Experimental measurement of photothermal effect in Fabry-Perot cavities

TL;DR

This paper experimentally measures the photothermal effect in high-finesse Fabry-Perot cavities, confirming a theoretical model and highlighting its significance for sensitive interferometric measurements like gravitational wave detection.

Contribution

First experimental validation of the photothermal effect in Fabry-Perot cavities aligning with a recent theoretical model.

Findings

Photothermal effect observed and characterized.

Results agree with theoretical predictions.

Implications for gravitational wave detectors.

Abstract

We report the experimental observation of the photothermal effect. The measurements are performed by modulating the laser power absorbed by the mirrors of two high-finesse Fabry-Perot cavities. The results are very well described by a recently proposed theoretical model [M. Cerdonio, L. Conti, A. Heidmann and M. Pinard, Phys. Rev. D 63 (2001) 082003], confirming the correctness of such calculations. Our observations and quantitative characterization of the photothermal effect demonstrate its critical importance for high sensitivity interferometric displacement measurements, as those necessary for gravitational wave detection.