Patents by Inventor Jonathan R. Birge
Jonathan R. Birge has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7433043Abstract: The phase spectrum of an ultrashort pulse is measured based on two-dimensional spectral shearing interferometry with zero delay. The measurement is performed utilizing an optical source pulse from which is extracted a short pulse and from which a chirped component is generated. The chirped component is split into first and second chirped pulses. The first and second pulses are then mixed with the short pulse in a nonlinear medium to produce up-converted and spectrally sheared copies of the first and second chirped pulses, which are measured in a spectrometer. A plurality of path lengths for the first second chirped pulses is provided to shift the relative phases of the first and second chirped pulses for additional measurements. The apparatus and methods are uniquely suited for characterizing single-cycle pulses.Type: GrantFiled: December 8, 2006Date of Patent: October 7, 2008Assignee: Massachusetts Institute of TechnologyInventors: Jonathan R. Birge, Richard Ell, Franz X. Kaertner
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Patent number: 7154667Abstract: A birefringent network can be formed from a pair of beam directing elements that sandwich a birefringent filter. One of the beam director elements can be a polarizing beam splitter and the other of the beam director elements can be a reflector or polarizing beam splitter. The polarizing beam splitters can be formed by an anisotropic material sandwiched between two isotropic pieces and can include optical films to couple both polarizations of light into and out of the beam splitters. The polarizing beam splitters also can be formed by anisotropic material on either side of an isotropic bow-tie piece, all of which is sandwiched a pair of isotropic pieces. A birefringent network also can be formed by a pair of bulk birefringent beam splitters sandwiching a birefringent filter. Little or no polarization mode dispersion occurs in these birefringent networks since all of the beams travel the same distances through the same elements.Type: GrantFiled: September 2, 2003Date of Patent: December 26, 2006Assignee: ColorLink, Inc.Inventors: Jonathan R. Birge, Gary D. Sharp
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Patent number: 7002752Abstract: The present application describes color management architecture for a three-panel projection system that utilizes color selective polarization filters (CSPF) and polarizing beam splitting elements. An exemplary embodiment describes a color management architecture with a dichroic input beam splitter and three polarizing beam splitters. An output polarizing beam splitter is used as an analyzer. The color management system architecture can isolate any color channel from those remaining whose separation and combination are then carried out by a single beamsplitting element. The disclosed embodiments also provide an improvement in the ANSI contrast. In some embodiments, an achromatic quarter-wave plate is used in combination with a color filter to block the light reflected from projection optics.Type: GrantFiled: November 14, 2003Date of Patent: February 21, 2006Assignee: ColorLink, Inc.Inventors: Jianmin Chen, Michael G. Robinson, Gary D. Sharp, Jonathan R. Birge
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Patent number: 6961181Abstract: Beamsplitters are frequently used in projectors based on reflective liquid crystal display for separating input and output light, and more recently for color management systems. Rather stack filters are used in such systems to orthogonally polarize primary colors, converting polarizing beamsplitters to color splitters and combiners. Geometric polarization rotations induced by beamsplitters at moderate f-numbers have the effect of significantly degrading performance. Because retarder stacks in general rely on a specific input polarization to perform properly, such skew rays are responsible for color cross-talk. Retarder stacks designed according to the present invention are sensitive to the symmetries that exist between input and output polarizer configurations. These stacks provide the polarization transformations that will compensate for skew rays, such that normal incidence performance is maintained for all incident light.Type: GrantFiled: May 5, 2004Date of Patent: November 1, 2005Assignee: ColorLink, Inc.Inventors: Jianmin Chen, Michael G. Robinson, Jonathan R. Birge, Gary D. Sharp
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Patent number: 6961179Abstract: Disclosed are color management architectures used in video projection systems including, for example, retarder stacks sensitive to the symmetries between input and output polarizer configurations that provide the polarization transformations that will comprise for skew rays, such that normal incidence performance is maintained for all incident light. Additionally, also disclosed are systems that utilize color selective polarization (CSP) filters and polarizing beam splitting elements such that an output analyzer is not required. One exemplary CSP architecture includes two CSPs, a single polarizing beam splitting element combination for splitting and combining light between two of the three panels, and an output polarizing beam splitting element used as an analyzer such that a single CSP is in the projection path.Type: GrantFiled: November 14, 2002Date of Patent: November 1, 2005Assignee: Colorlink, Inc.Inventors: Jianmin Chen, Michael G. Robinson, Gary D. Sharp, Jonathan R. Birge
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Patent number: 6816309Abstract: Beamsplitters are frequently used in projectors based on reflective liquid crystal displays for separating input and output light, and more recently for color management systems. Retarder stack filters are used in such systems to orthogonally polarize primary colors, converting polarizing beamsplitters to color splitters and combiners. Geometric polarization rotations induced by beamsplitters at moderate f-numbers have the effect of significantly degrading performance. Because retarder stacks in general rely on a specific input polarization to perform properly, such skew rays are responsible for color cross-talk. Retarder stacks designed according to the present invention are sensitive to the symmetries that exit between input and output polarizer configurations. These stacks provide the polarization transformations that will compensate for skew rays, such that normal incidence performance is maintained for all incident light.Type: GrantFiled: November 30, 2001Date of Patent: November 9, 2004Assignee: ColorLink, Inc.Inventors: Jianmin Chen, Michael G. Robinson, Jonathan R. Birge, Gary D. Sharp
