Donald E. Vandenberg

Quantitative evaluation of optical surfaces by means of an improved Foucault test approach

Foucault knife-edge testing has been the classic qualitative test method for optical surface and wave-front quality measurement for more than one hundred years. We have developed an upgraded quantitative method, using off-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 interlerometry. 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.

Quantitative evaluation of optical surfaces using an improved Foucault test approach

Foucault knife edge testing has been the classic qualitative test method for optical surface and wavefront quality measurement for over one hundred years. We have developed an innovative method, using off the shelf CIigit.a1 microprocessors and a solid state camera, whereby quantitative evaluation of surfaces has been achieved. This paper will describe a method that upgrades the knife edge test from a qualitative test to a precise quantitative evaluation. The hardware is described and results are shown comparing the knife edge test with interferometric measurements.