Effect of the end mirror curvature error to the contrast of ¥¥a Fabry-Perot based Michelson interferometer
We found that one of the ETMs of the 40m interferometer could be delivered with a curvature error of 5¥% from the nominal radius. The effect of this curvature error to the contrast of a FPMI was investigated by analytical calculation and simulations with FINESSE.
Here is the document.
For the parameter similar to the 40m interferometer with nominal end mirror curvature of 57 m, the contrast defect of the FPMI is given by:
dC = 3.61 x 10-4 dR2 + O3(dR)
and this is dominated by the higher-order modes.
The result was confirmed with simulations on FINESSE.
Relationship between the curvature error and the contrast defect. Red dots show the simulated results. The blue line is the curve for the analytical calculation.