Polaroid Corporation

Gte Laboratories Incorporated

Norman A Sanford

William C Robinson

Amaresh Mahapatra

James M Connors

Donald H McMahon

William J Miniscalco

Alexander Lempicki

William A Dyes

Optimal sum-frequency and second harmonic generators are fabricated in ferroelectric waveguides by taking into account the interference between generated beams of Cerenkov radiation.

Proton-exchanged waveguides for sum-frequency generation

An external light modulator which relies on efficient changes in electro-optic coupling of light between copolarized guided modes in a single waveguide channel formed in a lithium niobate or lithium tantalate substrate by proton exchange with benzoic acid.

Optical modulation device

An optical modulator comprises a crystal whose top surface includes a channel waveguide whose axis makes an angle with the crystal optic axis larger than the critical angle for TE-polarized leaky mode propagation. An electrode structure overlies the top surface of the crystal for inducing mode conversion of TM-polarized waves propagating in the waveguide to lossy radiation modes.

Channel waveguide modulator

A TE-TM mode converter utilizes a Y-cut lithium niobate crystal which includes a straight titanium-diffused channel extending along the Z-axis of the crystal. A parallel pair of electrodes lie symmetrically on opposite sides of the channel. a.c. and d.c. voltage supplies are connected to the electrodes to supply voltages so as to effect complete conversion from one direction of polarization to the other direction of polarization of a wave applied as an input to one end of the channel for abstraction at the opposite end.

TE-TM mode converter

A planar waveguide device including metallic electrodes has a buffer layer of reduced ordinary index of refraction formed in a substrate between its waveguide and electrodes. The device is preferably formed by first fabricating the waveguide in an x-or y-cut substrate of crystalline material, subsequently overcoating the substrate, including the waveguide, with a layer of magnesium, oxidizing the magnesium at temperature to form the buffer layer and then laying the electrodes over the buffer layer. Alternatively, the buffer layer may be formed by a proton exchange process.

Planar waveguide mode converter device

Integrated optic resonant structures for use in optical communications and sensing applications requiring control or detection of electromagnetic radiation in the optical region of the spectrum. Preferably of planar form, the structures comprise a substrate made of a ferroelectric crystalline material in which there is formed by selectively exchanging protons for an ionic constituent of the substrate at least one optically continuous waveguiding region having predetermined resonant characteristics. At least one other waveguiding region is similarly formed in the substrate to optically couple with the resonant region and includes at least one port by which radiation can be coupled in and out of the substrate. The substrate material is preferably lithium niobate (LiNbO.sub.3) or lithium tantalate (LiTaO.sub.3) in which lithium ions are selectively exchanged for protons supplied by diffusion from a hydrogen rich acid. Applications for the structures include use as a band pass or reject filter, bus tap, sensor, or modulator.

Integrated optic resonant structres and fabrication method

Apparatus employing a light beam to affect another light beam. A primary beam of linearly polarized monochromatic light is directed on an element of chromium chalcogenide spinel magnetic semiconductor, specifically single crystal CdCr.sub.2 Se.sub.4. A control beam of monochromatic light is selectively elliptically polarized and directed at the element. As the light beams traverse the same path through the element the circularly polarized control beam interacts with the element thereby changing the effect of the element on the linearly polarized primary beam to rotate the plane of linear polarization of the primary beam. A linear polarization analyzer receives the primary beam from the element and passes, blocks, or diverts light depending upon the plane of linear polarization of the incident light.

Apparatus for controlling the rotation of the plane of linear

A method for externally modulating an optical carrier wave by propagating the wave through a single channel waveguide structured to have an output whose optical power in the near field is distributed in a predetermined spatial pattern, selectively changing the optical power distribution pattern in correspondence with an information signal, and spatially filtering the power distribution pattern so that only the power available within selected region of the pattern is transmitted beyond the point of spatial filtering where it is available as an optical carrier wave whose intensity is modulated in correspondence with the information signal.

Growing community of inventors

Stillriver, MA, United States of America

Norman A Sanford