Digital holography at 10.6 μm

Digital holography (DH) at the 10.6 mum of a CO2 laser can be successfully used to reconstruct numerically intensity and phase of the object wavefield. A Mach-Zehnder interferometer with a pyroelectric type optoelectronic sensor array is used to record digital off axis Fresnel holograms of an extended object. We demonstrate that, although the pyro-camera spatial resolution is much less than that of typical detectors working in the visible spectral region, good intensity and phase reconstructions are provided. The principle of Fresnel reconstruction in DH is described and results of reconstruction process for object size of the order of 700 mum are presented and discussed. Furthermore we propose a method to accurately determine the wave vector components of the reference wavefield for off axis DH set-up to obtain correct phase wavefield reconstruction. (C) 2002 Elsevier Science B.V. All rights reserved.