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 source of photon pairs. 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 adjusting the optical power of the source of photon pairs. 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: Systems and methods are described that derive a relationship between an optical transmitter's extinction ratio (Er) and its interferogram wing-to-peak ratio (Iwp). The change in an optical transmitter's Iwp correlates with a change in measured Er. As the Er of a telecom signal changes, the power of the modulated signal's interferogram wings change. After a relationship between Iwp and measured Er has been derived for an optical transmitter, the relationship may be used after deployment to determine an Er by measuring an Iwp.

Abstract: Systems and methods are described that measure the OSNR of an optical channel. Embodiments provide OSNR measurement methods that distinguish the intensities of the coherent modulated signal from the incoherent noise intensity occupying the same optical band using a calibration factor ?.

Abstract: Systems and methods are described that measure the OSNR of an optical channel. Embodiments provide OSNR measurement methods that distinguish the intensities of the coherent modulated signal from the incoherent noise intensity occupying the same optical band using a calibration factor ?.

Abstract: There is provided a drying system for an image forming machine which has a plenum and nozzle to supply drying air to impinge upon a moving substrate, where the air impinges upon the substrate in substantially the same direction in which the substrate is moving, and where the air impinges upon the substrate immediately after a colorant has been deposited upon the substrate and before it touches another object.

Abstract: There is provided a feeding system for an image forming machine using a first feeder roll and a press roll that form a nip between them though which a substrate is passed, and a second feeder roll located after a printing zone, where the first and second feeder roll surfaces move at the same speed.

Abstract: There is provided a feeding system for an image forming machine using a first feeder roll and a press roll that form a nip between them though which a substrate is passed, and a second feeder roll located after a printing zone, where the first and second feeder rolls move at the same speed.