At&t Bell Laboratories

American Telephone and Telegraph, Co.

Rodney C Kistler

Charles H Henry

Rudolf F Kazarinov

Greg E Blonder

John Milo Poate

Renen Adar

Dale C Jacobson

Yosi Shani

Kenneth J Orlowsky

Aasmund S Sudbo

Albert Polman

Disclosed are planar waveguides comprising substantially polarization-independent Bragg gratings. A preferred embodiment of the invention comprises a Si body with a silica lower cladding layer thereon, and a phosphorus P-doped silica core on the lower cladding. Appropriate periodic recessed features are etched into the core, and phophorus P- and B-doped silica upper cladding is deposited over the core. The dopant concentrations are adjusted such that the refractive index difference between core and upper cladding is small (0.35-1.45.times.10.sup.-2), and such that the flow temperature of the upper cladding material is lower than that of the core material. In another preferred embodiment a thin layer of Si.sub.3 N.sub.x (x.about.4) is conformally deposited over the core after the grating etch, and the upper cladding material is deposited onto the Si.sub.3 N.sub.x layer. Bragg devices according to the invention are advantageously used in Integrated Optical Circuits (IOCs), e.g. in IOCs used in WDM optical communication systems.

Optical waveguide comprising Bragg grating coupling means

Disclosed is apparatus comprising an optically pumped optical gain device that comprises a rare earth (RE)-doped planar waveguide with non-uniform dopant distribution in the core of the waveguide. The RE ions are advantageously distributed such that the ions are concentrated in a core region in which the mode intensity of both signal radiation and pump radiation is relatively high. In preferred embodiments of a single mode planar waveguide according to the invention the RE ions are substantially concentrated in the central core region. A method of making the disclosed apparatus is also disclosed. The method involves implantation of RE ions into the core region.

Apparatus comprising an optical gain device, and method of producing the

An optical device is disclosed which provides wavelength multiplexing/demultiplexing utilizing a plurality of focusing Bragg reflectors. Each Bragg reflector includes a plurality of confocal (i.e., common foci) elliptical grating lines, with the exit/entrance ports of the input/output waveguides located at the foci of the ellipse. By virtue of the elliptical design, the signal propagating outward from the exit port of the input waveguide will be reflected by the appropriate Bragg reflector and focused into the entrance port of the appropriate output waveguide. When each Bragg reflector exhibits a different ellipticity, but shares one common focal point, optical multiplexing/demultiplexing may be achieved. Optical filtering may be achieved when all Bragg reflectors are designed to have common foci.

Optical multiplexer/demultiplexer using focusing Bragg reflectors

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Easton, PA, United States of America

Rodney C Kistler