Thermal noise and mechanical loss of SiO2/Ta2O5 optical coatings at cryogenic temperatures
Abstract
Mechanical loss of dielectric mirror coatings sets fundamental limits for both gravitational wave detectors and cavity-stabilized optical local oscillators for atomic clocks. Two approaches are used to determine the mechanical loss: ringdown measurements of the coating quality factor and direct measurement of the coating thermal noise. Here we report a systematic study of the mirror thermal noise at 4, 16, 124, and 300 K by operating reference cavities at these temperatures. The directly measured thermal noise is used to extract the mechanical loss for S i O 2 / T a 2 O 5 coatings, which are compared with previously reported values.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 25, 2021
- Source ID
- 10.1364/ol.413758
Entities
People
- Dan G. Matei
- Dhruv Kedar
- Eric Oelker
- F. Riehle
- John M. Robinson
- Jun Ye
- Sebastian Häfner
- Thomas Legero
- Uwe Sterr
- Wei Zhang
- William R. Milner
Organizations
- Defense Advanced Research Projects Agency
- German Research Foundation
- National Institute of Standards and Technology
- National Science Foundation