Studies on digital holography for aspheric surface measurement

Abstract

Digital holography is fast becoming a generalized technique for 3D precision measurement. By numerical reconstruction and propagation of a digital hologram, the optical field from an object and thus the amplitude and phase can be quantitatively reconstructed. The quantitative phase allows determination of the surface topography of the object with nanometer sensitivity. Aspheric lenses are being increasingly used in optical system due to savings in costs and components. However, an aspheric is a complex surface designed using non-linear vi I would like to express my love to my wife and daughter. During past four years, I could not spend too much time with them because of daytime work and night-time research. I even can count the number of weekends that I spent with them. Seeing my daughter's height grow from 82cm to 112cm, during the course of my thesis, I would like to thank again to my wife. Without her support and giving, I could not insist on my Ph.D. work until present. Finally, I would like to acknowledge the financial support from Ngee Ann Polytechnic, Optics and Photonics Society of Singapore and Peking University during my Ph.D. study for international conferences and communications. vii