摘要:
Dynamically reconfigurable holograms with electronically erasable programmable intermediate layers are disclosed. An example apparatus includes first nanowires, each of the first nanowires having protuberances along a length thereof. The example apparatus also includes second nanowires arranged approximately perpendicular to the first nanowires, the protuberances of the first nanowires being approximately parallel to corresponding ones of the second nanowires. In addition, a layer is disposed between the first and second nanowires. The layer is to control refractive indices at nanowire intersections at intersecting ones of the first and second nanowires.
摘要:
A light-emitting diode (LED) (101). The LED (101) includes a plurality of portions including a p-doped portion (112), an intrinsic portion (114), and a n-doped portion (116). The intrinsic portion (114) is disposed between the p-doped portion (112) and the n-doped portion (116) and forms a p-i junction (130) and an i-n junction (134) The LED (101) also includes a metal-dielectric-metal (MDM) structure (104) including a first metal layer (140), a second metal layer (144), and a dielectric medium disposed between the first metal layer (140) and the second metal layer (144). The metal layers of the MDM structure (104) are disposed about orthogonally to the p-i junction (130) and the i-n junction (134); the dielectric medium includes the intrinsic portion (114); and, the MDM structure (104) is configured to enhance modulation frequency of the LED (101) through interaction with surface plasmons that are present in the metal layers.
摘要:
Various embodiments of the present invention are directed to external, electronically controllable, negative index material-based modulators. In one aspect, an external modulator comprises a negative index material in electronic communication with an electronic signal source. The negative index material receives an electronic signal encoding data from the electronic signal source and an unmodulated carrier wave from an electromagnetic radiation source. Magnitude variations in the electronic signal produce corresponding effective refractive index changes in the negative index material encoding the data in the amplitude and/or phase of the carrier wave to produce an electromagnetic signal.
摘要:
One embodiment of the present invention relates to a light-emitting diode having one or more light-emitting layers, a pair of electrodes disposed on the light-emitting diode so that an operating voltage can be applied to generate light from the one or more light-emitting layers, and at least one external electrode in electronic communication with the one or more light-emitting layers. Applying an appropriate voltage to the at least one external electrodes at about the time the operating voltage is terminated extracts excess electrons from the one or more light-emitting layers and reduces the duration of electron-hole recombination during the time period over which the operating voltage is turned off.
摘要:
Nanowire-based opto-electronic devices including nanowire lasers, photodetectors and semiconductor optical amplifiers are disclosed. The devices include nanowires grown from single crystal and/or non-single surfaces. The semiconductor optical amplifiers include nanowire arrays that act as ballast lasers to amplify a signal carried by a signal waveguide. Embodiments of the nanowire lasers and photodetectors include horizontal and vertical nanowires that can provide different polarizations.
摘要:
A memristive device includes a first electrode and a second electrode crossing the first electrode at a non-zero angle. An active region is disposed between the first and second electrodes. The active region has defects therein. Graphene or graphite is disposed between the active region and the first electrode and/or between the active region and the second electrode.
摘要:
A photovoltaic structure (100), a solar cell (100, 200) and a method (300) of fabricating a solar cell (100, 200) employ a hidden electrode (122, 222, 422) on a formed (320) mesa (120, 220, 420) and a bramble (130, 230, 430) of grown (330) nanowires. The mesa includes an insulator island (121, 221, 421) adjacent to a surface of the substrate (110, 210, 410) and the hidden electrode buried under a seed layer on the insulator island. One end of some of the nanowires (134, 234) is anchored to the seed layer (124, 224, 424) of the mesa. One end of others of the nanowires (132, 232) is anchored to a seed layer (114, 214, 414) formed (310) on the substrate adjacent to the mesa. The seed layers independently are an extrinsic semiconductor. A semiconductor junction includes the seed layers and some of the nanowires of the bramble.
摘要:
A free-space optical communication system includes a detector array having a plurality of detector elements and a transmitting source. Dynamic movement of the optical signal on the detector array is caused by changes in orientation of the transmitting source. A tracker tracks the movement of the optical signal in real-time on the detector array. An output signal is derived from at least one of the detector elements illuminated by the optical signal.
摘要:
Beam couplers and splitters are disclosed herein. An embodiment of a beam coupler and splitter includes a first waveguide including a bevel and a bend, and a second waveguide including a bevel complementarily shaped to the first waveguide bevel. The first waveguide bevel is configured to totally internally reflect at least some light incident thereon. The second waveguide is coupled to the first waveguide such that i) the second waveguide bevel is adjacent to at least a portion of the first waveguide bevel, and ii) a predetermined coupling ratio is achieved.
摘要:
A patterned array of metallic nanostructures and fabrication thereof is described. A device comprises a patterned array of metallic columns vertically extending from a substrate. Each metallic column is formed by metallically coating one of an array of non-metallic nanowires catalytically grown from the substrate upon a predetermined lateral pattern of seed points placed thereon according to a nanoimprinting process. An apparatus for fabricating a patterned array of metallic nanostructures is also described.