At&t Technologies, Inc.

Bell Telephone Laboratories

At&t Bell Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

Hung C Ling

Man Fei Yan

William R Holland

Warren W Rhodes

Richard Haynes

Gary L Wolk

Heidi M Gordon

Sau-Lan L Ng

An optical waveguide circuit including a nonlinear optical device comprises a metal ground plane (21), a polymer core layer (25) in which optical waves are propagated, and polymer clad layers (22 and 26) on opposite sides of the core layer. The waveguide paths are defined by troughs (23) in one of the clad layers. The nonlinear device is made by electrooptically poling part of the core layer which contains a nonlinear moiety. The clad layers (26 and 22) have a significantly higher conductivity than that of the core layer (25) which improves the efficiency of the electrooptic poling.

Nonlinear optical devices and methods

In a process for making the superconductive composition YBa.sub.2 Cu.sub.3 O.sub.x, cupric carbonate or cupric oxalate is used as the copper source and barium carbonate as the barium source to achieve higher densification.

Method of making a high density YBa Cu.sub.3 O.sub.x superconductor

A multilayer protective device is made by including a varistor composition (35) between a first plurality of interdigitated electrodes (30, 32) and a capacitor composition (36) between a second plurality of electrodes of the same device. The two compositions are chosen to have optimum sintering temperatures within about 10 percent of each other. Simultaneous sintering solidifies and laminates the two compositions into a single monolithic device.

Monolithic capacitor-varistor

A novel low sintering temperature ceramic composition particularly suitable for multilayer ceramic capacitors is disclosed. The composition comprises a mixture represented by the formula

Ceramic compositions and devices

A predominantly perovskite phase Pb(Zn.sub.x Mg.sub.1-x Nb.sub.2).sub.1/3 O.sub.3 ceramic is prepared by first forming a columbite precursor having the formula Zn.sub.x Mg.sub.1-x Nb.sub.2 O.sub.6 and reacting this material with PbO at temperatures of from 800.degree. C. to at least 1000.degree. C. as x varies from 0.025 to 0.7.

Method of preparing a ceramic composition

An electrical contact comprises a base metal and an electroplated nickel layer thereover wherein said nickel layer is preferentially oriented in a &lt;111&gt; crystallographic plane along the surface of the nickel.

Electrical contacts

A ceramic capacitor with high Q factor and small temperature coefficients is made using a sintered dielectric comprising

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West Windsor Township, NJ, United States of America

Hung C Ling