Agere Systems Guardian Corp.

Agere Systems Inc.

Triquint Technology Holding Co.

Glen Robert Kowach

David Wilfred Johnson

David Alan Ackerman

Paul Joseph Lemaire

Lynn Frances Schneemeyer

Debra Anne Fleming

Paul S Westbrook

Benjamin John Eggleton

Thomas L Koch

Arturo Hale

Robert Louis Hartman

Charles D Brandle, Jr

Jon W Engelberth

Suhas Dattatreya Bhandarkar

Richard Bendicks Bylsma

Steven Herbert Simon

Malcolm Ellis Lines

Sharad Ramanathan

Henry Du

Ashish Ahuja

Deok-Yang Kim

Silica sol techniques are described for making thick silica or silica based films useful for planar optical waveguides. The process involves coating of a colloidal silica sol onto a substrate, drying the sol, and consolidating the dried sol to form the planar waveguide. Coating is performed in a simple operation, either by dipping, or preferably by spin coating. In a preferred embodiment the substrate is coated with a wetting agent prior to spin coating. It is found that the wetting agent substantially improves the thickness uniformity of the layer. Thick waveguide layers may be produced by repeating the coating process one or more times to produce a layer with the desired thickness. Buried waveguides are produced by forming a doped core layer, patterning the doped core layer and using the coating technique of the invention to form the cladding material.

Manufacture of planar waveguides using sol-gel techniques

The thermo-optic behavior of an optical path over a range of temperatures is controlled by determining a figure of merit (FoM) for the optical path and including in the path a body of NaBi(MoWO)crystalline material that enables the conditions specified by the FOM to be satisfied. The NaBi(MoWO)crystalline material is highly transparent at a wavelength of radiation propagating in the path, and has a coefficient of thermal expansion (CTE) and a refractive index n such that the CTE and dn/dT of the etalon compensate one another so as to perform frequency discrimination that is essentially temperature insensitive over the range &#x394;T. The NaBi(MoWO)crystalline material exhibits temperature independent transmission characteristics at about room temperature and at a wavelength of about 1550 nm.

Optical device with a temperature insensitive optical pathlength

The thermo-optic behavior of an optical path over a range of temperatures &Dgr;T is controlled by determining a figure-of-merit (FOM) for the optical path and including in the path a body of crystalline material that enables the conditions specified by the FOM to be satisfied. The crystalline material is highly transparent at a wavelength &lgr; of radiation propagating in the path, and it has a coefficient of thermal expansion (CTE) and a refractive index n such that the CTE and dn/dT are mutually adapted to satisfy the FOM over the range &Dgr;T. In one embodiment, the CTE and dn/dT of an etalon compensate one another so as to perform frequency discrimination that is essentially temperature insensitive over the range &Dgr;T. In a preferred embodiment of the optical etalon the crystalline material comprises LiCaAlF .

Using crystalline materials to control the thermo-optic behavior of an optical path

In accordance with the invention, an optical waveguide comprising a longitudinally extending core housing an optical grating and a cladding layer peripherally surrounding the core, is provided with an outer surface of the cladding layer having one or more perturbations. Each perturbation has a height with respect to the core that varies by at least 0.1 times a Bragg wavelength of the grating over the surface of the perturbation and covers an extent of the outer surface whose linear dimensions are less than 1 cm. The perturbations suppress cladding mode spectra and reduce short wavelength cladding mode loss.

Optical waveguide gratings having roughened cladding for reduced short wavelength cladding mode loss

Ceramic monoliths are described which exhibit tunable coefficients of thermal expansion from about &minus;5 to &minus;11&times;10 &deg; C. near ambient temperatures. These two-phase ceramics, which are fabricated, for example, by reactive sintering of WO and ZrO , consists of a matrix of ZrW O with inclusions of ZrO having diameters less than 10 &mgr;m. Additives may increase the density of the monoliths to greater than 98% of the calculated density. Green body densities, pre-sintered particle size distribution, sintering atmosphere, microstructure, and mechanical properties are discussed. These ceramics may be used as substrates for thermally compensating fiber Bragg gratings.

Process for making isotropic negative thermal expansion ceramics

Ceramic monoliths are described which exhibit tunable coefficients of thermal expansion from about &minus;5 to &minus;11&times;10,&deg; C.,near ambient temperatures. These two-phase ceramics, which are fabricated, for example, by reactive sintering of WO,and ZrO,, consists of a matrix of ZrW,O,with inclusions of ZrO,having diameters less than 10 &mgr;m. Additives may increase the density of the monoliths to greater than 98% of the calculated density. Green body densities, pre-sintered particle size distribution, sintering atmosphere, microstructure, and mechanical properties are discussed. These ceramics may be used as substrates for thermally compensating fiber Bragg gratings.

Isotropic negative thermal expansion cermics and process for making

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Fanwood, NJ, United States of America

Glen Robert Kowach