Mark A Pratt

US Patent:

6483621, Nov 19, 2002

Filed:

Jul 28, 2000

Appl. No.:

09/627819

Inventors:

Jeffrey C. Adams - Seattle WA
Mark Pratt - Seattle WA
Micah J. Barclay - Redmond WA

Assignee:

Terabeam Corporation - Kirkland WA

International Classification:

H04B 1000

US Classification:

359159, 359181, 359189, 359193

Abstract:

A transmitted light signal, such as laser light, is modulated by a data signal and by a tracking signal. The tracking signal has a modulation depth that is substantially smaller than a peak-to-peak amplitude of the light signal. At reception, the tracking signal is recovered from the modulated light signal and is used to determine an orientation of a receiver with respect to the transmitted light signal.

US Patent:

6490070, Dec 3, 2002

Filed:

Jul 28, 2000

Appl. No.:

09/627279

Inventors:

Jeffrey C. Adams - Seattle WA
Mark Pratt - Seattle WA
Micah J. Barclay - Redmond WA

Assignee:

Terabeam Corporation - Kirkland WA

International Classification:

H04B 1000

US Classification:

359156, 359154, 359155, 359159, 359172, 359181

Abstract:

A polarization of a light signal is modulated to provide polarization tracking in a wireless optical communication system. The light signal having the modulated polarization, such as a sinusoidally varying polarization, is transmitted from an optical transmitter having polarization-maintaining fiber. The light signal having the modulated polarization is received at an optical receiver. A portion of the light signal is directed to an analyzer that detects the modulated polarization and generates an amplitude-modulated light signal corresponding to the modulated polarization. The amplitude-modulated light signal is directed to a tracking detector, such as a quad cell detector, that generates an amplitude-modulated electronic signal corresponding to the amplitude-modulated light signal. The amplitude-modulated electronic signal can be subsequently used to control or perform tracking of the optical receiver. Such tracking can include adjustment of an orientation of the optical receiver with respect to the light signal received from the transmitter.

US Patent:

6608708, Aug 19, 2003

Filed:

Jul 28, 2000

Appl. No.:

09/627815

Inventors:

Charles Gregory Amadon - Seattle WA
Richard D. Rallison - Paradise UT
John J. Schuster - Bellevue WA
Harold A. Brown - Renton WA
Mark Pratt - Seattle WA

Assignee:

Terabeam Corporation - Kirkland WA

International Classification:

G03H 100

US Classification:

359 15, 359 19, 359152

Abstract:

A holographic optical element (HOE) device is mounted in a receiver unit, such as a wireless optical telecommunication system receiver. The HOE device includes a developed emulsion material having an interference pattern recorded thereon, sandwiched between a pair of elements, such as a pair of clear glass plates. In operation, the HOE device uses the recorded interference pattern to diffract incident light rays towards an optical processing unit of the system receiver. The optical processing unit includes a photodetector that detects the diffracted light rays. The system receiver can include various other components and/or can have various configurations. In one configuration, a plurality of mirrors is used to control the direction of the light rays coming from the HOE device, and a collimating optical assembly collimates these light rays. A beam splitting optical assembly can be used to split the light rays into a tracking channel and a communication channel.

US Patent:

6657775, Dec 2, 2003

Filed:

Aug 31, 2001

Appl. No.:

09/945324

Inventors:

Jason N. Farmer - Seattle WA
Mark R. Pratt - Seattle WA
Richard D. Romea - Seattle WA

Assignee:

Nlight Photonics Corporation - Seattle WA

International Classification:

H01S 300

US Classification:

359334, 3593413, 372 20

Abstract:

The present invention is in general related to efficient operation of an external cavity laser and more particularly to a system and method of operating an external cavity laser utilizing one or more controlled linewidth gain elements. Specifically, the linewidth of an gain elements is broadened so that Brillouin scattering mechanisms in a gain medium are eliminated or reduced.

