Holography and superresolution

The capability of improving the spatial resolution of imaging systems is usually known as superresolution. Some methods provide improve resolution by playing with the imaging part of the system and without modifying the optical parameters of the imaging lenses. And others act over the geometry, shape and size of sampling pixels in the detection array. The former strategy allows optical superresolution while the latter provide geometrical superresolution. In this contribution, we will review the state of the art in optical superresolution approaches understood as the possibility to overcome the limited resolving power of imaging systems beyond the bounds imposed by Abbe's diffraction theory. The process can be understood as a synthetic aperture generation process in which the limited aperture of the imaging system becomes synthetically expanded allowing a higher cutoff frequency than in the conventional aperture. Special attention will be paid on holographic approaches due to its modern development and practical benefits in many optical fields.