Uncertainty in mechanical deformation of a Fabry-Perot cavity due to pressure: towards best mechanical configuration

Abstract

In this paper, a study of the deformation of a refractometer use to achieve a quantum realization of the Pascal is made. First, the propagation of the uncertainty in the measure of pressure due to mechanical deformation was made. Then deformation simulations were made with a cavity designed by the CNAM and whose results are reported in the 18SIB04 Quantumpascal EMPIR project. This step aims to corroborate the methodology used in the simulations. The pressure-normalized relative deformation of this design obtained in 18SIB04 is (-6.390 ± 0.015) × 10-12 Pa-1, the result obtained with our method is (-6.384 ± 0.032) × 10-12 Pa-1, which differs 0.001 times from the value obtained in 18SIB04. Finally, a cylindrical cavity design is presented and simulated obtaining a pressure-normalized relative deformation of (-5.758584 ± 0.00000047) × 10-12 Pa-1, which deforms 0.1 times less.