Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Quantum Optics Jena Gmbh

Oliver De Vries

Marco Plotner

Alessandro Zannotti

Jens Limpert

Thomas Schreiber

Adrià Sansa Perna

Adriá Sansa Perna

René Heilmann

Marco PLÖTNER

A method for polarization alignment, preferably for and/or in the case of optical communication, quantum cryptography and/or quantum computing, comprising a source () for generating polarization-entangled photon pairs and two detection modules (), wherein the source () for transmitting the photons is connected via in each case one quantum channel () to the two detection modules, and wherein each detection module measures the polarization of the photons in two non-orthogonal bases, and including a polarization compensation unit () for polarization alignment of the polarization change during the transmission of the photons via the quantum channels, wherein the polarization compensation unit () has several optical components. The polarization alignment is effected by a downhill simplex algorithm and/or by a deterministic algorithm.

Method for polarization alignment

A method for quantum communication between at least three receivers includes: The photons generated in step i) are generated in a signal wavelength range and an idler wavelength range that are spectrally separated from one another, and, in step ii), the photons are assigned to the quantum channels () such that, in step iii), only signal photons are transmitted to a first receiver () for the communication with all other receivers (), and, in step iii), only idler photons are transmitted to a second receiver () for the communication with all other receivers (), and, in step iii), both signal photons and idler photons are transmitted to the further receivers () for the communication with all other receivers (), and all receivers () are connected to the source () via in each case one quantum channel ().

Method for quantum communication

The invention relates to a method for producing an optical fiber coupler, having the following method steps:

Production of a fiber coupler

A method for generating a laser pulse train is provided, including at least the following method steps: generating a laser pulse train at a pulse repetition frequency; coupling the laser pulse train into an acousto-optical modulator, and selecting individual laser pulses of the laser pulse train. A system for generating a laser pulse train is also provided, including at least a pulsed laser and an acousto-optical modulator, and an associated control device.

Growing community of inventors

Jena, Germany

Oliver De Vries