Quantum Optics
Photon-Pair Generation in Optical Fibers
- Photon pair generation
- Non linearity of optical fibers is used to produce photon pairs
Optical fibers are made of silica, a material that is transparent at telecom wavelength. Silica is also slightly dispersive, nonlinear and, in some cases, birefringent. Combining these properties, one can design efficient fiber-optics photon pair sources for quantum optics and quantum information processing at telecom wavelength. Generation of photon-pairs that are entangled in several degrees of freedom (energy, time, polarization) is of special interest.
Collaboration : David Amans, Univ. Lyon 1 ; Anh Tuan Ngyuen ; Kien Phan Hyu, Univ. de Franche-Comté ; Serge Massar ; Stephane Clemen
Spontaneous Raman Scattering in Optical Fibers
- Spontaneous Raman spectrum
- Raman scattering in optical fibers is a noise for photon pair production.
Raman scattering refers to an inelastic scattering phenomenon observed in many material that converts photons from higher to lower energy. Stimulated Raman scattering in optical fibers has many applications in photonics : it is used amplifiers, wavelength converters, and lasers. In contrast, spontaneous Raman scattering is usually considered as a noise in both classical and quantum photonics, particularly for photon-pair generation in fibers (see above). Ways to suppress spontaneous Raman scattering are currently investigated.
Collaboration : David Amans, Univ. Lyon 1 ; Stephane Clemen ; Serge Massar
Colloidal Nanocrystals as Single-Photon emitters
- Addressing multiple nanocrystals
- We can switch quantum dots on/off on demand (Dec. 2009)
CdSe/ZnS colloidal nanocrystals have been recently recognized as good single-photon emitters in the visible spectrum. The wavelength of these emitters can be shifted by tunning their size and shape, or by changing their composition. We are currently building an apparatus that will allow us to study single-photon emission of nanocrystals and develop a scalable single-photon multi-wavelength source.
Collaboration : Karel Lambert, UGent ; Zeger Hens, UGent (as a part of the IAP Photonics@be [IAP 6-10])
Atomic Physics
Dipole Trapping and Manipulation of Cold Atoms
- Reconfigurable optical tweezers for single atoms
- We designed an optical system that generates many dipoles traps for single 87Rb atoms. (Apr. 2008)
Optical tweezers are a well established techique (especially in biology) for manipulation micron-sized particles. It makes use of a particular form a light/matter interaction called the dipole force. Our goal is to apply the same technique to atoms. We want to use optical tweezers to trap single 87Rb atoms and demonstrate that one can move atoms around without loosing them. Long term goal is to demonstrate a quantum information network based on single atoms coupled to high-Q micro-cavities. The experiment is build in Oxford in A. Kuhn’s group.
Collaboration : Axel Kuhn, Oxford
Optimal Control of Atomic Transport
Dipole force is a unique phenomenon that allows to manipulate cold atomic clouds as well as single atoms using light. Light produces an effective potential in which atoms can be trapped and even transported. Transport can be achieved by dynamically shaping the light beam that traps atoms. For been efficient in the context of quantum information processing, transport must be fast and efficient : target position must be reached with minimal kinetic energy and minimal time. We apply techniques of Optimal Control Theory to analyze ways of transporting atoms trapped in an optical beam that is spatially modulated by a digital light modulator, a technique applied in the experiments taking place in A. Kuhn’s group in Oxford.
Collaboration : Axel Kuhn, Oxford
PUBLICATIONS
Revues (3 dernières)
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Conférences (3 dernières)
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