Patent application number | Description | Published |
20110111564 | METHOD AND APPARATUS FOR OPTICAL MODULATION - The present invention is a method and an apparatus for optical modulation, for example for use in optical communications links. In one embodiment, an apparatus for optical modulation includes a first silicon layer having one or more trenches formed therein, a dielectric layer lining the first silicon layer, and a second silicon layer disposed on the dielectric layer and filling the trenches. | 05-12-2011 |
20120205523 | AVALANCHE IMPACT IONIZATION AMPLIFICATION DEVICES - A semiconductor photodetector may provide charge carrier avalanche multiplication at high field regions of a semiconductor material layer. A semiconductor current amplifier may provide current amplification by impact ionization near a high field region. A plurality of metal electrodes are formed on a surface of a semiconductor material layer and electrically biased to produce a non-uniform high electric field in which the high electric field strength accelerates avalanche electron-hole pair generation, which is employed as an effective avalanche multiplication photodetection mechanism or as an avalanche impact ionization current amplification mechanism. | 08-16-2012 |
20120326012 | AVALANCHE IMPACT IONIZATION AMPLIFICATION DEVICES - A semiconductor photodetector may provide charge carrier avalanche multiplication at high field regions of a semiconductor material layer. A semiconductor current amplifier may provide current amplification by impact ionization near a high field region. A plurality of metal electrodes are formed on a surface of a semiconductor material layer and electrically biased to produce a non-uniform high electric field in which the high electric field strength accelerates avalanche electron-hole pair generation, which is employed as an effective avalanche multiplication photodetection mechanism or as an avalanche impact ionization current amplification mechanism. | 12-27-2012 |
20130015375 | GENERATION OF TERAHERTZ ELECTROMAGNETIC WAVES IN GRAPHENE BY COHERENT PHOTON-MIXINGAANM AVOURIS; PHAEDONAACI Yorktown HeightsAAST NYAACO USAAGP AVOURIS; PHAEDON Yorktown Heights NY USAANM Sung; Chun-YungAACI PoughkeepsieAAST NYAACO USAAGP Sung; Chun-Yung Poughkeepsie NY USAANM Valdes Garcia; AlbertoAACI HartsdaleAAST NYAACO USAAGP Valdes Garcia; Alberto Hartsdale NY USAANM Xia; FengnianAACI PlainsboroAAST NJAACO USAAGP Xia; Fengnian Plainsboro NJ US - An electromagnetic device and method for fabrication includes a substrate and a layer of graphene formed on the substrate. A metallization layer is patterned on the graphene. The metallization layer forms electrodes such that when the graphene is excited by light, terahertz frequency radiation is generated. | 01-17-2013 |
20130134391 | Reducing Contact Resistance for Field-Effect Transistor Devices - A method and an apparatus for doping a graphene and nanotube thin-film transistor field-effect transistor device to decrease contact resistance with a metal electrode. The method includes selectively applying a dopant to a metal contact region of a graphene and nanotube field-effect transistor device to decrease the contact resistance of the field-effect transistor device. | 05-30-2013 |
20130143335 | METHOD AND APPARATUS FOR OPTICAL MODULATION - The present invention is a method and an apparatus for optical modulation, for example for use in optical communications links. In one embodiment, an apparatus for optical modulation includes a first silicon layer having one or more trenches formed therein, a dielectric layer lining the first silicon layer, and a second silicon layer disposed on the dielectric layer and filling the trenches. | 06-06-2013 |
20130333937 | GRAPHENE BASED STRUCTURES AND METHODS FOR SHIELDING ELECTROMAGNETIC RADIATION - Electromagnetic interference shielding structures and methods of shielding an object form electromagnetic radiation at frequencies greater than a megahertz generally include providing highly doped graphene sheets about the object to be shielded. The highly doped graphene sheets may have a dopant concentration greater than >1e10 | 12-19-2013 |
20130334472 | GRAPHENE BASED STRUCTURES AND METHODS FOR SHIELDING ELECTROMAGNETIC RADIATION - Electromagnetic interference shielding structures and methods of shielding an object form electromagnetic radiation at frequencies greater than a megahertz generally include providing doped graphene sheets about the object to be shielded. The doped graphene sheets have a dopant concentration that is effective to reflect and/or absorb the electromagnetic radiation. | 12-19-2013 |
20130335254 | GRAPHENE BASED STRUCTURES AND METHODS FOR BROADBAND ELECTROMAGNETIC RADIATION ABSORPTION AT THE MICROWAVE AND TERAHERTZ FREQUENCIES - Structures and methods for cloaking an object to electromagnetic radiation at the microwave and terahertz frequencies include disposing a plurality of graphene sheets about the object. Intermediate layers of a transparent dielectric material can be disposed between graphene sheets to optimize the performance. In other embodiments, the graphene can be formulated into a paint formulation or a fabric and applied to the object. The structures and methods absorb at least a portion of the electromagnetic radiation at the microwave and terabyte frequencies. | 12-19-2013 |
20130335255 | GRAPHENE BASED STRUCTURES AND METHODS FOR BROADBAND ELECTROMAGNETIC RADIATION ABSORPTION AT THE MICROWAVE AND TERAHERTZ FREQUENCIES - Structures and methods for cloaking an object to electromagnetic radiation at the microwave and terahertz frequencies include disposing a plurality of graphene sheets about the object. Intermediate layers of a transparent dielectric material can be disposed between graphene sheets to optimize the performance. In other embodiments, the graphene can be formulated into a paint formulation or a fabric and applied to the object. The structures and methods absorb at least a portion of the electromagnetic radiation at the microwave and terabyte frequencies. | 12-19-2013 |
20140332757 | GRAPHENE PHOTODETECTOR - A set of buried electrodes are embedded in a dielectric material layer, and a graphene layer having a doping of a first conductivity type are formed thereupon. A first upper electrode is formed over a center portion of each buried electrode. Second upper electrodes are formed in regions that do not overlie the buried electrodes. A bias voltage is applied to the set of buried electrodes to form a charged region including minority charge carriers over each of the buried electrodes, and to form a p-n junction around each portion of the graphene layer overlying a buried electrode. Charge carriers generated at the p-n junctions are collected by the first upper electrodes and the second upper electrodes, and are subsequently measured by a current measurement device or a voltage measurement device. | 11-13-2014 |
20140335650 | GRAPHENE PHOTODETECTOR - A set of buried electrodes are embedded in a dielectric material layer, and a graphene layer having a doping of a first conductivity type are formed thereupon. A first upper electrode is formed over a center portion of each buried electrode. Second upper electrodes are formed in regions that do not overlie the buried electrodes. A bias voltage is applied to the set of buried electrodes to form a charged region including minority charge carriers over each of the buried electrodes, and to form a p-n junction around each portion of the graphene layer overlying a buried electrode. Charge carriers generated at the p-n junctions are collected by the first upper electrodes and the second upper electrodes, and are subsequently measured by a current measurement device or a voltage measurement device. | 11-13-2014 |