The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 1998
Filed:
Feb. 07, 1996
Steven Ebstein, Newton, MA (US);
Lexitek, Inc., Wellesley, MA (US);
Abstract
Diffractive optical elements (DOEs) consisting of a sandwich of two materials are described with an interfacial surface whose relief height impresses the desired optical phase. The two materials have nearly matched indices of refraction, so the interfacial surface has a profile that varies by many wavelengths and is easily fabricated. The materials are chosen such that the refractive index difference and dispersion obey a matching condition that renders the optical path difference (OPD) across the element constant across a broad band of wavelengths. This achromatizes the DOE in that the diffraction efficiency is independent of wavelength. This achromatic property and the fabrication ease allowed by the nearly index matched (NIM) materials enables hybrid refractive-diffractive elements to be fabricated by molding processes for broadband applications.