Sensitivity adjustable contouring by digital holography and a virtual reference wavefront

Abstract

A new method of contouring using digital holography and a virtual reference wavefront is reported. In this method, an object wave is first recorded and then digitally reconstructed. At the same time, a reference wave is digitally introduced to interfere with the reconstructed object wave to form a contour pattern. Since the form or curvature of the reference wave can be arbitrarily designed and artificially generated by a computer, the contouring sensitivity (the depth interval) can be easily adjusted for different purpose. The effectiveness of this method has been verified by computer simulations with both the conventional off-axis hologram and the phase-shifting hologram. The simplicity of optical setup and the unique ability of changing contouring sensitivity in this technique make it attractive potential in practical measurements.