Introduction to the Sub-pixel Spatial Resolution Interferometry Process

In this paper we describe a method called "Sub-Pixel Spatial Resolution Interferometry" used to increase the spatial resolution of interferometric measurements of precision optical surfaces. In this process, multiple interferometric measurements are made as the optic under test (or the CCD array)in shifted at sub-pixel increments. The measurements are then combined to construct a measurement with higher spatial resolution than the original measurements. The process will be described and initial results obtained using this process with a commercially available Fizeau interferometer will be presented.