Michael J. Freeman Inventions, Patents and Patent Applications - Justia Patents Search

Patent number: 7535007

Abstract: A gas sensor usable in harsh environments includes a multiple chamber radiant energy transmission path which extends between a multi-channel emitter and a multi-channel detector. Chamber length and gas selection are establishable using a movable element with an aperture. The element is located between the emitter and the detector on the transmission path. Radiant energy from the emitter is reflected between the emitter and the element, prior to passing through the element to impinge on the detector.

Type: Grant

Filed: February 26, 2008

Date of Patent: May 19, 2009

Assignee: Honeywell International Inc.

Inventors: Michael J. Freeman, Steven Gautieri

Patent number: 7448063

Abstract: The present invention relates to an interactive digital system enabling viewers full and active participation in experiencing a live broadcast event. Particularly, the presentation of the live event is personalized for the viewer through the provision of various options, including multiple video streams, associated with different c125 amera angles, for example, and integrated audio and graphics segments. Further, information obtained from related Web sites can be integrated into the live program. Various video and audio streams are collected from a live event and forwarded to a central control studio. Graphics are created at the central studio on a personal computer or chyron device. After receiving the video, audio and graphics signals, the signals are digitized and compressed in digital compressors. These signals are then combined with special data codes into a "digital package," and subsequently, transmitted over a cable distribution system.

Type: Grant

Filed: April 19, 2002

Date of Patent: November 4, 2008

Assignee: ACTV, Inc.

Inventors: Michael J. Freeman, Craig Ullman

Patent number: 7233432

Abstract: In one of several embodiments, a method of communicating optical signals comprises communicating a plurality of optical signals over an optical communications medium, wherein each of at least some of the plurality of optical signals comprises a launch power that is a function of a noise property measured at or near a center wavelength of that signal. Launch powers of the plurality of optical signals primarily decrease with increasing center wavelengths of the plurality of optical signals.

Type: Grant

Filed: August 30, 2002

Date of Patent: June 19, 2007

Assignee: Xtera Communications, Inc.

Inventors: Mohammed N. Islam, Michael J. Freeman, Amos Kuditcher

Patent number: 7079176

Abstract: The present invention relates to an interactive digital system enabling viewers full and active participation in experiencing a live broadcast event. Particularly, the presentation of the live event is personalized for the viewer through the provision of various options, including multiple video streams, associated with different camera angles, for example, and integrated audio and graphics segments. Further, information obtained from related Web sites can be integrated into the live program. Various video and audio streams are collected from a live event and forwarded to a central control studio. Graphics are created at the central studio on a personal computer or chyron device. After receiving the video, audio and graphics signals, the signals are digitized and compressed in digital compressors. These signals are then combined with special data codes into a "digital package," and subsequently, transmitted over a cable distribution system.

Type: Grant

Filed: October 27, 2000

Date of Patent: July 18, 2006

Assignee: ACTV, Inc.

Inventors: Michael J. Freeman, Craig Ullman

Patent number: 6943936

Abstract: A Raman amplifier includes a Raman gain fiber comprising a length of high-dispersion gain fiber and operable to receive at least one optical signal. The Raman amplifier also includes at least one pump source capable of generating at least one pump signal that co-propagates within the Raman gain fiber with at least a portion of the at least one optical signal received by the Raman gain fiber. The length of the high-dispersion gain fiber is at least ten (10) times a walk off length between the at least one pump signal and at least one wavelength of the at least one optical signal received by the Raman gain fiber. In addition, the length of high-dispersion gain fiber is at least two (2) times a walk off length between at least two optical signal wavelengths of the at least one optical signal received by the Raman gain fiber.

Type: Grant

Filed: August 2, 2002

Date of Patent: September 13, 2005

Assignees: The Regents of the University of Michigan, Xtera Communications, Inc.

Inventors: Mohammed N. Islam, Michael J. Freeman

Patent number: 6924926

Abstract: A laser diode pump includes a plurality of laser diodes each capable of generating a lasing wavelength. The laser diode pump further includes at least one wavelength combiner operable to combine the plurality of lasing wavelengths generated by the plurality of laser diodes into a multiple wavelength pump signal. In one particular embodiment, at least two of the plurality of lasing wavelengths generated by the plurality of laser diodes comprise a wavelength between 1270 nm and 1350 nm.

Type: Grant

Filed: August 2, 2002

Date of Patent: August 2, 2005

Assignees: Xtera Communications, Inc., The Regents of the University of Michigan

Inventors: Mohammed N. Islam, Michael J. Freeman

Publication number: 20040261127

Abstract: The present invention relates to an interactive digital system enabling viewers full and active participation in experiencing a live broadcast event. Particularly, the presentation of the live event is personalized for the viewer through the provision of various options, including multiple video streams, associated with different camera angles, for example, and integrated audio and graphics segments. Further, information obtained from related Web sites can be integrated into the live program. Various video and audio streams are collected from a live event and forwarded to a central control studio. Graphics are created at the central studio on a personal computer or chyron device. After receiving the video, audio and graphics signals, the signals are digitized and compressed in digital compressors. These signals are then combined with special data codes into a “digital package,” and subsequently, transmitted over a cable distribution system.

