Robert K Lang

US Patent:

6404542, Jun 11, 2002

Filed:

Jul 10, 2000

Appl. No.:

09/613519

Inventors:

Mehrdad Ziari - Pleasanton CA
David F. Welch - Menlo Park CA
Vincent G. Dominic - Fremont CA
Bardia Pezeshki - San Jose CA
Robert J. Lang - Pleasanton CA

Assignee:

SDL, Inc. - San Jose CA

International Classification:

H01S 300

US Classification:

3593413, 35934133

Abstract:

A pump source for rare earth and Raman amplifiers or for distributed amplification uses two or more light sources to generate two source beams that are combined by a beam combiner to form the output pump beam. In accordance with one embodiment, the light sources are a diode laser array having be two or more monolithic laser stripes providing dual output beams having substantially the same polarization, such as the TE mode. One of the polarized due outputs is rotated 90Â and both beams are applied to a birefringent crystal that combines the beams for insertion into an optical fiber or into a rare earth doped fiber or into a fiber capable of Raman amplification via SRS. The power output of each polarization in the combined beam can be measured and used to drive a feedback circuit that controls the current provided to each diode in order to maintain the power in the two polarization components of the output beam equal.

US Patent:

6433920, Aug 13, 2002

Filed:

Sep 18, 2000

Appl. No.:

09/664986

Inventors:

David F. Welch - Menlo Park CA
Robert J. Lang - Pleasanton CA
Edward C. Vail - Menlo Park CA
Mehrdad Ziari - Pleasanton CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 300

US Classification:

359334, 3593371

Abstract:

An optical amplifier with a flattened wideband response is obtained by coupling counter-propagating pumping energy into an optical waveguide to cause Raman amplification in the optical waveguide, and by reflecting an amplified signal received from the optical waveguide into an output waveguide using a reflector having a spectral characteristic that is complementary to the spectral gain characteristic of the Raman amplification.

US Patent:

6477295, Nov 5, 2002

Filed:

Jan 20, 2000

Appl. No.:

09/488166

Inventors:

Robert J. Lang - Pleasanton CA
Robert G. Waarts - Fremont CA
Ian J. Booth - Sooke, CA
David M. Giltner - Fremont CA
Steven Sanders - Palo Alto CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G02B 626

US Classification:

385 31, 385 27, 385127, 372 6

Abstract:

Apparatus for coupling light into a fiber, such as a double clad fiber (DCF) having a core having a refractive index n , surrounded by an inner cladding having refractive index n which is surrounded by an outer cladding having a refractive index n , where n n n. An optical coupler medium, referred to as a Fiber Space Division Multiplexor or FSDM, is formed on an exposed portion of the fiber inner cladding at a position along the length of the fiber without interfering with the continuity of its core and provides at, at least one position, the imaging of light external of the fiber into the inner cladding interface and its waveguiding with the inner cladding of the fiber. The FSDM coupler comprises an optical material in optical contact or integrated with the inner cladding and having a refractive index substantially equal to n. The coupler medium may also be employed with a fiber having no core and where the inner cladding would function as a multimode core. Also, disclosed are formed reflectors for reflecting back residual, unabsorbed pump light backward into the DCF inner cladding for absorption within the core doped with a rare earth active material.

US Patent:

6525872, Feb 25, 2003

Filed:

Aug 17, 1999

Appl. No.:

09/375687

Inventors:

Mehrdad Ziari - Pleasanton CA
Stephen OBrien - Orefield PA
Mats Hagberg - Västra Frölunda, SE
Robert J. Lang - Pleasanton CA
Edward Vail - Menlo Park CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 300

US Classification:

3593413, 3593411

Abstract:

High power semiconductor lasers for pumping fiber devices, such as fiber amplifiers and fiber lasers, include an optical gain region disposed between a rear end and the output end, the width of the optical gain region being greater at the output end than at the rear end. The optical gain region may include a single mode channel region coupled to a flared amplifier region. The light output from the laser is coupled via a lens system into a fiber for propagating to the fiber device to be pumped. Light is fedback into the laser, for example from a fiber Bragg grating, to induce the laser to operate in coherence collapse. The broad bandwidth output associated with coherence collapse permits the laser to deliver high optical powers into the fiber without the onset of stimulated Billion scattering. Fiber grating feedback improves the quality of the beam output by the laser, thus enhancing coupling efficiency into the fiber. The pump laser may be used to pump multiple fiber devices.

