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:
Apr. 11, 1989
Filed:
Oct. 16, 1987
James F Biegen, Middletown, CT (US);
Zygo Corporation, Middlefield, CT (US);
Abstract
An improved system for testing a full reflectivity range of optical surfaces employs an improved Fizeau spherical or plano wavefront interferometer comprising a laser source (2) and an optical element (18) located in the wavefront (16) having a reference surface (20) everywhere normal to the wavefront (16) which has a partially reflective, partially absorbtive, and partially transmissive beamsplitting coating (19) applied to the plano or spherical reference surface (20) and having a transmittance such that there will be only two beam interference and the contrast of the two beam interference fringes between the reflected reference wavefront (25R) and the reflected test wavefront (25T) will be substantially equalized at the two extremes of the test surface (28) reflectivity.