Ellipse fitting for interferometry. Part 2: experimental realization.

Extracting phase and amplitude information from the quadrature signals of an optical interferometer is an essential first step in any measurement. Where these signals are displayed as a Lissajous figure, the primary limitation to accuracy is determined by the goodness-of-fit to the ellipse, which is especially problematic for ellipses with high ellipticity. In a companion paper by Collett and Tee [J. Opt. Soc. Am. A31, 2573 (2014)10.1364/JOSAA.31.002573], we described a novel, linear ellipse fitting method that outperforms all previously published algorithms. Here, we demonstrate the experimental application of this algorithm to several measurement problems of practical interest.