Abstract: An approach is provided that uses diversity to compensate fading of free-space optical (FSO) signals propagating through an environment characterized by atmospheric scintillation. One embodiment involves collecting at least one FSO beam, demultiplexing the beam by wavelength into at least two sub-beams, detecting each sub-beam to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. Another embodiment involves collecting the FSO beam onto an array of spatially separated sub-apertures, detecting the light entering each sub-aperture to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. This second embodiment enables both electronic adaptive processing to coherently integrate across the sub-apertures and in the case of multiple transmit apertures a free space optical Multiple Input Multiple Output (MIMO) system.

Abstract: There is provided a method for forming a graphene layer. The method includes forming an article that comprises a carbon-containing self-assembled monolayer (SAM). A layer of nickel is deposited on the SAM. The article is heated in a reducing atmosphere and coolded. The heating and cooling steps are carried out so as to convert the SAM to a graphene layer.

Abstract: A chemical sensor is provided. The sensor includes at least one lightguiding element having an optical core. The lightguiding element comprises a layer of graphene situated in sufficient proximity to the core to exhibit evanescent wave absorption of optical energy in at least one optical mode guided in the core.

Abstract: A method and system for compensating for frequency dependent phase and amplitude imbalances is provided. A plurality of frequency sub-bands is extracted from a received wideband signal. Each of the plurality of frequency sub-bands is compensated to produce an associated plurality of compensated frequency sub-bands. The compensated sub-bands are summed in order to produce a compensated signal.

Abstract: A deposition apparatus comprising a vaporizer chamber configured to hold a solid precursor of a dopant element therein. Gas input and output lines are connected to the vaporizer chamber and flow rate controllers are coupled to each of the gas input and output lines. The flow rate controllers are configured to adjust a rate of carrier gas flow into and out of the vaporizer chamber through the gas input and output lines. The vaporizer chamber has a temperature controller and pressure controller to produce vapors of the solid precursor in the vaporizer chamber that can be carried with the carrier gas flow through the output line.

Abstract: An apparatus comprising a dispersion plate, a dispersion plate, the dispersion plate including input side openings connected to holes therein, the holes following a torturous path through the dispersion plate and configured to deliver dopants through output side openings of the dispersion plate.

Abstract: Various embodiments provide a method and apparatus for providing queries in an information-centric network. In particular, the content is identified by a name that includes discrete components that identify the participating caching nodes within a network. Caching nodes store a reference to the content and are configured to provide the address of the node(s) providing the requested content.

Abstract: An apparatus includes a gas dispersal plate and an adapter structure. The gas dispersal plate has a plurality of gas dispersion orifices, wherein one or more of the gas dispersion orifices have a first portion with a first cross-section configured to allow entry of gas and a second portion having a second cross-section configured to allow exit of gas, the first cross-section being smaller than the second cross-section.

Abstract: An antenna comprises a ring-shaped radiofrequency resonator that defines a path for a circulating magnetic current. In an implementation, the resonator has a height of no more than 2% of an operating wavelength, and it has an electromagnetic resonance at the operating frequency. In an implementation, the antenna is of a type having a vertical, short electric dipole radiation or sensitivity pattern. It comprises, as the dominant radiative element, a ring of material disposed transverse to the vertical dipole axis and having an average magnetic permeability more than ten times the magnetic permeability of air. The ring has a maximum outer diameter and a height that is less than the maximum outer diameter. The antenna further includes a feed structure adapted to couple radiofrequency energy into and/or out of a magnetic current circulating in the ring.

Abstract: An apparatus transmits data using a format where information bits intended for transmission are mapped into symbols each carrying a plurality of bits, some of which are encoded through pulse position modulation (PPM) format and the rest of which are encoded through an additional modulation format on each PPM pulse. The additional modulation format for the PPM pulse may be at least one of a polarization-division-multiplexed (PDM) modulation, phase-shift keying (PSK) modulation, polarization shift keying (PolSK) modulation, amplitude modulation (AM), quadrature-amplitude modulation (QAM) modulation, or a combination thereof. In one embodiment, the additional modulation of the PPM pulses is through polarization-division-multiplexed quadrature-phase-shift keying (PDM-QPSK). The unique combined use of PDM-QPSK and PPM produces much higher receiver sensitivity than either PPM or PDM-QPSK alone.

