Abstract: A novel methodology for characterizing and calibrating an entangled photon distribution system is disclosed. The entangled photon distribution system includes at least a source of entangled photon pairs, two photon detectors which detect photons among two channels and a controller. The methodology includes: for at least two different operational setting levels of the source of entangled photon pairs, measuring count rates for photons detected by the two photon detectors, individually and coincidently; fitting the measured individual and coincidence count rate data for the at least two different operational setting levels with theoretical models of detection probability; and determining operational parameters of the system from the fitting.

Abstract: Methods and apparatuses are provided that compensate for the polarization dependent loss (PDL) of fiber-optic quantum channels. Compensation is accomplished by inserting a compensating PDL into another quantum channel carrying entangled photons that are entangled with photons in the first channel having losses that are to be compensated for. By selecting the optimum magnitude and orientation for the compensating PDL, compensation for the PDL in the first channel is maximized.

Abstract: Methods and apparatuses are provided that compensate for the polarization dependent loss (PDL) of fiber-optic quantum channels. Compensation is accomplished by inserting a compensating PDL into another quantum channel carrying entangled photons that are entangled with photons in the first channel having losses that are to be compensated for. By selecting the optimum magnitude and orientation for the compensating PDL, compensation for the PDL in the first channel is maximized.

Abstract: Methods and systems for measuring interferometric visibility of telescopic signals using resources having imperfect quantum entanglement are disclosed. The novel methodology employed by embodiments of the present invention takes into account the difficulty in creating entanglement between distance telescopes, and describes how to incorporate problems associated with distributing quantum entanglement into the measurement procedure. This allows the distance that two telescopes in an optical array are spaced apart to be increased while still interacting.

Abstract: A novel methodology for characterizing and calibrating an entangled photon distribution system is disclosed. The entangled photon distribution system includes at least a source of entangled photon pairs, two photon detectors which detect photons among two channels and a controller. The methodology includes: for at least two different operational setting levels of the source of entangled photon pairs, measuring count rates for photons detected by the two photon detectors, individually and coincidently; fitting the measured individual and coincidence count rate data for the at least two different operational setting levels with theoretical models of detection probability; and determining operational parameters of the system from the fitting.

Abstract: Methods and systems for measuring interferometric visibility of telescopic signals using resources having imperfect quantum entanglement are disclosed. The novel methodology employed by embodiments of the present invention takes into account the difficulty in creating entanglement between distance telescopes, and describes how to incorporate problems associated with distributing quantum entanglement into the measurement procedure. This allows the distance that two telescopes in an optical array are spaced apart to be increased while still interacting.

Abstract: A dual mode electronic intrusion or burglar alarm system for use with a door or window which can be opened and closed comprises a switch actuatable by the door or window, a control circuit, including time delay circuitry, operatively connected to the switch and responsive to switch actuation to operate in either of two modes, and an alarm connected to be operated by the control circuit. When the system is in operation and armed in a first mode, initial actuation of the switch in response to opening of the door or window causes the control circuit to actuate the alarm for a first predetermined interval of time, then to shut off the alarm and arm itself in a second mode wherein subsequent actuation of the switch in response to closing of the door or window causes the control circuit to again actuate the alarm for a second predetermined interval of time. The system can be reset for operation in the first mode either during the first interval of time, or at any time thereafter, i.e.