摘要:
Methods and apparatus for generating coherent optical pulses (P1′, P2′) in a quantum key distribution (QKD) station (Alice-N) of a QKD system (10) without using an optical fiber interferometer (12) are disclosed. The method includes generating a continuous wave (CW) beam of coherent radiation (R) having a coherence length LC and modulating the CW beam within the coherence length. The invention obviates the need for an interferometer loop to form multiple optical pulses from a single optical pulse, thereby obviating the need for thermal stabilization of the interferometer loop at the QKD station Alice-N.
摘要:
The present invention is directed to an integrated system for performing dispersion compensation on wavelength channels in WDM or DWDM transmissions. The system includes a tunable integrated dispersion compensation module that performs chromatic dispersion compensation and polarization mode dispersion compensation on each of the wavelength channels in the transmission. Feedback is used to adjust the tunable integrated dispersion compensation module until receiver performance is optimized.
摘要:
A one-way stabilized QKD system (10) that utilizes a control signal (CS) and a quantum signal (QS) that travel the same path through the system from a first QKD station (Alice) to a second QKD station (Bob). The control signal is detected at Bob and used to stabilize Bob's side of the interferometer against phase variations. The system also includes a polarization control stage (200) that controls (e.g., scrambles) the polarization of the photons entering Bob. The combination of the polarization control and the active phase stabilization of the interferometer at Bob's end allows for the stable operation of the interferometer when used as part of a one-way QKD system.
摘要:
A one-way stabilized QKD system (10) that utilizes a control signal (CS) and a quantum signal (QS) that travel the same path through the system from a first QKD station (Alice) to a second QKD station (Bob). The control signal is detected at Bob and used to stabilize Bob's side of the interferometer against phase variations. The system also includes a polarization control stage (200) that controls (e.g., scrambles) the polarization of the photons entering Bob. The combination of the polarization control and the active phase stabilization of the interferometer at Bob's end allows for the stable operation of the interferometer when used as part of a one-way QKD system.
摘要:
The present invention is directed to liquid crystal diffraction gratings with electrically controlled periodicity. An electrical field is applied to liquid crystal device wherein the liquid crystals align to form a diffraction grating. The period of the diffraction grating is varied by changing the applied electrical field. The diffraction grating therefore has a period that can be varied by an electrical field.