Browse Prior Art Database

Phase Plate Lens for a Multiple Image Lens System

IP.com Disclosure Number: IPCOM000094081D
Original Publication Date: 1966-May-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Genovese, FC: AUTHOR [+3]

Abstract

This phase plate lens is useful for a multiple image lens system, is used in the semiconductor photographic reproduction of images for subsequent diffusion or etching operations.

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Phase Plate Lens for a Multiple Image Lens System

This phase plate lens is useful for a multiple image lens system, is used in the semiconductor photographic reproduction of images for subsequent diffusion or etching operations.

The phase plate lens, drawing A, consists of a plurality of concentric grooves formed about a central recessed portion 10 thus giving the appearance of a Bull's Eye type configuration. This type lens is the same as a zone plate lens except that alternate regions are phase advanced or retailed by 180 degrees instead of being obstructed in a zone plate lens by opaque regions.

Hence, an individual phase plate lens is made by replacing the opaque areas of a zone plate lens by a transparent medium of the correct thickness to shift the phase of the monochromatic light source that is used by 180. This is done by adding a film of transparent material by depositing techniques or in the alternative by removing from the surface of the lens certain selected areas by etching techniques. The result is that a lens is constructed in which alternate areas or zones of the lens are etched or raised by a depth proportional to the wavelength of the light source which is equivalent to shift the phase of the transmitted light by 180 degrees. In this manner, the areas and light intensity achieved by using a phase plate lens is of the order of twice the areas ad light intensity achieved using a zone plate lens. Therefore, there is a fourfold decrease in exposure...