Stephen J O'Brien

US Patent:

52553329, Oct 19, 1993

Filed:

Jul 16, 1992

Appl. No.:

7/915918

Inventors:

David F. Welch - Palo Alto CA
Donald R. Scifres - San Jose CA
Robert G. Waarts - Palo Alto CA
Amos A. Hardy - Stanford CA
David G. Mehuys - Sunnyvale CA
Stephen O'Brien - Sunnyvale CA

Assignee:

SDL, Inc. - San Jose CA

International Classification:

G02B 636

US Classification:

385 17

Abstract:

An optical crossbar switch matrix for use in switching optical signals from a first set of optical fibers to a second set of optical fibers, in any order, which is characterized by having a matrix of rows and columns of diffraction gratings formed in a semiconductor heterostructure. Each grating is independently biased with either a forward or reverse bias voltage to switch the grating between a reflective state and a transmissive state. The gratings are oriented at an angle relative to the rows and columns so that when the Bragg condition for the light received from an optical film is met, a portion of the light is diffracted from the row in which it is propagating into a column toward another optical fiber. The heterostructure may include optical amplifiers to restore the optical signal to its original power level. Beam expanding, collimating and focussing optics may also be integrated into the heterostructure.

US Patent:

53496027, Sep 20, 1994

Filed:

Mar 15, 1993

Appl. No.:

8/031684

Inventors:

David G. Mehuys - Menlo Park CA
Stephen O'Brien - Sunnyvale CA
David F. Welch - Menlo Park CA

Assignee:

SDL, Inc. - San Jose CA

International Classification:

H01S 308

US Classification:

372 98

Abstract:

A coherent light source, such as a laser oscillator and a monolithic MOPA device, and a broad area light amplifying device, all characterized by having a leaky waveguide beam expander coupled thereto for expanding a single mode beam into a wide light beam in a coherent manner. The beam expander comprises an elongated antiguide core of a first refractive index and a radiated-wave receiving region of a higher refractive index to receive lightwaves laterally radiated from the antiguide core. This beam expander can be located at an output end of a single mode laser oscillator to receive and expand the beam, at an input end of a broad area optical power amplifier to allow the amplifier to accept a narrow input beam, or between the laser oscillator and power amplifier in a MOPA device. The beam expander elements can also be located partially or entirely within the resonant optical cavity of a laser oscillator.