RESOLUTION STUDIES FOR ELECTRONIC HOLOGRAPHY

The output of an electronic holographic apparatus represents the magni tude and phase of the coherent light reflected from a three-dimensiona l object. The amplitude and phase can be fed into a spatial light modu lator for three-dimensional object reconstruction, and the technique i s thus named electronic holography. Resolution studies of recording an d display devices for electronic holography are presented. The theoret ical analysis for electronic holography is first carried out. Mathemat ically, the additive noise at the exposure of an electronic hologram i s more serious than that at the reconstruction, Simulation is used to verify the,theoretical results, and the resolution requirements for an electronic hologram are deduced. In our simulation, the point source is placed 500 mm in front of the recording device and the reference pl ane wave is tilted at angle pi/4 in the -y direction with the normal t o the recording plane. To discriminate a two-point object with 0.17-mm separation, an 8-bit 256x256 charge injection device with a pixel siz e of 10x10 mu m(2) is necessary. In addition, the additive noise from the ambient light during the exposure or reconstruction of an electron ic hologram should be less than 1/100 of the signal amplitude for a 40 -dB output SNR.