Abstract: A quantum key distribution system is deployed in an optical fiber network transporting classical data traffic. A source of entangled photon pairs is used to generate quantum keys. Classical data traffic is typically transported over channels in the C-band. If a pair of channels for transport of quantum data is available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in the C-band. If a pair of channels for transport of quantum data is not available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in a combined S-band and L-band. When a periodically-poled lithium niobate waveguide pumped with a laser is used for the source of entangled photon pairs, the output spectral properties are tuned by varying the temperature of the waveguide.

Abstract: Quantum networking systems and methods for routing entangled photons pairs are described herein. One quantum networking system includes entangled photon sources which generate entangled photons; optical output ports; a reconfigurable switching network connecting to the entangled photon sources and the output ports, which include a regular repeating structure of optical crossbar switches and interconnections for selectively routing individual ones of entangled photons pairs input to the network to and amongst the outputs; and a control module. The control module is configured to receive a request for entangled photons at the output ports; execute a routing algorithm to determine the state of the switches in the reconfigurable switching network to satisfy the request; and generate and transmit control signals to the switching network in order to set the states of the switches according to the executed routing algorithm. The reconfigurable switching network may be a Beneš or a banyan-type network architecture.

Abstract: A system for treating tissue includes a device including a first member and a second member arranged to move relative to the first member to treat tissue. The system also includes a processor configured to automatically control movement of the second member relative to the first member using position control methodology. A method of treating tissue includes providing a device having a first member and a second member arranged to move relative to the first member, moving the second member relative to the first member, and automatically controlling the movement of the second member using position control methodology.

Abstract: A quantum key distribution system is deployed in an optical fiber network transporting classical data traffic. A source of entangled photon pairs is used to generate quantum keys. Classical data traffic is typically transported over channels in the C-band. If a pair of channels for transport of quantum data is available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in the C-band. If a pair of channels for transport of quantum data is not available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in a combined S-band and L-band. When a periodically-poled lithium niobate waveguide pumped with a laser is used for the source of entangled photon pairs, the output spectral properties are tuned by varying the temperature of the waveguide.

Abstract: Operational parameters of a single-photon detector are determined with a continuous wave laser source. At a fixed trigger, a dark count probability and a series of count probabilities at different optical powers are determined. A particular optical power is selected by using a wide-range variable attenuator to attenuate the optical power of the continuous wave laser. The dark count probability and the count probabilities are determined for different trigger rates. The operational parameters include efficiency, afterpulsing constant, and detrap time. The operational parameters are computed by fitting the computed dark count probabilities and count probabilities to a user-defined relationship.

Abstract: Operational parameters of a single-photon detector are determined with a continuous wave laser source. At a fixed trigger, a dark count probability and a series of count probabilities at different optical powers are determined. A particular optical power is selected by using a wide-range variable attenuator to attenuate the optical power of the continuous wave laser. The dark count probability and the count probabilities are determined for different trigger rates. The operational parameters include efficiency, afterpulsing constant, and detrap time. The operational parameters are computed by fitting the computed dark count probabilities and count probabilities to a user-defined relationship.

Abstract: A method for determining a network configuration for the delivery of entangled photons individually to a plurality of users, the network comprising a plurality of inputs, switches, and outputs operatively connected by optical fibers; the plurality of switches being switchable between two states; the method comprising: determining the minimum number of switches necessary to deliver entangled photon pairs from a predetermined number of sources to a predetermined number of users, minimizing the loss experienced by an entangled photon passing through the switches by minimizing the number of switches that any one photon passes through by selecting only nondominated switch configurations; determining the minimum number of equivalent network switch configurations and eliminating all but one of the equivalent network switch configurations; and selecting an optimum network configuration by which the plurality of inputs and the plurality of outputs are operatively interconnected using a minimum number of switches in

Abstract: A hand-held ultrasound system includes integrated electronics within an ergonomic housing. The electronics includes control circuitry, beamforming and circuitry transducer drive circuitry. The electronics communicate with a host computer using an industry standard high speed serial bus. The ultrasonic imaging system is operable on a standard, commercially available, user computing device without specific hardware modifications, and is adapted to interface with an external application without modification to the ultrasonic imaging system to allow a user to gather ultrasonic data on a standard user computing device such as a PC, and employ the data so gathered via an independent external application without requiring a custom system, expensive hardware modifications, or system rebuilds.

Abstract: A hand-held ultrasound system includes integrated electronics within an ergonomic housing. The electronics includes control circuitry, beamforming and circuitry transducer drive circuitry. The electronics communicate with a host computer using an industry standard high speed serial bus. The ultrasonic imaging system is operable on a standard, commercially available, user computing device without specific hardware modifications, and is adapted to interface with an external application without modification to the ultrasonic imaging system to allow a user to gather ultrasonic data on a standard user computing device such as a PC, and employ the data so gathered via an independent external application without requiring a custom system, expensive hardware modifications, or system rebuilds.

