Multifunction surface measurement system based on focusing optical stylus interference and confocal image

Abstract

In this paper a multifunction surface measurement system based on focusing optical stylus interference and confocal image is researched. This system is designed on the structure of optical interference microscopy and could accomplish two measurement functions of optical stylus scanning measurement and confocal image measurement. Optical path difference would vary with the surface and interference fringe from optical interference microscopy is detected by photo sensor, so optical stylus scanning measurement would be accomplished combining with the X-Y two-dimensional stage. While the reference path of the interference microscope is blocked and the confocal images of the measured surface from CCD is analyzed, confocal imaging measurement would be carried out by the nanometer scanning displacement stage. According to the performance analysis, optical stylus scanning measurement has the measurement range of 50μm and the vertical scanning resolution of 0.005μm, while confocal imaging measurement has the measurement rage of 2mm and the vertical scanning resolution of 1.5μm.