Resolution analysis of a digital holography system

Although digital holography (DH) has many advantages compared to conventional holography, its resolution is limited due to CCDs or other recording devices. Three factors contribute to this limitation, namely, the pixel averaging effect within the finite detection size of one pixel, a finite CCD aperture size limitation, and the sampling effect due to a finite sampling interval. In this paper, interactions of the three factors on resolution are investigated and presented. The resolution of a DH system can be determined for given parameters of these three factors. The domains dominated by different factors are explained along with their accuracy. As a DH system is space variant, influences of object extent on resolution are also discussed. The resolution performance of in-line and off-axis systems is studied and examples of resolution determination for a practical system are provided.