High resolution digital holography with two confocal lenses

Based on the research to the resolution of digital holography theoretically and experimentally, a method to realize high lateral resolution digital holographic imaging is experimentally demonstrated. By placing CCD in the rear focal plane of two confocal lenses, their front focal plane as an equivalent digital holographic recording plane can receive more object waves, and the magnifying ratio of the lateral size of the object waves received by CCD is equal to the ratio of focal lengths of two confocal lenses. During the recording of a digital hologram, Shannon sampling criterion can be satisfied by using a spherical reference wave and high resolution CCD (with 4.65×4.65μm ² pixel size). The long working distance belongs to important advantage of the experimental setup. Experimental results show a good agreement with theoretical analysis.