A sensitive optical probe for surface topography based on an optimized astigmatic method

Surface topography is required for many kinds of industrial products, and its applications keep increasing, making the need for adequate control of surfaces and an understanding of surface topography measurements more important than ever. In this paper, we presented a sensitive and cost-effective optical probe for surface topography. An astigmatic method used in the optical probe was optimized for submicron/nanometer resolution and monotonic characterization of focus error signal (FES). A home-made system based on this optical probe was also presented, and the measurement results of surface topography indicate great potential of applications in many industrial fields.