Optical absorption of ion-beam sputtered amorphous silicon coatings

Steinlechner, J., Martin, I. W. , Bassiri, R., Bell, A. , Fejer, M. M., Hough, J. , Markosyan, A., Route, R. K., Rowan, S. and Tornasi, Z. (2016) Optical absorption of ion-beam sputtered amorphous silicon coatings. Physical Review D, 93(6), 062005. (doi: 10.1103/PhysRevD.93.062005)




Low mechanical loss at low temperatures and a high index of refraction should make silicon optimally suited for thermal noise reduction in highly reflective mirror coatings for gravitational wave detectors. However, due to high optical absorption, amorphous silicon (aSi) is unsuitable for being used as a direct high-index coating material to replace tantala. A possible solution is a multimaterial design, which enables exploitation of the excellent mechanical properties of aSi in the lower coating layers. The possible number of aSi layers increases with absorption reduction. In this work, the optimum heat treatment temperature of aSi deposited via ion-beam sputtering was investigated and found to be 450 °C. For this temperature, the absorption after deposition of a single layer of aSi at 1064 nm and 1550 nm was reduced by more than 80%.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Rowan, Professor Sheila and Bell, Dr Angus and Bassiri, Mr Riccardo and Martin, Dr Iain and Steinlechner, Dr Jessica and Tornasi, Mr Zeno and Hough, Professor James
Authors: Steinlechner, J., Martin, I. W., Bassiri, R., Bell, A., Fejer, M. M., Hough, J., Markosyan, A., Route, R. K., Rowan, S., and Tornasi, Z.
College/School:College of Science and Engineering > School of Physics and Astronomy
Research Centre:College of Science and Engineering > School of Physics and Astronomy > Institute for Gravitational Research
Journal Name:Physical Review D
Publisher:American Physical Society
ISSN (Online):1550-2368
Published Online:25 March 2016
Copyright Holders:Copyright © 2016 American Physical Society
First Published:First published in Physical Review D 93(6):062005
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
624341Investigations in Gravitational Radiation / Particle Astrophysics Capital equipmentSheila RowanScience & Technologies Facilities Council (STFC)ST/L000946/1S&E P&A - PHYSICS & ASTRONOMY
643971GraWIToNSheila RowanEuropean Commission (EC)606176S&E P&A - PHYSICS & ASTRONOMY