Improving the Accuracy of Microscopic Laser Interferometry System for Precision Surface Measurement by Integrated Scanning Motions

A new technique for improving the accuracy of microscopic laser interferometry system for precision surface measurement is presented. Laser interferometry creates a fringe pattern which contains information about the surface texture of the specimen and the method provides nanometer resolution for height axis of the reconstructed surface. The resolutions of the lateral axes of the surface, however, relies only on optical magnification capability of the measurement system and this often results in poor resolution. This paper presents a new technique to improve the interferometric system resolution in lateral axes. This method is based on an integrated scanning motion of the specimen and the obtained multiple sets of scanned data are processed to improve the lateral axes resolution. Computer simulations show that the proposed method can be an effective approach to improve the resolution in the lateral axes for commonly used laser interferometric system. It provides a new principle for the design of modern laser interferometric measurement instruments.