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. 05, 1988
Filed:
Jul. 21, 1986
Donald H McMahon, Carlisle, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
Bulk optic echelon gratings suitable for use in multi/demultiplexing optical signals carried on sets of optical fibers. The gratings can be either reflective or transmissive and may be either curved with self-focusing properties or planar requiring the use of auxiliary collimating optics. All versions have the property of being simultaneously blazed at at least two different wavelengths whose ratio is in the range between 0.8 and 0.9. This property of the gratings enables their operation over preferred multiple wavelength bands using a limited set of fibers which are fixed in place. Preferred wavelengths at which the gratings are simultaneously blazed include 1.3 and 1.55 micrometers. Devices incorporating the gratings can be used singly or in groups in inverted tree arrangements for tandem or hierarchical multiplexing purposes.