Direct coarse sampling of electronic holograms

We describe a series of experiments in order to test a new sampling criterion for wavefront reconstruction from a carrier-frequency signal as obtained in electronic holography. Both a Fourier-transform configuration and a Fresnel-zone form of a digital holographic microscope are described. Direct coarse sampling of holograms with no phase-shifting elements can be used to obtain wavefront reconstruction, with the number of samples required reduced by the ratio f(0)/(2B(s)), where f(0) is the carrier frequency and 2B(s) is the signal bandwidth. (C) 2003 Optical Society of America.