Massachusetts Institute of Technology

Columbia University

Franco N C Wong

Jeffrey H Shapiro

Dirk Robert Englund

Franz Xaver Kaertner

Chee Wei Wong

Jung-Won Kim

Zheshen Zhang

Quntao Zhuang

A method for distributing a quantum digital key is described. The method comprises the use of an optical broadband source to generate an optical broadband signal. The optical broadband signal may be transmitted from a first party to a second party through an optical communication channel. The optical broadband signal may be transmitted with a low brightness, such as less than one photon/(sec-Hz), so as to be immune from passive attacks. Furthermore, a method for detecting the presence of active attackers is described. The method may comprise a coincidence measurement configured to measure the level of entanglement between an optical detection signal and an optical idler signal.

Methods for quantum key distribution and related devices

An interferometer module for quantum processing is described including a substrate having two or more input ports and two or more output ports; multiple photonic pathways embedded in the substrate for conveying photons from the two or more input ports and the two or more output ports; and one or more partial beam splitters embedded in the substrate in a photonic pathway for generating spatial and polarization entanglement.

Chip-scale interferometry for hyperentanglement processing

A compact, background-free, balanced cross-correlator enables (a) the detection of a timing error between two ultrashort pulses with (sub-)femtosecond resolution and (b) the timing synchronization of ultrashort pulse lasers using the output signal of the detector to close a phase-locked loop and can therefore serve as an integral part of femtosecond timing distribution and synchronization systems.

Compact background-free balanced cross-correlators

A control module is configured to receive one or more input signals. An optical selection network includes a plurality of optical input ports configured to receive respective optical waves at an operative wavelength, and at least one optical output port configured to provide an optical wave at the optical wavelength. The optical selection network is configured to receive one or more control signals from the control module, and in response to the control signals, provide a high transmission path for the operative wavelength from an optical input port, determined by the input signals, to the optical output port at a predetermined time with respect to a time reference in at least one of the input signals, and provide a low transmission path for the operative wavelength from each of a plurality of optical input ports, determined by the input signals, to the optical output port at the predetermined time.

Growing community of inventors

Lexington, MA, United States of America

Franco N C Wong