Interferometric measurements and analysis with applications in elastohydrodynamic experiments

Abstract: Section A in this thesis is dedicated to measurements of lubricant films separating rotating surfaces in elastohydrodynamic experiments. Two specially designed interferometry-based methods are presented. A method to compensate for measurement errors due to the pressure dependence of the refractive index of the lubricant is proposed. Automatic fringe analysis is treated in section B. A noise-insensitive two-dimensional phase unwrapping method is presented, together with a pre-processing method that estimates local fringe density and direction. A method to determine a continuous phase from interferometric measurements, where no intermediate modulo-mapped phase data is produced and thus no phase unwrapping is necessary, is proposed.