Sub-pixel spatial resolution interferometry.

摘要

There is a growing need for an increase in the spatial resolution of interferometric surface measurements of precision optics. This research presents a new method for meeting this need. The improvement is necessary because of evolving surface figure and micro-roughness requirements for higher quality optics and optical systems, demand for larger optics, and recent advancements in deterministic polishing. These three topics will be discussed and their relationship to increased spatial resolution will be described. A solution that increases the spatial resolution using interlaced stitching will be presented. In this process, multiple interferometric measurements are made as the optic under test or the CCD array is shifted at sub-pixel increments. The measurements are then combined to construct a measurement with higher spatial resolution than the original measurements. Initial results obtained using this process in conjunction with a commercially available Fizeau interferometer will be presented.