Patents by Inventor David Graham Moodie
David Graham Moodie 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: 8809092Abstract: A method of generating radiation comprises: manufacturing a structure comprising a substrate supporting a layer of InGaAs, InGaAsP, or InGaAlAs material doped with a dopant, said manufacturing comprising growing said layer such that said dopant is incorporated in said layer during growth of the layer; illuminating a portion of a surface of the structure with radiation having photon energies greater than or equal to a band gap of the doped InGaAs, InGaAsP, or InGaAlAs material so as to create electron-hole pairs in the layer of doped material; and accelerating the electrons and holes of said pairs with an electric field so as to generate radiation. In certain embodiments the dopant is Fe. Corresponding radiation detecting apparatus, spectroscopy systems, and antennas are described.Type: GrantFiled: July 19, 2010Date of Patent: August 19, 2014Inventors: Edmund Linfield, John Cunningham, Alexander Giles Davies, Christopher Wood, Paul John Cannard, David Graham Moodie, Xin Chen, Michael James Robertson
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Publication number: 20120113417Abstract: A method of generating radiation comprises: manufacturing a structure comprising a substrate supporting a layer of InGaAs, InGaAsP, or InGaAlAs material doped with a dopant, said manufacturing comprising growing said layer such that said dopant is incorporated in said layer during growth of the layer; illuminating a portion of a surface of the structure with radiation having photon energies greater than or equal to a band gap of the doped InGaAs, InGaAsP, or InGaAlAs material so as to create electron-hole pairs in the layer of doped material; and accelerating the electrons and holes of said pairs with an electric field so as to generate radiation. In certain embodiments the dopant is Fe. Corresponding radiation detecting apparatus, spectroscopy systems, and antennas are described.Type: ApplicationFiled: July 19, 2010Publication date: May 10, 2012Inventors: Edmund Linfield, John Cunningham, Alexander Giles Davies, Christopher Wood, Paul John Cannard, David Graham Moodie, Xin Chen, Michael James Robertson
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Publication number: 20100215308Abstract: An electroabsorption modulator comprises an absorption layer, at least one layer of p-doped semiconductor, and at least one layer of n-doped semiconductor, said absorption layer being provided between said at least one layer of p-doped semiconductor and said at least one layer of n-doped semiconductor, and said layers forming a ridge waveguide structure, wherein the thickness of said absorption layer is between 9 and 60 nm, the width of said absorption layer is between 4.5 and 12 microns, and the width of at least one of said at least one layer of p-doped semiconductor and said at least one layer of n-doped semiconductor is between 4.5 and 12 microns; whereby the width of said ridge waveguide structure is between 4.5 and 12 microns.Type: ApplicationFiled: March 10, 2010Publication date: August 26, 2010Applicant: THE CENTRE FOR INTEGRATED PHOTONICS LIMITEDInventor: David Graham Moodie
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Patent number: 7709799Abstract: A detector for electromagnetic radiation in the range 80 GHz to 4 THz comprises a laser light source (115) an optical modulator (13) arranged to modulate light from the laser light source (11) and a filter system (17) for selecting a defined range of frequencies of the modulated light. The optical modulator is an electroabsorption modulator (13) with an antenna (15) which is sensitive to electromagnetic radiation in the range 80 GHz to 4 THz. The signal received by the antenna (15) modulates the electric field across the electroabsorption modulator (13), whereby to modulate the light from the laser light source (11).Type: GrantFiled: May 18, 2006Date of Patent: May 4, 2010Assignees: The Centre For Integrated Photonics Limited, University of EssexInventors: David Graham Moodie, Michael James Robertson, Ian Douglas Henning
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Publication number: 20090206262Abstract: A detector for electromagnetic radiation in the range 80 GHz to 4 THz comprises a laser light source (115) an optical modulator (13) arranged to modulate light from the laser light source (11) and a filter system (17) for selecting a defined range of frequencies of the modulated light. The optical modulator is an electroabsorption modulator (13) with an antenna (15) which is sensitive to electromagnetic radiation in the range 80 GHz to 4 THz. The signal received by the antenna (15) modulates the electric field across the electroabsorption modulator (13), whereby to modulate the light from the laser light source (11).Type: ApplicationFiled: May 18, 2006Publication date: August 20, 2009Inventors: David Graham Moodie, Michael James Robertson, Ian Douglas Henning
