Measurement of thermal noise in multilayer coatings with optimized layer thickness
A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise for a prescribed reflectivity. Coatings with the layer thicknesses optimized to minimize thermal noise could be useful in future generation interferometric gravitational wave detectors where coating thermal noise is expected to limit the sensitivity of the instrument. We present the results of direct measurements of the thermal noise of a standard quarter-wavelength coating and a low noise optimized coating. The measurements indicate a reduction in thermal noise in line with modeling predictions.
Additional Information© 2010 The American Physical Society. Received 7 April 2010; published 3 June 2010. This research was supported by the NSF under Cooperative Agreement PHY-0757058 and the Italian National Institute for Nuclear Physics (INFN) under the Committee-V COAT grant).
Published - Villar2010p10431Phys_Rev_D.pdf