Type: Application

Filed: January 28, 2004

Publication date: December 23, 2004

Applicant: ACTV, Inc.

Inventors: Michael J. Freeman, Craig Ullman

Patent number: 6819479

Abstract: In one embodiment, an optical amplifier includes a gain medium operable to receive a plurality of signals each having a center wavelength and a noise figure associated with at least a portion of the amplifier and varying as a function of wavelength. At least two of the plurality of signals have launch powers that are a function of a magnitude of the noise figure measured at or near the center wavelength of that signal.

Type: Grant

Filed: December 20, 2001

Date of Patent: November 16, 2004

Assignee: Xtera Communications, Inc.

Inventors: Mohammed N. Islam, Michael J. Freeman, Pavle Gavrilovic, Andrzej Kaminski

Patent number: 6808835

Abstract: A system for the humidification of polymer electrolyte membrane fuel cells, the system comprising a first layer and a second layer; wherein the first layer comprises a porous material (11) substantially coincident with a first surface of a polymer electrolyte membrane fuel cell (10); wherein the second layer comprises a non-absorbent material (12) substantially coincident with the first layer; and wherein perforations in the second layer allow air to flow through the first and second layers to a cathode (17) of the polymer electrolyte fuel cell.

Type: Grant

Filed: May 12, 2003

Date of Patent: October 26, 2004

Assignee: Qinetiq Limited

Inventors: Kevin J Green, Michael J Freeman, William R Slee

Publication number: 20040047020

Abstract: In one of several embodiments, a method of communicating optical signals comprises communicating a plurality of optical signals over an optical communications medium, wherein each of at least some of the plurality of optical signals comprises a launch power that is a function of a noise property measured at or near a center wavelength of that signal. Launch powers of the plurality of optical signals primarily decrease with increasing center wavelengths of the plurality of optical signals.

Type: Application

Filed: August 30, 2002

Publication date: March 11, 2004

Inventors: Mohammed N. Islam, Michael J. Freeman, Amos Kuditcher

Publication number: 20040042061

Abstract: An optical amplifier includes at least one Raman amplification stage. The Raman amplification stage includes one or more pump sources operable to generate a plurality of pump signals capable of being delivered to a gain medium carrying an optical signal. In one particular embodiment, at least one of the plurality of pump signals comprises a time modulated pump signal and wherein an amplified spontaneous emission penalty associated with the at least one time modulated pump signal comprises no more than fifteen (15) decibels.

Type: Application

Filed: August 30, 2002

Publication date: March 4, 2004

Inventors: Mohammed N. Islam, Michael J. Freeman, Amos Kuditcher

Publication number: 20040028974

Abstract: A system for the humidification of polymer electrolyte membrane fuel cells, the system comprising a first layer and a second layer; wherein the first layer comprises a porous material (11) substantially coincident with a first surface of a polymer electrolyte membrane fuel cell (10); wherein the second layer comprises a non-absorbent material (12) substantially coincident with the first layer; and wherein perforations in the second layer allow air to flow through the first and second layers to a cathode (17) of the polymer electrolyte fuel cell.

Type: Application

Filed: May 12, 2003

Publication date: February 12, 2004

Inventors: Kevin J Green, Michael J Freeman, William R Slee

Patent number: 6587259

Abstract: One aspect of the invention includes an optical amplifier operable to amplify a plurality of optical wavelength signals at least in part through Raman amplification. The amplifier includes an input operable to receive a plurality of wavelength signals and an output operable to communicate an amplified version of at least some of the plurality of wavelength signals. The amplifier further includes a pump assembly operable to generate one or more pump signals and a gain medium operable to receive the plurality of wavelength signals and the one or more pump signals and to facilitate amplification of at least some of the plurality of wavelength signals. The amplifier has associated with it a noise figure having a shape varying as a function of wavelength. At least one of the one or more pump signals is operable to have its power varied to selectively control the shape of the noise figure.

Type: Grant

Filed: July 27, 2001

Date of Patent: July 1, 2003

Assignee: Xtera Communications, Inc.

Inventors: Mohammed N. Islam, Carl A. DeWilde, Michael J. Freeman

Publication number: 20030095324

Abstract: A multi-stage Raman amplifier includes a first Raman amplifier stage having a first sloped gain profile operable to amplify a plurality of signal wavelengths, and a second Raman amplifier stage having a second sloped gain profile operable to amplify at least most of the plurality of signal wavelengths after those wavelengths have been amplified by the first stage. The second sloped gain profile is approximately complementary slope to the slope of the first sloped gain profile. The combined effect of the first and second Raman stages contributes to an approximately flat overall gain profile over the plurality of signal wavelengths.

