nanophotonics pick - Jerome Wenger NanoBioPhotonics

NanoLum workshop presentations

3 Avril 2008 , Rédigé par JW Publié dans #Nanophotonics pick

Full text presentations of the NanoLum workshop (luminescence of nano-objects) are freely available on the net : http://nanolum.univ-lyon1.fr/spip.php?article95 . For an introduction to topics related to nanophotonics, it’s nice to have a look at this website :

- near-field optics

- single molecule fluorescence

- advanced optical microscopy

- plasmonics

- nanoparticle detection

Review Surface-Enhanced Fluorescence

14 Mars 2008 , Rédigé par JW Publié dans #Nanophotonics pick

Emmanuel Fort and Samuel Grésillon recently published a very nice and complete review on surface-enhanced fluorescence. Highly recommended !

Fluorescence is widely used in optical devices, microscopy imaging, biology, medical research and diagnosis. Improving fluorescence sensitivity, all the way to the limit of single-molecular detection needed in many applications, remains a great challenge. The technique of surface enhanced fluorescence (SEF) is based upon the design of surfaces in the vicinity of the emitter. SEF yields an overall improvement in the fluorescence detection efficiency through modification and control of the local electromagnetic environment of the emitter. Near-field coupling between the emitter and surface modes plays a crucial role in SEF. In particular, plasmonic surfaces with localized and propagating surface plasmons are efficient SEF substrates. Recent progress in tailoring surfaces at the nanometre scale extends greatly the realm of SEF applications. This review focuses on the recent advances in the different mechanisms involved in SEF, in each case highlighting the most relevant applications.

http://www.iop.org/EJ/abstract/0022-3727/41/1/013001/

First book on diffraction

7 Janvier 2008 , Rédigé par JW Publié dans #Nanophotonics pick

World’s first published studies on optical diffraction dating back to 1664, where the word “diffraction” itself was introduced for the first time. The original text is downloadable for free at the French National Library website http://gallica.bnf.fr/

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Winter 2007 article selection

26 Décembre 2007 , Rédigé par JW Publié dans #Nanophotonics pick

As member of the OMNT “materials and components for optics” committee, I regularly give a selection and a brief description of articles, that I found particularly relevant to the field. Here is my latest selection :

" Nano-optics from sensing to waveguiding"; Surbhi Lal, Stephan Link et Naomi J. Halas, Nature Photonics 1, 641-648 (2007).

The design and realization of metallic nanostructures with tunable plasmon resonances has been greatly advanced by combining a wealth of nanofabrication techniques with advances in computational electromagnetic design. Plasmonics — a rapidly emerging subdiscipline of nanophotonics — is aimed at exploiting both localized and propagating surface plasmons for technologically important applications, specifically in sensing and waveguiding. Here we present a brief overview of this rapidly growing research field.

"Label-free optical imaging of mitochondria in live cells"; David Lasne, Gerhard. A. Blab, Francesca De Giorgi, François Ichas, Brahim Lounis et Laurent Cognet, Optics Express 15, 14184-14193 (2007).

The far-field optical imaging of mitochondria of live cells without the use of any label is demonstrated. It uses a highly sensitive photothermal method and has a resolution comparable to confocal fluorescence setups. The morphological states of mitochondria were followed under different physiological treatments, and the role of cytochrome c was ruled out as the main origin of the photothermal signas. This label free optical method provides a high contrast imaging of live mitochondria and should find many applications in biosciences.

"Generation of single optical plasmons in metallic nanowires coupled to quantum dots"; A. V. Akimov, A. Mukherjee, C. L. Yu, D. E. Chang, A. S. Zibrov, P. R. Hemmer, H. Park & M. D. Lukin, Nature 450, 402-406 (2007).

Control over the interaction between single photons and individual optical emitters is an outstanding problem in quantum science and engineering. It is of interest for ultimate control over light quanta1, as well as for potential applications such as efficient photon collection2, single-photon switching3 and transistors4, and long-range optical coupling of quantum bits5,6. Recently, substantial advances have been made towards these goals, based on modifying photon fields around an emitter using high-finesse optical cavities2,3,5–8. Here we demonstrate a cavity-free, broadband approach for engineering photon–emitter interactions4,9 via subwavelength confinement of optical fields near metallic nanostructures10– 13. When a single CdSe quantum dot is optically excited in close proximity to a silver nanowire, emission from the quantum dot couples directly to guided surface plasmons in the nanowire, causing the wire’s ends to light up. Non-classical photon correlations between the emission from the quantum dot and the ends of the nanowire demonstrate that the latter stems from the generation of single, quantized plasmons. Results from a large number of devices show that efficient coupling is accompanied by more than 2.5-fold enhancement of the quantum dot spontaneous emission, in good agreement with theoretical predictions.

Next meeting : BCP Marseille Dec 03rd

22 Novembre 2007 , Rédigé par JW Publié dans #Nanophotonics pick

Scientific meeting of Marseille’s community of biologists, chemists and physicists. The webpage is somehow difficult to find so here a direct link :

http://www.fresnel.fr/mosaic/BCP/journee.html