Optical absorption of silicon nitride membranes at 1064 nm and at 1550 nm

Steinlechner, J., Krüger, C., Martin, I. W. , Bell, A. , Hough, J. , Kaufer, H., Rowan, S. , Schnabel, R. and Steinlechner, S. (2017) Optical absorption of silicon nitride membranes at 1064 nm and at 1550 nm. Physical Review D, 96(2), 022007. (doi: 10.1103/PhysRevD.96.022007)

Abstract

Because of a low mechanical loss, thin films made of silicon nitride (Si3N4) are interesting for fundamental research and development in the field of gravitational-wave detection. Si3N4 membranes allow for the characterization of quantum radiation pressure noise (RPN), which will be a limiting noise source in gravitational-wave detectors of the second and third generations. Furthermore, Si3N4 is an interesting material for possible thermal noise reduction in highly reflective mirror coatings. For both applications, the optical absorption of Si3N4 needs to be low. This paper presents absorption measurements on low-stress Si3N4 membranes showing an absorption a factor of 7 lower at 1550 nm than at 1064 nm resulting in an estimated 2 times higher sensitivity in RPN experiments at the higher wavelength and making Si3N4 an interesting material for highly reflective multimaterial mirror coatings at 1550 nm.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Bell, Dr Angus and Steinlechner, Dr Jessica and Rowan, Professor Sheila and Martin, Dr Iain and Steinlechner, Dr Sebastian and Hough, Professor James
• Authors: Steinlechner, J., Krüger, C., Martin, I. W., Bell, A., Hough, J., Kaufer, H., Rowan, S., Schnabel, R., and Steinlechner, S.
• 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: 1550-7998
• ISSN (Online): 1550-2368
• Published Online: 20 July 2017
• Copyright Holders: Copyright © 2017 American Physical Society
• First Published: First published in Physical Review D 96(2):022007
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
59172	1	Optical characterisation of silicon and mirror materials for gravitational astronomy.	Iain Martin	The Royal Society (ROYSOC)	RG110331	S&E P&A - PHYSICS & ASTRONOMY
68376	1	AQUIRE	Stefan Hild	European Commission (EC)	658366	S&E P&A - PHYSICS & ASTRONOMY