Effect of stress and temperature on the optical properties of silicon nitride membranes at 1550 nm

Fletcher, M., Tait, S. , Steinlechner, J., Martin, I. W. , Bell, A. S. , Hough, J. , Rowan, S. and Schnabel, R. (2018) Effect of stress and temperature on the optical properties of silicon nitride membranes at 1550 nm. Frontiers in Materials, 5, 1. (doi: 10.3389/fmats.2018.00001)

[img]
Preview
Text
154641.pdf - Published Version
Available under License Creative Commons Attribution.

2MB

Abstract

Future gravitational-wave detectors operated at cryogenic temperatures are expected to be limited by thermal noise of the highly reflective mirror coatings. Silicon nitride is an interesting material for such coatings as it shows very low mechanical loss, a property related to low thermal noise, which is known to further decrease under stress. Low optical absorption is also required to maintain the low mirror temperature. Here, we investigate the effect of stress on the optical properties at 1,550 nm of silicon nitride membranes attached to a silicon frame. Our approach includes the measurement of the thermal expansion coefficient and the thermal conductivity of the membranes. The membrane and frame temperatures are varied, and translated into a change in stress using finite element modeling. The resulting product of the optical absorption and thermo-optic coefficient (dn/dT) is measured using photothermal common-path interferometry.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Bell, Dr Angus and Steinlechner, Dr Jessica and Tait, Dr Simon and Rowan, Professor Sheila and Martin, Dr Iain and Hough, Professor James and FLETCHER, MARK
Authors: Fletcher, M., Tait, S., Steinlechner, J., Martin, I. W., Bell, A. S., Hough, J., Rowan, S., and Schnabel, R.
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:Frontiers in Materials
Publisher:Frontiers
ISSN:2296-8016
ISSN (Online):2296-8016
Copyright Holders:Copyright © 2018 The Authors
First Published:First published in Frontiers in Materials 5:1
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
713721Investigations in gravitational radiationSheila RowanScience & Technology Facilities Council (STFC)ST/N005422/1S&E P&A - PHYSICS & ASTRONOMY