Abstract
Thermal noise of optical components is one of the sensitivity limiting effects in gravitational wave detectors, laser stabilization cavities and many other experiments in basic research. However, current methods for the computation of thermal noise are limited for an application in either infinitely large or symmetrically illuminated masses. I present a general method of computing thermal noise of arbitrary finite-sized masses in optical interferometers. The presented approach generalizes state-of-the-art methods for an application in arbitrary shaped optical elements illuminated by arbitrary spatial light distributions. Furthermore, I show the application of the presented approach to compute thermal noise of maladjusted mirrors in Fabry-Perot interferometers. It is shown that the noise can be reduced by off-axis illumination in the case of thin mirrors.
Highlights
Thermal fluctuations are one of the most dominant noise sources for many interferometric applications like gravitational wave detectors [1] and laser stabilization cavities [2] used for various applications like atom interferometry [3], geodesy [4] and the search for dark matter [5,6]
The calculations are performed for a static optical device, so that the pressures applied to the surfaces are constant
A general method for the computation of thermal noise of arbitrary finitesized masses in optical interferometers is presented. This approach delivers consistent results compared to previous methods for symmetrical optical devices under symmetrical illumination
Summary
Thermal fluctuations are one of the most dominant noise sources for many interferometric applications like gravitational wave detectors [1] and laser stabilization cavities [2] used for various applications like atom interferometry [3], geodesy [4] and the search for dark matter [5,6]. A brief outline of the method follows: The fluctuation-dissipation theorem approach by Levin [7] is based on a virtual oscillating pressure. This pressure is obtained by applying the Maxwell stress tensor σover the entire surface of the optical device under investigation [8]. The total virtual force F0 is equal to the surface integral of the ponderomotive pressure This pressure induces a storage of elastic deformation power inside the optical device Wdef. The pressure leads to a mechanical motion of the whole optical device in general This accelerating motion leads to an error in the computation of Wdef induced by the moments of inertia. The integration is performed over the volume V of the optical device
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