US Patent:

6542529, Apr 1, 2003

Filed:

Feb 1, 2000

Appl. No.:

09/495208

Inventors:

Mats Hagberg - Västra Frölunda, SE
Robert J. Lang - San Jose CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 500

US Classification:

372 46, 372 93

Abstract:

A broad stripe semiconductor laser has a folded cavity that permits the laser to produce output powers into a high quality beam with low divergence. The folded cavity includes a first material region disposed within the cavity having a first refractive index and a second material region having a second refractive index less than the first refractive index, and forming a first interface with the first material region. The first interface is disposed to reflect a lowest order reflection mode light beam propagating within the first material region. The first interface is disposed at a predetermined angle so that the lowest order reflection mode intracavity light beam is incident on the first interface at an angle below the critical total internal reflection angle, and higher order reflection modes are incident on the first interface at angles in excess of the total internal reflection critical angle. The interface may be curved to control the divergence to the light emitted from the cavity.

US Patent:

6603595, Aug 5, 2003

Filed:

Jun 26, 2002

Appl. No.:

10/185458

Inventors:

David F. Welch - Menlo Park CA
Robert J. Lang - Pleasanton CA
Edward C. Vail - Menlo Park CA
Mehrdad Ziari - Pleasanton CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 300

US Classification:

359334, 3593371

Abstract:

An optical amplifier with a flattened wideband response is obtained by coupling counter-propagating pumping energy into an optical waveguide to cause Raman amplification in the optical waveguide, and by reflecting an amplified signal received from the optical waveguide into an output waveguide using a reflector having a spectral characteristic that is complementary to the spectral gain characteristic of the Raman amplification.

US Patent:

6748137, Jun 8, 2004

Filed:

Jul 24, 2001

Appl. No.:

09/915186

Inventors:

Edmund L. Wolak - Palo Alto CA
Lei Xu - Richmond CA
Robert Lang - Pleasanton CA
Tae J. Kim - San Jose CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G02B 625

US Classification:

385 33, 385 38

Abstract:

A microlens on the end of an optical fiber has reduced back reflections to a light source, such as a pump laser diode. In a particular embodiment, the microlens is lapped on two radii, at least one of which is offset from the center axis of the fiber, to form a point on the end of the fiber, thus reducing a surface for reflecting light back to the light source. In another embodiment, the microlens is formed with two different side surface angles to accommodate misalignment of the light source to the fiber mount. In another embodiment a Fresnel lens structure on the end of the fiber operates optically as an angled chisel lens.

US Patent:

6754243, Jun 22, 2004

Filed:

Aug 9, 2001

Appl. No.:

09/925963

Inventors:

Mark Missey - Santa Clara CA
Bardia Pezeshki - Redwood City CA
Robert J. Lang - Pleasanton CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

H01S 310

US Classification:

372 20, 372 23, 372 50, 372 96

Abstract:

A wavelength tunable laser includes a distributed feedback (DFB) array with first and second DFB laser diodes that generate first and second beams of light in first and second wavelength ranges. A microelectromechanical (MEMS) optical element selectively couples one of the first and second beams of light from the DFB laser array into an optical waveguide. The MEMS optical element includes a collimating lens and a thermal or electrostatic MEMS actuator for moving the collimating lens to select the one of the first and second beams of light. A focusing lens is located between the collimating lens and the optical waveguide. Alternately, the MEMS optical element includes a fixed collimating lens that collimates the first and second beams of light, a mirror, and a MEMS actuator for tilting the mirror to select the one of the first and second beams of light.