Abstract: Operational parameters of a single-photon detector are determined with a continuous wave laser source. At a fixed trigger, a dark count probability and a series of count probabilities at different optical powers are determined. A particular optical power is selected by using a wide-range variable attenuator to attenuate the optical power of the continuous wave laser. The dark count probability and the count probabilities are determined for different trigger rates. The operational parameters include efficiency, afterpulsing constant, and detrap time. The operational parameters are computed by fitting the computed dark count probabilities and count probabilities to a user-defined relationship.

Abstract: A system for treating tissue includes a device including a first member and a second member arranged to move relative to the first member to treat tissue. The system also includes a processor configured to automatically control movement of the second member relative to the first member using position control methodology. A method of treating tissue includes providing a device having a first member and a second member arranged to move relative to the first member, moving the second member relative to the first member, and automatically controlling the movement of the second member using position control methodology.

Abstract: An ultrasound imaging system and method in which a transducer assembly in a probe housing in which sub-array beamforming and multiplexing operations are performed in the probe housing. The probe housing can be connected to a processor housing in which a second beamforming operation can be performed to generate images for display. The processor housing can be a handheld ultrasound display device for portable use.

Abstract: Operational parameters of a single-photon detector are determined with a continuous wave laser source. At a fixed trigger, a dark count probability and a series of count probabilities at different optical powers are determined. A particular optical power is selected by using a wide-range variable attenuator to attenuate the optical power of the continuous wave laser. The dark count probability and the count probabilities are determined for different trigger rates. The operational parameters include efficiency, afterpulsing constant, and detrap time. The operational parameters are computed by fitting the computed dark count probabilities and count probabilities to a user-defined relationship.

Abstract: A system for treating tissue includes a device including a first member and a second member arranged to move relative to the first member to treat tissue. The system also includes a processor configured to automatically control movement of the second member relative to the first member using position control methodology. A method of treating tissue includes providing a device having a first member and a second member arranged to move relative to the first member, moving the second member relative to the first member, and automatically controlling the movement of the second member using position control methodology.

Abstract: A fiber optic system includes a transmitter for transmitting high-speed streaming electrical data to a receiver for receiving the high-speed data. In order to transmit multiple channels in the system at high-speeds, an electrical data signal is converted into multiple optical sub-signals. Each of the multiple optical sub-signals are transmitted at the common wavelength on multi-spatial mode media. The receiver receives the multiple optical sub-signals as a multi-spatial mode optical signal and separates the multi-spatial mode optical signal into branch signals having a common wavelength. The receiver mixes each of the branch signals with optical carrier waves having the common wavelength and converts the branch signals into electrical signals. Digital signal processing is used to recover the data sub-signals which are used to recover the original data signal.

Abstract: A quantum key distribution system is deployed in an optical fiber network transporting classical data traffic. A source of entangled photon pairs is used to generate quantum keys. Classical data traffic is typically transported over channels in the C-band. If a pair of channels for transport of quantum data is available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in the C-band. If a pair of channels for transport of quantum data is not available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in a combined S-band and L-band. When a periodically-poled lithium niobate waveguide pumped with a laser is used for the source of entangled photon pairs, the output spectral properties are tuned by varying the temperature of the waveguide.

Abstract: The present invention relates to a lightweight, high resolution portable ultrasound system using components and methods to improve connectivity and ease of use. A preferred embodiment includes an integrated system in which the beamformer control circuitry can be inserted into the host computer as a peripheral or within the processor housing.

Abstract: A hand-held ultrasound system includes integrated electronics within an ergonomic housing. The electronics includes control circuitry, beamforming and circuitry transducer drive circuitry. The electronics communicate with a host computer using an industry standard high speed serial bus. The ultrasonic imaging system is operable on a standard, commercially available, user computing device without specific hardware modifications, and is adapted to interface with an external application without modification to the ultrasonic imaging system to allow a user to gather ultrasonic data on a standard user computing device such as a PC, and employ the data so gathered via an independent external application without requiring a custom system, expensive hardware modifications, or system rebuilds.

Abstract: A quantum key distribution system comprises a source of entangled photon pairs and two single-photon detectors. The source is coupled to each of the single-photon detectors by optical fiber. Operational systems parameters include the efficiency of the first single-photon detector, the efficiency of the second single-photon detector, and the maximum average number of photon pairs per unit time generated by the source. To characterize the operational systems parameters, the transmittances between the source and each single-photon detector are determined. The dark count probability of the first single-photon detector and the dark count probability of the second single-photon detector are determined. The count probability at the first single-photon detector, the count probability at the second single-photon detector, and the coincidence count probability are determined as a function of the optical power from the source.

Abstract: The present invention relates to an ultrasound imaging system in which the scan head either includes a beamformer circuit that performs far field subarray beamforming or includes a sparse array selecting circuit that actuates selected elements. When used with second stage beamforming system, three dimensional ultrasound images can be generated.