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:
Oct. 06, 1998
Filed:
Oct. 15, 1996
Charles K Asawa, Pacific Palisades, CA (US);
Mike H Asawa, Pacific Palisades, CA (US);
Jane K Asawa, Pacific Palisades, CA (US);
Other;
Abstract
An optical planar waveguide wavelength division demultiplexer for separating multiple wavelengths received in a wavelength division multiplexed communication system is disclosed, with each wavelength launched into a separate output waveguide channel. Wavelength separation is performed by wavelength-selective angular back-reflection from Bragg gratings, which are fabricated into the channel junctions of the planar germania-enriched silica waveguide by applying short wavelength light past a mask. A second Bragg reflection, reflecting the same wavelength as the first Bragg grating, is introduced into each output channel circuit, in order to attenuate residual backscattered light at non-desired wavelengths. The Bragg grating is extended beyond the channel junctions into the merged channel for greater reflectivity, if required, for the double Bragg grating geometry. Two planar waveguide geometries are shown: An asymmetric geometry where the output channels merge on either side of a straight input channel, and a symmetric geometry where the input and output channels merge symmetrically with respect to an arbitrary center line.