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Publication number: 20030095751Abstract: An optical monomode guided-wave device, especially an electroabsorption modulator, having an active region with a mode size small compared with that of an optical fibre is integrated with at least one passive spot size adjuster which has an optical core that tapers simultaneously from a width and height substantially equal to those of the active region adjacent to that region to a width large compared with the width of the active region and a thickness substantially smaller than the thickness of the active region at a position remote from that region. Usually—unless the device includes its own light source—there will be two spot size adjusters, respectively at the inlet and outlet of the device.Type: ApplicationFiled: November 15, 2002Publication date: May 22, 2003Inventors: David Carnegie Rogers, David Graham Moodie, Ian Francis Lealman, Simon David Perrin
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Patent number: 6396604Abstract: An optical network includes a number of nodes coupled to an optical transmission medium, such as an optical fiber bus. Each of the nodes includes a dark pulse generator. Different nodes output dark pulses in different time slots onto the transmission medium, forming a dark pulse OTDM (optical time division multiplexed) signal. The network may have a re-entrant bus topology.Type: GrantFiled: March 19, 1998Date of Patent: May 28, 2002Assignee: British Telecommunications plcInventors: Kevin Smith, Julian Kazimierz Lucek, Danny Robert Pitcher, Terrence Widdowson, David Graham Moodie, Andrew David Ellis
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Patent number: 6208672Abstract: An optical pulse source includes a gain-switched semiconductor laser diode. Light from a continuous wave source is opitically coupled into the laser cavity. Light output from the laser cavity passes through an electro-optic amplitude modulator. Synchronized modulating signals are applied to the semiconductor diode and to the amplitude modulator. The source outputs short low-jitter low-pedestal optical pulses and is suitable for use, for example, in a broadband optical network operating at thigh bit rates of 100 Gbit/s or more, or in an optical interconnect.Type: GrantFiled: March 23, 1998Date of Patent: March 27, 2001Assignee: British Telecommunications public limited companyInventors: Paul Gunning, Kevin Smith, Davey Russell, Julian Kazimierz Lucek, David Graham Moodie, Derek Nesset
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Patent number: 6008926Abstract: A discrete electroabsorption modulator for optical signals has an electrical blocking region (12a, 12b) which is large as compared with the absorber region (13). The height of the blocking region (12a, 12b) is 3-20 .mu.m, e.g. 4-6 .mu.m and preferably about 5 .mu.m. In addition, the blocking region (12a, 12b) is 2-250 times, e.g. 15-25 times the height of the absorber region (13). The modulation depth is substantially increased, e.g. to values above 40 dB, by a thick electrical blocking region. It is believed that the thick blocking layer (12a, 12b) works because parasitic signals which escape into the blocking region are spatially removed from the vicinity of the absorber region; thus they are not acquired at the output.Type: GrantFiled: March 11, 1998Date of Patent: December 28, 1999Assignee: British Telecommunications public limited companyInventors: David Graham Moodie, Michael John Harlow
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Patent number: 5778015Abstract: An optical pulse source includes a gain-switched semiconductor laser diode (1). Light from a continuous wave source (3) is optically coupled into the laser cavity. Light output from the laser cavity passes through an electro-optic amplitude modulator (2). Synchronised modulating signals are applied to the semiconductor diode and to the amplitude modulator. The source outputs short low-jitter optical pulses and is suitable for use, for example, in a broadband optical network operating at high bit rates of 100 Gbit/s or more, or in an optical interconnect.Type: GrantFiled: May 16, 1996Date of Patent: July 7, 1998Assignee: British Telecommunications public limited companyInventors: Paul Gunning, Russell Davey, David Graham Moodie, Kevin Smith, Julian Lucek, Derek Nesset