QUANTITATIVE-EVALUATION OF OPTICAL-SURFACES BY MEANS OF AN IMPROVED FOUCAULT TEST APPROACH

Foucault knife-edge testing has been the classic qualitative test method tor optical surface and wave-front quality measurement for more than one hundred years. We have developed an upgraded quantitative method, using ott-the-shelf digital microprocessors and a solid state camera, to provide white-light evaluation of generalized optical surfaces with the precision and accuracy of computer-aided laser interferometry. We describe a method that upgrades the knife-edge test from a qualitative test to a precise quantitative evaluation. The hardware is described and initial results for some aberrations are shown comparing the knife-edge test with interferometric measurements.