PHOTONIC INTEGRATED CIRCUIT DESIGN FOR PLUG-AND-PLAY MEASUREMENT DEVICE INDEPENDENT-QUANTUM KEY DISTRIBUTION (MDI-QKD)

• Main Authors: Bush, Stephen Francis, Challener, William Albert
• Format: Patent
• Language: English
• Published: 07.12.2023
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

A photonic integrated circuit includes a waveguide that receive photons from an optical fiber and directs the photons in a loop formed by the waveguide. The circuit also includes one or more of a variable optical attenuator and configured to adjust a number of the photons between a key level and one or more decoy levels, an intensity modulator coupled with the waveguide and configured to adjust a number of the photons between a key level and a decoy level, and a phase shifter coupled with the waveguide and configured to change a phase of the photons. The waveguide is configured to direct one or more of the photons back out of the optical fiber after the one or more of the photons has passed through the loop formed by the waveguide with a polarization state of the one or more of the photons rotated by 90°.