All-Optical Longitudinal Super Resolution
Publication Date: 2004-Nov-24
The IP.com Prior Art Database
A new patented technology proposes an extended depth of focus (longitudinal super resolution) element configured as a phase-affecting, non-diffractive optical element defining a spatially low frequency phase transition that codes the lens aperture. Since this optical element contains low spatial frequencies, it is not sensitive to wavelengths and does not scatter energy towards the outer regions of the field of view. The optical element is a phase element and thus does not require apodization and its energetic efficiency is very high. Since the optical element does not require digital post processing it is adequate for ophthalmic applications. The optical element is a mask constructed out of transparent areas and pi-phase lines (e.g., grid) and/or one or more pi-phase circles that modulate the coherent transfer function of the lens. The positions of those pi-phase transitions are appropriately selected to generate invariance to quadratic phase distortions (that correspond to the effect of getting out of focus) under the operation of auto correlation.