Digital holography for quantitative phase-contrast imaging.

We present a new application of digital holography for phase-contrast imaging and optical metrology. This holographic imaging technique uses a CCD camera for recording of a digital Fresnel off-axis hologram and a numerical method for hologram reconstruction. The method simultaneously provides an amplitude-contrast image and a quantitative phase-contrast image. An application to surface profilometry is presented and shows excellent agreement with contact-stylus probe measurements.