Abstract: An apparatus receives data encoded in a format where information bits for transmission are mapped into symbols each carrying a plurality of bits, some being encoded through a pulse position modulation (PPM) format and some being encoded through an additional modulation format on at least one PPM pulse. A receiver detects the signal through a dual-polarization coherent receiver front-end, recovering polarization components of the signal by decoding a first non-zero portion of a plurality of bits carried by a symbol based on slot position of at least one PPM pulse in the polarization components and a second non-zero portion of the plurality of bits carried by the symbol based on the additional modulation carried by at least one PPM pulse in the polarization components. Pilot-assisted single-carrier frequency-division equalization (PA-SC-FDE) may be used for reliable signal reception in the presence of severe PPM errors.

Abstract: A method of beamforming a radiofrequency array having multiple antenna elements is provided. The method includes transmitting two or more sub-beams of a modulated light beam through a switched fabric, using wavelength switching to designate a respective path through the switched fabric for each sub-beam, and converting each sub-beam to a driving signal for one or more of the antenna elements or to a received signal from one or more of the antenna elements. Each path through the switched fabric has a selected cumulative true time delay.

Abstract: An optical assembly is provided that can mitigate thermal damage that could otherwise occur in the region near where the optical fiber emerges from a high-power optical device package. The optical assembly includes an optical medium to guide stray light, along the fiber axis but substantially outside of the fiber core, from the interior to the exterior of a housing. The assembly further includes a transition region external to the housing, where at least one optical mode guided by the optical medium transitions to at least one optical mode confined by a polymer coating as a guided mode of the cladding. In embodiments, the optical medium is provided by the fiber cladding together with overlying materials of relatively low refractive index that help to confine the stray light within the cladding.

Abstract: A system for testing a communications network includes a controller having a computing device with a controller application and an operator having a microcontroller and a device interface module controlled by the microcontroller. A handheld communications device is operatively connected to the operator through the device interface module and adapted to communicate over the communications network being tested. The controller and the operator are connected by an out-of-band wireless control link to allow communication therebetween outside of the communications network being tested. The operator is adapted to receive commands from the controller over the out-of-band control link and, upon receipt of a command from the controller over the out-of-band control link, to initiate in-band communication on the handheld communications device over the communications network through the device interface module.

Abstract: A composite dielectric material having a plurality of particle cores, each surrounded by polymer strands that are chemically bonded to the surface of the particle core. Each polymer strand includes a linker, through which the polymer strand is attached to the surface, an interfacial core-shielding (ICS) group bound to the linker, and a polymer molecule bound to the ICS group. The ICS groups are designed to inhibit electrical breakdown of the composite dielectric material by (i) deflecting or scattering free electrons away from the particle cores and/or (ii) capturing free electrons by being transformed into relatively stable radical anions. Representative examples of the particle core material, linker, ICS group, and polymer molecule are titanium dioxide, a phosphonate group, a halogenated aromatic ring, and a polystyrene molecule, respectively.

Abstract: An optical amplifier comprises at least two gain regions, an intermediate region situated between the gain regions, and a transition region situated between the intermediate region and each gain region. The aforesaid regions have claddings that collectively form a path for pump radiation propagating from at least one of the gain regions to the other gain region, and cores that collectively form a path for signal radiation propagating from at least one of the gain regions to the other gain region. The cores in the gain regions support multiple propagating optical modes, including at least one signal mode and at least one non-signal mode. The intermediate region, however, supports fewer propagating core modes than are supported by the gain regions. The transition regions are conformed such that when radiation in propagating non-signal core modes passes from the gain regions into the intermediate region, it is at least partly coupled into cladding modes of the intermediate region.

Abstract: A method and system for compensating for frequency dependent phase and amplitude imbalances is provided. A plurality of frequency sub-bands is extracted from a received wideband signal. Each of the plurality of frequency sub-bands is compensated to produce an associated plurality of compensated frequency sub-bands. The compensated sub-bands are summed in order to produce a compensated signal.

Abstract: A method and system for transmitting alerts messages is provided. An automatic management system determines a location of a device. An alerting device is determined based on the determined location and an alert message is transmitted to the alerting device.

Abstract: A composite dielectric material having a plurality of particle cores, each surrounded by polymer strands that are chemically bonded to the surface of the particle core. Each polymer strand includes a linker, through which the polymer strand is attached to the surface, an interfacial core-shielding (ICS) group bound to the linker, and a polymer molecule bound to the ICS group. The ICS groups are designed to inhibit electrical breakdown of the composite dielectric material by (i) deflecting or scattering free electrons away from the particle cores and/or (ii) capturing free electrons by being transformed into relatively stable radical anions. Representative examples of the particle core material, linker, ICS group, and polymer molecule are titanium dioxide, a phosphonate group, a halogenated aromatic ring, and a polystyrene molecule, respectively.