Demonstration of the Multimaterial Coating Concept to Reduce Thermal Noise in Gravitational-Wave Detectors

S.C. Tait, J. Steinlechner*, M.M. Kinley-Hanlon, P.G. Murray, J. Hough, G. McGhee, F. Pein, S. Rowan, R. Schnabel, C. Smith, L. Terkowski, I.W. Martin

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Thermal noise associated with the mechanical loss of current highly reflective mirror coatings is a critical limit to the sensitivity of gravitational-wave detectors. Several alternative coating materials show potential for reducing thermal noise, but cannot be used due to their high optical absorption. Multimaterial coatings have been proposed to enable the use of such materials to reduce thermal noise while minimizing their impact on the total absorption of the mirror coating. Here we present experimental verification of the multimaterial concept, by integrating aSi into a highly reflective SiO2 and Ta2O5 multilayer coating. We show a significant thermal noise improvement and demonstrate consistent optical and mechanical performance. The multimaterial coating survives the heat treatment required to minimize the absorption of the aSi layers, with no adverse effects from the different thermomechanical properties of the three materials.

Original languageEnglish
Article number011102
Number of pages7
JournalPhysical Review Letters
Issue number1
Publication statusPublished - 1 Jul 2020
Externally publishedYes



Cite this