Lucent Technologies Inc.

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

At+t Corp.

Benjamin Irvin Greene

Herman M Presby

Thomas Andrew Strasser

Chellappan Narayanan

Cynthia A Volkert

Corrado Pietro Dragone

Alastair M Glass

Robert M Atkins

Ahmet Refik Kortan

Nonna Kopylov

Kuochou Tai

Leah R Williams

Joseph Orenstein

Rebecca R Millard

Mrinal Thakur

The specification describes ceram-glass compositions useful for electro-optic devices. The compositions have active ferroelectric ingredients in a tellurium oxide host. Proper processing of the ceram-glass produces highly transparent material with desirable ferroelectric properties. The ceram-glass materials can be used for electro-optic devices in both bulk and thin film applications.

SrO &plus; BaO &plus; Nb2O5 &plus; TeO2 ceram-glass electro-optical device and method of making

In accordance with the invention glass waveguide devices are provided with enhanced temperature stability by incorporating within appropriate lengths of the waveguides a transparent compensating material having a refractive index variation with temperature that differs substantially from that of the waveguide. The compensating material can be a non-glass material, such as a liquid, driven into the glass by heat and pressure. In a preferred embodiment, D.sub.2 O is incorporated into waveguides for optical communications. The D.sub.2 O is transparent to the preferred communications wavelengths centered at about 1.55 .mu.m and has a dn/dT opposite in polarity to the dn/dT of glass. The resulting structure exhibits enhanced temperature stability with reduced magnitude of dn/dT. The technique is particularly useful in devices based on interference between multiple waveguides, as it is not necessary to reduce dn/dT to zero in the respective waveguides. It suffices to compensate the differences. Such compensation can be achieved by compensating materials having dn/dT of either the same polarity as the dn/dT of the waveguides or the opposite polarity. Preferred embodiments include routers, Fourier filters and Bragg filters. In single waveguide devices such as gratings, compensating materials of opposite polarity can substantially enhance the temperature stability.

Method for altering the temperature dependence of optical waveguides

A method is provided of trimming the optical coupling ratio of an optical coupler to a prescribed value. The optical coupler is formed from a plurality of waveguides which each include a core and cladding. In accordance with the method, an irradiation energy is selected that is absorbed by portions of the waveguides located in a coupling region. A dosage of radiation is applied to the waveguide portions at least sufficient to adjust the optical coupling ratio to the prescribed value. The radiation, which may be absorbed by the cladding and/or the core of the waveguides, causes a change in the refractive index difference between the core and cladding of the waveguides. This change in the refractive index difference will result in a change in the optical coupling ratio of the device.

Radiolytic method for trimming planar waveguide couplers

A method for reducing the inherent polarization shift caused by birefringence between the TE and TM modes of an optical signal propagating in an optical grating which has a plurality of waveguides includes the step of: irradiating the waveguides of the optical grating for different periods of time to induce a compensating polarization shift that substantially reduces the inherent polarization shift. If desired, a compensating polarization shift may be induced which not only reduces but also substantially eliminates the inherent polarization shift.

Method for reducing birefringence in optical gratings

A method of making a silicate optical waveguide structure for transforming an optical beam of a first modal spot size to a beam of a second modal spot size includes the step of selecting an irradiation energy which is at least partially absorbed by the cladding of the structure. A variable dosage of radiation is then provided along the length of the structure. The radiation has an energy equal to the selected irradiation energy so that a refractive index change of the cladding is greater than a refractive index change of the core.

Radiolytic method for making a mode-field transforming optical waveguide

A method for reducing birefringence in a silicate waveguide structure having a waveguide core and cladding includes the step of selecting an irradiation energy that induces compaction in the cladding. The waveguide structure is then irradiated with radiation having an energy equal to the irradiation energy to induce a reduction in birefringence.

Radiolytic modification of birefringence in silica planar waveguide

An optical system is disclosed which includes at least a first source of electromagnetic radiation (signal beam radiation), a device for processing the signal beam radiation, and a detector for detecting the processed signal beam radiation. The processing device functions, for example, as an amplitude modulator, a demultiplexer, or a switch, and includes a material region exhibiting a nonlinear optical response at one or more resonant wavelengths of electromagnetic radiation, as well as at least a second source of electromagnetic radiation (control beam radiation) for selectively inducing the nonlinear optical response. Significantly, the wavelength, duration and intensity of the control beam radiation are chosen to induce a resonant, nonlinear optical response, essentially free of any relatively slow component, in said material region at repetition rates higher than about 1.25.times.10.sup.4 Hz, or higher than about 3.3.times.10.sup.10 Hz, or even as high, or higher, than about 2.5.times.10.sup.11 Hz.

Growing community of inventors

Westfield, NJ, United States of America

Benjamin Irvin Greene