Super resolution technique for digital holography: Experimental Validation

Recently Super Resolution (SR) has been proposed as a way to improve the lateral resolution of Digital Holography (DH). In fact the relatively large dimensions of camera pixels severely limit this otherwise very interesting technique. However combining Super Resolution and Digital Holography is not easy. In fact Super Resolution requires acquiring several images shifted of a non-integer fraction of a pixel; moreover it has been shown that an accurate positioning is a key factor to obtain high quality super-resolved digital holograms. Thus either a closed loop controlled PZT translator or an auxiliary measurement technique has to be used. This work try to asses the performance of super-resolved Digital Holography by comparing the frequency content of super-resolved and standard holograms of the same object. The limits (in term of magnification) of the technique are also inspected by analyzing how the frequency content depends on magnification.