Manipulations of Wavefront Propagation: Useful Methods and Applications for Interferometric Measurements and Scanning.

Phase measurements obtained by high-coherence interferometry are restricted by the 2 ambiguity, to height differences smaller than /2. A further restriction in most interferometric systems is for focusing the system on the measured object. We present two methods that overcome these restrictions.

Wavefront reconstruction by spatial-phase-shift imaging interferometry.

Common-path imaging interferometers offer some advantages over other interferometers, such as insensitivity to vibrations and the ability to be attached to any optical system to analyze an imaged wavefront. We introduce the spatial-phase-shift imaging interferometry technique for surface measurements and wavefront analysis in which different parts of the wavefront undergo certain manipulations in a certain plane along the optical axis. These manipulations replace the reference-beam phase shifting of existing interferometry methods.

Spatial phase-shift interferometry--a wavefront analysis technique for three-dimensional topometry.

We describe a new wavefront analysis method, in which certain wavefront manipulations are applied to a spatially defined area in a certain plane along the optical axis. These manipulations replace the reference-beam phase shifting of existing methods, making this method a spatial phase-shift interferometry method. We demonstrate the system's dependence on a defined spatial Airy number, which is the ratio of the characteristic dimension of the manipulated area and the Airy disk diameter of the optical system.