Type: Application

Filed: November 12, 2002

Publication date: May 22, 2003

Applicant: Xtera Communications, Inc., a Delaware corporation

Inventors: Mohammed N. Islam, Carl A. Dewilde, Michael J. Freeman

Patent number: 6567430

Abstract: In one embodiment, a Raman oscillator includes at least one laser cavity and a distributed gain fiber positioned in the at least one laser cavity having a single spatial mode over a pumping wavelength to a signal wavelength. The oscillator also includes a coupler adapted to be coupled to a pumping mechanism to pump the distributed gain fiber at the pumping wavelength to obtain an optical signal wherein distributed gain is provided by Raman amplification over at least one cascade order corresponding to the pumping wavelength. A filter is positioned in the at least one laser cavity and has at least one pass band with a transmission peak placed approximately at the at least one cascade order to filter the optical signal to obtain a filtered optical signal having the signal wavelength. The filter has a substantially continuous sinusoidal filter function over at least one period of the filter function.

Type: Grant

Filed: September 21, 1999

Date of Patent: May 20, 2003

Assignees: Xtera Communications, Inc., The Regents of the University of Michigan

Inventors: Mohammed N. Islam, Michael J. Freeman, Hayden H. Harris

Publication number: 20030067674

Abstract: A multi-stage Raman amplifier includes a first Raman amplifier stage having a first sloped gain profile operable to amplify a plurality of signal wavelengths, and a second Raman amplifier stage having a second sloped gain profile operable to amplify at least most of the plurality of signal wavelengths after those wavelengths have been amplified by the first stage. The second sloped gain profile is approximately complementary slope to the slope of the first sloped gain profile. The combined effect of the first and second Raman stages contributes to an approximately flat overall gain profile over the plurality of signal wavelengths.

Type: Application

Filed: November 5, 2002

Publication date: April 10, 2003

Applicant: Xtera Communications, Inc., a Delaware corporation

Inventors: Mohammed N. Islam, Carl A. Dewilde, Michael J. Freeman

Publication number: 20030067671

Abstract: In one aspect of the invention, a method of amplifying optical signals includes identifying one of a plurality of pump signals driving an amplification system as a failing pump signal comprising a reduced power compared to a normal power of the failing pump signal. The method further includes adjusting the power of at least one other of the plurality of pump signals based at least in part on the failing pump signal to at least partially compensate for a degradation of performance of the amplification system that would otherwise be caused by the reduction in power of the failing pump signal.

Type: Application

Filed: October 5, 2001

Publication date: April 10, 2003

Inventors: Mohammed N. Islam, Carl A. deWilde, Michael J. Freeman

Publication number: 20030053507

Abstract: A laser diode pump includes a plurality of laser diodes each capable of generating a lasing wavelength. The laser diode pump further includes at least one wavelength combiner operable to combine the plurality of lasing wavelengths generated by the plurality of laser diodes into a multiple wavelength pump signal. In one particular embodiment, at least two of the plurality of lasing wavelengths generated by the plurality of laser diodes comprise a wavelength between 1270 nm and 1350 nm.

Type: Application

Filed: August 2, 2002

Publication date: March 20, 2003

Inventors: Mohammed N. Islam, Michael J. Freeman

Publication number: 20030053192

Abstract: A Raman amplifier includes a Raman gain fiber comprising a length of high-dispersion gain fiber and operable to receive at least one optical signal. The Raman amplifier also includes at least one pump source capable of generating at least one pump signal that co-propagates within the Raman gain fiber with at least a portion of the at least one optical signal received by the Raman gain fiber. The length of the high-dispersion gain fiber is at least ten (10) times a walk off length between the at least one pump signal and at least one wavelength of the at least one optical signal received by the Raman gain fiber. In addition, the length of high-dispersion gain fiber is at least two (2) times a walk off length between at least two optical signal wavelengths of the at least one optical signal received by the Raman gain fiber.

Type: Application

Filed: August 2, 2002

Publication date: March 20, 2003

Inventors: Mohammed N. Islam, Michael J. Freeman

Patent number: 6532101

Abstract: A multi-stage Raman amplifier includes a first Raman amplifier stage having a first sloped gain profile operable to amplify a plurality of signal wavelengths, and a second Raman amplifier stage having a second sloped gain profile operable to amplify at least most of the plurality of signal wavelengths after those wavelengths have been amplified by the first stage. The second sloped gain profile is approximately complementary slope to the slope of the first sloped gain profile. The combined effect of the first and second Raman stages contributes to an approximately flat overall gain profile over the plurality of signal wavelengths.

Type: Grant

Filed: March 16, 2001

Date of Patent: March 11, 2003

Assignee: Xtera Communications, Inc.

Inventors: Mohammed N. Islam, Carl A. Dewilde, Michael J. Freeman