US Patent:

6663785, Dec 16, 2003

Filed:

Mar 6, 2002

Appl. No.:

10/092018

Inventors:

Zhe Huang - Fremont CA
Mark A. Devito - Vancouver WA
Mike P. Grimshaw - Vancouver WA
Paul A. Crump - Portland OR
Jason N. Farmer - Seattle WA
Mark R. Pratt - Seattle WA

Assignee:

nLight Photonics Corporation - Seattle WA

International Classification:

B44C 122

US Classification:

216 2, 216 24, 372 23, 372 46, 372 50, 372 69, 438689

Abstract:

Embodiments of the present invention are directed to method of fabrication of a broadband emitter array. Embodiments of the present invention may grown a first set of emitters possessing a first quantum well characteristic (e. g. , quantum well thickness or composition). A portion of the first set of emitters is removed by etching. In place of the removed emitters, a second set of emitters is regrown with said second set of emitters possessing a different quantum well characteristic. By fabricating the emitters sets in this manner, a unitary emitter array may be fabricated that possesses an increased bandwidth, e. g. , the first and second sets of emitters may be associated with different center wavelengths. Embodiments of the present invention may utilize emitter arrays fabricated in this manner in, for example, incoherently beam combined (IBC) lasers and in Raman amplifier systems.

US Patent:

6665471, Dec 16, 2003

Filed:

Aug 13, 2001

Appl. No.:

09/929837

Inventors:

Jason N. Farmer - Seattle WA
Scott R. Karlsen - Lynnwood WA
Mark R. Pratt - Seattle WA

Assignee:

Nlight Photonics Corporation - Seattle WA

International Classification:

G02B 634

US Classification:

385 37, 385 24, 372 23, 372 97, 372 99, 372102, 398 87

Abstract:

The present invention is directed to a system and method which utilize an incoherently beam combined (IBC) laser. The IBC laser includes a plurality of emitters with each of the emitters possessing a partially reflective surface on their front facet. The partially reflective surface causes resonant wavelengths to be defined. In certain embodiments, the system and method arrange the external cavity and emitter spacings of the IBC laser such that the center feedback wavelength provided to each emitter is an etalon resonant wavelength. In other embodiments, the range of feedback wavelengths is adapted so that it is greater than the free spectral range (the separation in wavelength space between adjacent etalon resonant wavelengths).

US Patent:

6678079, Jan 13, 2004

Filed:

Mar 9, 2001

Appl. No.:

09/802672

Inventors:

Charles Gregory Amadon - Seattle WA
Richard D. Rallison - Paradise UT
Mark Pratt - Seattle WA
David P. Bajorins - Redmond WA
Lawrence Cooper Stapleton - Seattle WA
Richard B. Riday - Kirkland WA
Harold Alexander Brown - Renton WA
William Joseph Lauby - Mukilteo WA
Michael Thomas - Belmont MA
Scott William Sparrold - Bothell WA

Assignee:

Terabeam Corporation - Kirkland WA

International Classification:

G02B 532

US Classification:

359 15, 19 34, 398135, 398139

Abstract:

A holographic optical element (HOE) device is mounted in wireless optical telecommunication system transceiver. The HOE device includes a developed emulsion material having an interference pattern recorded thereon, sandwiched between a pair of elements, such as a pair of clear glass plates. In operation, the HOE device uses the recorded interference pattern to diffract received light rays towards an optical processing unit of the system receiver. A transmitter unit can be positioned at least in part behind the HOE device. An opening in the emulsion material allows a light signal transmitted from the transmitter unit to be substantially unaffected by the recorded interference pattern. The transceiver can also include a spotting scope and an alignment beacon.

US Patent:

6768876, Jul 27, 2004

Filed:

Jul 28, 2000

Appl. No.:

09/627817

Inventors:

Ronald D. Steiger - Redmond WA
Mark R. Pratt - Seattle WA

Assignee:

Terabeam Corporation - Kirkland WA

International Classification:

H04B 1000

US Classification:

398156, 398202, 398208, 398209, 398213, 398137, 398122, 398129, 398131, 375316, 375317, 375318

Abstract:

A tracking system and method in an optical communications system utilizing an optical communications beam. In one embodiment, the disclosed optical communications system includes a communications receiver circuit and a tracking circuit. The optical communications system generates a communications signal. The tracking system includes a tracking detector having a plurality of regions coupled to a corresponding plurality of tracking channel circuits. Each of the tracking channel circuits includes an optical detector coupled to receive the optical communications beam. The peak-to-peak amplitude modulation in the optical communications beam is measured by substantially reducing or removing a direct current (DC) offset present in the optical communications beam. In one embodiment, after the DC offset is substantially reduced or removed, the signal is then amplified, mixed with the communications signal and then filtered. The filtered signal is one of a plurality of tracking signal outputs, which are input to an alignment circuit.