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Publication number: 20040207919Abstract: Beamsplitters are frequently used in projectors based on reflective liquid crystal display for separating input and output light, and more recently for color management systems. Rather stack filters are used in such systems to orthogonally polarize primary colors, converting polarizing beamsplitters to color splitters and combiners. Geometric polarization rotations induced by beamsplitters at moderate f-numbers have the effect of significantly degrading performance. Because retarder stacks in general rely on a specific input polarization to perform properly, such skew rays are responsible for color cross-talk. Retarder stacks designed according to the present invention are sensitive to the symmetries that exist between input and output polarizer configurations. These stacks provide the polarization transformations that will compensate for skew rays, such that normal incidence performance is maintained for all incident light.Type: ApplicationFiled: May 5, 2004Publication date: October 21, 2004Inventors: Jianmin Chen, Michael G. Robinson, Jonathan R. Birge, Gary D. Sharp
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Publication number: 20040136067Abstract: The present application describes color management architecture for a three-panel projection system that utilizes color selective polarization filters (CSPF) and polarizing beam splitting elements. An exemplary embodiment describes a color management architecture with a dichroic input beam splitter and three polarizing beam splitters. An output polarizing beam splitter is used as an analyzer. The color management system architecture can isolate any color channel from those remaining whose separation and combination are then carried out by a single beamsplitting element. The disclosed embodiments also provide an improvement in the ANSI contrast. In some embodiments, an achromatic quarter-wave plate is used in combination with a color filter to block the light reflected from projection optics.Type: ApplicationFiled: November 14, 2003Publication date: July 15, 2004Inventors: Jianmin Chen, Michael G. Robinson, Gary D. Sharp, Jonathan R. Birge
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Patent number: 6704065Abstract: An optical system divides a light source into its component color bands red, green and blue by making the light travel different physical paths, at least two of these paths use stack retardation films and a polarization beamsplitter. By creating distinct paths, each code can be independently processed and combined to form a single path using a polarization splitter and retarder stack. The system preferably includes an input retarder that aligns a first spectrum of a light from a light source, along a first polarization state, and aligns a second spectrum of the light from the light source, along a second polarization state different than the first polarization state, and a beam splitting unit, optically coupled to the input retarder, and including a first beamsplitter that transmits the first spectrum, as a transmitted spectrum, and that reflects the second spectrum, as a reflected spectrum.Type: GrantFiled: May 12, 2000Date of Patent: March 9, 2004Assignee: Colorlink, Inc.Inventors: Gary D. Sharp, Michael G. Robinson, Jonathan R. Birge
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Publication number: 20040042077Abstract: A birefringent network can be formed from a pair of beam directing elements that sandwich a birefringent filter. One of the beam director elements can be a polarizing beam splitter and the other of the beam director elements can be a reflector or polarizing beam splitter. The polarizing beam splitters can be formed by an anisotropic material sandwiched between two isotropic pieces and can include optical films to couple both polarizations of light into and out of the beam splitters. The polarizing beam splitters also can be formed by anisotropic material on either side of an isotropic bow-tie piece, all of which is sandwiched a pair of isotropic pieces. A birefringent network also can be formed by a pair of bulk birefringent beam splitters sandwiching a birefringent filter. Little or no polarization mode dispersion occurs in these birefringent networks since all of the beams travel the same distances through the same elements.Type: ApplicationFiled: September 2, 2003Publication date: March 4, 2004Inventors: Jonathan R. Birge, Gary D. Sharp
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Publication number: 20030227680Abstract: Beamsplitters are used in projectors with retarder stack filters to orthogonally polarize primary colors, converting polarizing beamsplitters to color splitters and combiners. Geometric polarization rotations induced by beamsplitters at moderate f-numbers significantly degrading performance. Because retarder stacks may rely on a specific input polarization to perform properly, such skew rays result in color cross-talk. Retarder stacks according to the present invention are sensitive to the symmetries between input and output polarizer configurations. These stacks provide the polarization transformations that will compensate for skew rays, such that normal incidence performance is maintained for all incident light. Additionally, systems that utilize color selective polarization filters (CSP) and polarizing beam splitting elements such that an output analyzer is not required are disclosed. The CSP may be included in the above system.Type: ApplicationFiled: November 14, 2002Publication date: December 11, 2003Inventors: Jianmin Chen, Michael G. Robinson, Gary D. Sharp, Jonathan R. Birge
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Publication number: 20030107809Abstract: Beamsplitters are frequently used in projectors based on reflective liquid crystal displays for separating input and output light, and more recently for color management systems. Retarder stack filters are used in such systems to orthogonally polarize primary colors, converting polarizing beamsplitters to color splitters and combiners. Geometric polarization rotations induced by beamsplitters at moderate f-numbers have the effect of significantly degrading performance. Because retarder stacks in general rely on a specific input polarization to perform properly, such skew rays are responsible for color cross-talk. Retarder stacks designed according to the present invention are sensitive to the symmetries that exit between input and output polarizer configurations. These stacks provide the polarization transformations that will compensate for skew rays, such that normal incidence performance is maintained for all incident light.Type: ApplicationFiled: November 30, 2001Publication date: June 12, 2003Inventors: Jianmin Chen, Michael G. Robinson, Jonathan R. Birge, Gary D. Sharp