PDFCreator, Job 2
Transcription
PDFCreator, Job 2
LABORATOIRE DE PHOTONIQUE ET DE NANOSTRUCTURES Séminaire régulier Mercredi 11 Janvier 2006 à 11h Salle des séminaires Richard Planel, bâtiment D1 A real-space, real-time investigation of slow light in photonics crystals and guided surface plasmons L. (Kobus) Kuipers NanoOptics Group , Center for Nanophotonics , FOM Institute for Atomic and Molecular Physics (AMOLF) Amsterdam , The Netherlands Manipulating light at a subwavelength lengthscale is the main aim of the rapidly growing research field of Nanophotonics. Photonic and plasmonic crystal structures are powerful concepts for gaining optical control. An exciting topic nanophotonic light manipulation will be presented: slow light. Local time-resolved measurements of slow light and slow guided surface plasmons will be presented. Phase-sensitive and time-resolved near-field optical measurements of ultrafast pulse propagation [1] through line defects in photonic crystals yield information unobtainable by conventional “black box”-measurements. Not only do we unambiguously obtain the group velocities of the pulses, but we also detect all the different spatial frequencies of the light inside the structure. By measuring the excited spatial frequencies (wavevectors) for different light frequencies (energy), we are able to reconstruct the photonic band diagram of the structure. We are able to map several Brillouin zones. [2] In the measured band diagrams we identified the crossing of a very flat band with a waveguide mode band. Local time-resolved measurements at the correct frequency revealed that the crossing leads to a localised and stationary light field. An upper bound for its velocity would be c/1000 [3]. Recently, we have been able to observe a significant slow down of guided surface plasmon polaritons [4]. [1] M.L.M. Balistreri, H. Gersen, et al., Science 294 (5544), 1080 (2001). [2] H. Gersen, et al., Phys. Rev. Lett. 94, 123901 (2005). [3] H. Gersen, et al., Phys. Rev. Lett. 94, 073903 (2005). [4] M. Sandtke, et al., unpublished Contact: Anne Talneau Tel : 01-6963-6146 Email: [email protected] Pour se rendre au LPN : http://www.lpn.cnrs.fr/fr/Acces.php LPN – CNRS, route de Nozay – 91460 MARCOUSSIS http://www.lpn.cnrs.fr