Thales

Thomson-csf

Universitaet Leipzig

Le Centre National De La Recherche

Universitat Leipzig

Thierry Debuisschert

Michel Papuchon

Jean-Paul Pocholle

Erich Spitz

Ludovic Mayer

Dominique Delacourt

Jan Meijer

Christian Larat

Eric Lallier

Loic Morvan

Rosa Tualle-Brouri

Ovidiu Brinza

Jocelyn Achard

Alexandre Tallaire

Jerome Lodewyck

Sébastien Pezzagna

Loic Toraille

Mayeul Chipaux

Loïc Toraille

A method for manufacturing a device including a diamond crystal, the method including making available a substrate, growing a crystalline diamond layer on the substrate, the layer having a crystal lattice, the layer including at least a first set of XV centers in the crystal lattice, each XV center having a quantification axis, a main direction being defined for the first set, the quantification axes of the XV centers of the first set being parallel to the main direction, the normal direction being distinct from the main direction of the first set, removing a first part of the diamond layer in order to reveal a first face perpendicular to the main direction of the first set, and removing of a second part of the diamond layer in order to reveal a second face perpendicular to the first face.

Method for manufacturing a device comprising a diamond crystal

The invention relates to a device for the frequency analysis of a signal, comprising a diamond crystal having NV centers defining sub-regions, an excitation unit for optically or electrically exciting each sub-region, an injection unit for injecting a signal so that the sub-region is in the presence of the signal, a magnetic field generator designed so as to generate a magnetic field on each sub-region, the magnetic field having a spatial variation of amplitude in a first direction, and a detector for detecting the resonance frequency of each sub-region of the region, the detector comprising an electrical contact for detecting the charges created in a sub-region, and a reading circuit.

Device and method for frequency analysis of a signal

A system for analyzing a microwave-frequency signal by imaging is provided, comprising:

System for analysis of a microwave frequency signal by imaging

A continuous variable quantum encryption key distribution system comprises a sender (Alice) able to randomly choose the phase and the amplitude of each coherent light pulse of a signal, to provide a coherent state defined by a first quadrature and a second quadrature that are random, and to transmit to a receiver (Bob) the signal pulses (S) and a local oscillator (LO), the receiver comprising a homodyne detector () for measuring a randomly chosen quadrature of a signal pulse. The sender comprises a device for time-division multiplexing the pulses of the signal (S) and of the local oscillator (LO) to handle the transmission over an optical fiber () of the signal and local oscillator pulses to the receiver. The receiver comprises a demultiplexer (), able to send the received pulses over a first channel (), or over a second channel (). The channels are applied as inputs to the homodyne detector (). One of the first and second channels includes a phase modulator (), enabling a random selection by the homodyne detector of a quadrature from the first and the second quadratures of a coherent state of a signal pulse. A delay line (), is used for resynchronizing the signal and local oscillator pulses.

Continuous variable quantum encryption key distribution system

Encoding digital data intended for transmission by a particle flow of single particles, includes: encoding digital data on a parameter x of said particle flow, wherein the parameter x has a conjugated parameter y of said particle flow; and ensuring that said parameter x and said conjugated parameter y are in a minimum state (&#x394;x. &#x394;y=1).

Quantum cryptography transmission method and system

Quantum cryptography by polarization ambiguity is generally used but it involves polarization-maintained fibers. This invention proposes an alternative: quantum cryptography by ambiguity in time. It comprises the conversion of K bits to be transmitted into a train of K pulses of particle flows of time width &#x394;T and whose frequency Tb, is predetermined knowing that each of the K pulses being shifted or not in time such that the kpulse is shifted by a duration trespectively t, with respect to the initial instant of the period depending on the value '0', respectively '1' of the kbit, where k is an integer such that 0&#x2266;k&#x3c;K and the shifts tand tare such that 0&#x2266;t,t&#x2266;Tb&#x2212;&#x394;T and 0&#x3c;|t&#x2212;t|&#x3c;&#x394;T.

An unstable optical cavity for laser beams, having at least 3 deflection means for making a beam created in the cavity undergo at least three changes in direction so to form an optical ring path, and an optical magnification set disposed among the deflecting means. The at least 3 deflection means are prisms, each of which has an air-glass reflecting interface that provides one of the changes in direction by total reflection. A first of the at least 3 prims is positioned at an output of the cavity and has an air-glass reflecting interface with an insufficient size for a total reflection of the beam in the cavity, and remaining ones of the prisms have an air-glass reflecting interface with a sufficient size for a total reflection of the beam in the cavity.

Unstable optical cavity for laser beam

Disclosed is a compact optical source capable of emitting wavelengths (notably in the blue spectrum) which it is difficult for standard laser diodes to achieve. This source has a laser (or laser diode) emitting at a wavelength .lambda.oi, a non-linear medium (NLM) in which the phase matching condition is achieved at a wavelength .lambda.o.sub.a belonging to the set of .lambda.o.sub.i values, a mirror M.sub.l transparent at .lambda.o.sub.i /2 and reflective at .lambda.oi placed at output of the medium (NLM) By reinjecting wavelengths .lambda.oi.noteq..lambda.oa into the laser, it is possible to lock the emission of the laser to .lambda.oa and thus set up a high-powered optical source .lambda.o.sub.a /2. Application: blue sources.

Compact optical source based on the frequency doubling of a laser and

Disclosed is a non-linear optical device in which the non-linear medium comprises a circular surface on which the light beam to be processed gets reflected. A structure such as this can be used to resolve the difficulties of making mirrors of the cavity containing the non-linear medium.

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Orsay, France

Thierry Debuisschert