Showing papers on "Zone plate published in 1971"

Zone plate optics monolithically integrated with photoelectric elements

Abstract: Zone plate optics is monolithically integrated with a phase filter and a photoelectric element to provide an image conforming to the shape of the photoelectric element Saving of space at optimized light input is achieved by multiple reflections of light beam or by close packing of optical elements in a two dimensional matrix of hexagonal symmetry

Recorder with zone plate scanner

Abstract: A zone plate scanner for wide bandwidth laser recorders utilizing a rotating disc having pairs of peripheral windows, each containing a zone plate, one set of windows in each pair being spaced circumferentially at a constant radius, and a second set being similarly spaced circumferentially but each having a different radius. The spacing changes the grating frequency for each pair and encodes each track on a moving film in a manner which eliminates interference in close spacing and reduces the criticality of readout equipment.

Design and Preliminary Test of an Underwater Viewing System using Sound Holography

Abstract: An underwater viewing system based on holographic principles has been presented at the Second International Meeting on Acoustic Holography.1 Since the conceptual aspects have already been outlined in the previous paper,1 the design and construction criteria for the implementation of such a system are emphasized here.

Design, production and performance of circular fresnel zone plates.

Abstract: This paper describes the design and the spark-erosion production technique for circular Fresnel zone plates with focal lengths between 3 m and 40 m when illuminated by a HeNe laser emitting light at 633 nm. Their image pattern is theoretically investigated by modifying Lommel’s original approach to the problem in order to determine the effects of a decentered beam, varying zone numbers and a range of gaussian illumination parameters. The equations derived are evaluated and their results graphically illustrated. The theoretical predictions are experimentally verified for three typical zone plates. The results are discussed with particular regard to their bearing upon the use of zone plates as the optical reference elements in an alignment system at present in an advanced stage of development at the U.K. National Physical Laboratory.

Phase filter combination with lens optics

Abstract: A zonal phase filter is combined with a lens optics to produce a circular image of a point light source. Integration of the phase filter with zone plate optics is described.