Abstract:
A method of holographic wavefront sensing is disclosed. The method comprises: receiving (302) a light beam (202) on a transparent, flat substrate (102), provided with a lattice (104) of opaque dots (106); detecting (304) by an image sensor (108) an interference pattern (204) formed by diffracted light, being scattered by the opaque dots (106), and undiffracted light of the light beam (202); processing (306) the detected interference pattern (204) to digitally reconstruct a representation of a displaced lattice (206), which would form the interference pattern (204) on the image sensor (108) upon receiving the light with a known wavefront; and comparing (308) the representation of the displaced lattice (206) to a known representation of the lattice (104) to determine a representation of the wavefront form of the received light beam (202). An apparatus (100) and a system (400) for holographic wavefront sensing are also disclosed.
Abstract:
An apparatus, associated method, use and computer program product for performing in-line lens-free digital holography of an object (4), the apparatus comprising: - a single point light source (2) adapted for emitting coherent light; - an image sensing device (5) adapted for recording interference patterns resulting from interference from light waves directly originating from the point light source and object light waves (7) originating from scattering or reflection of light waves from the point light source by the object (4), the image sensing device comprising a plurality of pixels (50); wherein the image sensing device is adapted for receiving and recording, at the same moment in time, a plurality of interference patterns by a respective plurality of disjoint subsets of pixels. Advantageously, the source is a broadband light source, and each said subsets of pixels is registered with a colour filter selected among a set (e.g. 4) of narrow band, non-overlapping wavelength filters (I,II,III,IV).