Sung Sook Yoo

US Patent:

57969027, Aug 18, 1998

Filed:

Jul 5, 1996

Appl. No.:

8/682863

Inventors:

Rajaram Bhat - Middletown NJ
Catherine Caneau - Red Bank NJ
Mark A. Koza - Colonia NJ
Sung Joo Yoo - Long Branch NJ

Assignee:

Bell Communications Research, Inc. - Morristown NJ

International Classification:

G02B 600

US Classification:

385122

Abstract:

A waveguide having alternating regions of different crystallographic orientations, thereby providing quasi-phase-matching for a non-linear frequency conversion, in which two wafers with or without epitaxial layers thereon are bonded together having different, preferably opposed, crystallographic orientations. One wafer is etched away, and a grating is etched such that one part of the grating has the orientation of one wafer and the other part has the orientation of the other wafer. Thereafter, a waveguide structure is epitaxially deposited upon the differentially oriented template so that the waveguide is differentially oriented in its axial direction. Thereby, quasi-phase-matching non-linear effects can be achieved. Several important devices can thereby be achieved, including a coherent optical source using frequency doubling and a frequency converter useful in wavelength division multiplexed communication, as well as others.

US Patent:

6186918, Feb 13, 2001

Filed:

Jul 16, 1999

Appl. No.:

9/354609

Inventors:

Sung Ryul Yoo - Norwalk CA

International Classification:

F16H 710
B62M 100

US Classification:

474112

Abstract:

An adjustable axle assembly for use with a wheel comprises a first hub defining a first aperture in an off-centered position so geometric centers of the first aperture and the first hub are eccentrically located, the first aperture adapted to receive an axle; a second hub defining a second aperture in an off-centered position so the geometric centers of the second aperture and the second hub are eccentrically located, the second aperture adapted to rotationally receive the first hub; and a locking assembly coupling and controlling the rotational movement of the first hub and the second hub. The second aperture of the second hub includes a plurality of indents formed on the inner surface of the second hub separated by a predetermined angle for releasably engaging the locking assembly, wherein the plurality of indents represents an angle of eccentric rotation of the wheel. At least one of the plurality of indents positions the first hub with respect to the second hub to place the axle in a geometric center of the second hub to provide a concentric rotation of the wheel.