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:
Sep. 20, 1988
Filed:
Aug. 10, 1987
Carl F Buhrer, Framingham, MA (US);
GTE Laboratories Incorporated, Waltham, MA (US);
Abstract
An achromatic birefringent retardation plate has a quarter wave of linear optical birefringence over a wavelength range centered about a nominal wavelength. The plate includes a combination of two birefringent optical disks in adjacent positions along a light beam axis. Each disk has a linear optical birefringence with a fast axis. The two disks have thicknesses such that, at the nominal wavelength, they have their linear optical birefringence at n and m quarter waves, respectively of the nominal wavelength, where n is an odd integer greater than one and where m is an even integer greater than n. The fast axes of the linear birefrigences of the disks have rotational orientations about the light beam axis whereby the fast axis orientation of the other disk differs from that of one disk by ninety degrees, plus or minus one-half of the angle whose cosine is equal to the ratio of n to m.