San Francisco, United States. 01 - 06 Feb 2014. 10 pp . (doi:10.1117/12.2036972).

Record type: Conference or Workshop Item (Paper)

Abstract

The ideal molecular "fingerprint" region for biochemical analysis is dominated by the Mid-IR spectral region from 2µm to 13µm. Realisation of single mode waveguides optimised for evanescent field based sensing is essential to detect analytes of very low concentration using their fingerprint molecular vibrations. Since commonly used silicate glasses do not transmit at wavelengths beyond 3µm and some Mid-IR transmitting glasses such as the fluorides degrade when in contact with water, novel materials are required to cover this range. Germanium telluride is a promising material which has a broad IR transparency in the region of 2µm - 20µm. We demonstrate a "high contrast" (Δn ~ 1), GeTe4 single mode rib waveguide on ZnSe. GeTe4 thin films were deposited on ZnSe substrates by RF sputtering at room temperature. Deposition parameters such as sputtering pressure, power, and argon flow rate were varied to optimise the deposition conditions and to study their effect on the resulting films. The deposited films were amorphous as confirmed by XRD and the average roughness of the films was between 4 and 11nm as measured by AFM. The films transmitted over the full spectral range from 2µm - 20µm as measured by FTIR. Photolithography followed by reactive-ion etching was carried out to etch the film to produce a rib waveguide structure with low surface roughness and vertical sidewalls, using an optimised mixture of CHF3 and O2. Further optical characterization of these waveguides including propagation loss and mode profile will be presented.

Text
Slabakova SPIE paper Final 300114.pdf - Author's Original
Download (777kB)

More information

e-pub ahead of print date: February 2014
Venue - Dates: Photonics West 2014, San Francisco, United States, 2014-02-01 - 2014-02-06
Organisations: Optoelectronics Research Centre

Identifiers

Local EPrints ID: 363173
URI: http://eprints.soton.ac.uk/id/eprint/363173
PURE UUID: 8c9c4bd8-01b7-4a45-86f5-5f1a9cc80ff6
ORCID for Vinita Mittal: ORCID iD orcid.org/0000-0003-4836-5327
ORCID for J.S. Wilkinson: ORCID iD orcid.org/0000-0003-4712-1697
ORCID for G.S. Murugan: ORCID iD orcid.org/0000-0002-2733-3273

Catalogue record

Date deposited: 20 Mar 2014 17:07
Last modified: 05 Nov 2019 02:10

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×