nanophotonics pick

Drilling holes of nanometric dimensions in a metal film is a way conceptually simple to realize new nanophotonic components. In spite of its visible simplicity, a hole drilled in an opaque screen still inspires new perspectives of applications.

In a review published in Nature, Cyriaque Genet and Thomas Ebbesen (Institut de Science and Ingenierie Supramoleculaires, Louis Pasteur university of Strasbourg) give a detailed overview of the current understanding and exploitation of the properties of these structures. The cases of the simple nano-openings, the nano-openings surrounded with concentric engravings, and with periodic networks of nanoholes are successively approached in a very didactic way. 

The field of application of these structures is very wide, and is approached through certain specific examples. In opto-electronics, they improve the extraction of light of electroluminescent diodes and allow the development of ultrafast miniaturized silicon detectors. Biochemistry is another major domain of applications, notably through the detection of individual fluorescent molecules and enhanced infrared vibrational spectroscopy.

I will attend to the next SPP meeting to be held in Dijon ( France ) next June.

In an oral contribution, I shall present our recent results towards the application of nanometric apertures in a gold film to biophotonics applications.

Link to SPP3 meeting : www.plasmonanodevices.org/spp3/

An amazing video found on Google :

http://video.google.fr/videoplay?docid=-4237751840526284618&q=physics&pr=goog-sl

Young’s double slit experiment explained in a classical and in a quantum world. It's worth having a look !

Note : it's seems the link doesn't work properly on every computer, just copy and paste the address in the directory.

I would like to support here a link to Marcel Leutenegger’s webpages on facilities towards optics learning and teaching. Very nice videos introducing the principles of image formation are available (to watch the videos, you’ll need a DivX decoder, see Marcel’s help webpage). 

By the way, I would also like to acknowledge Marcel’s nice work on microscopy at Theo Lasser’s group (EPFL, Lausanne).

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 :

"Creating hot nanoparticle pairs for surface enhanced Raman spectroscopy through optical manipulation"; Fredrik Svedberg, Zhipeng Li, Hongxing Xu, Mikael Käll, Nano Letters 6, 2639-2641 (2006).

Abstract : We use optical tweezers to move single silver nanoparticles into near-field contact with immobilized particles, forming isolated surfaceenhanced Raman spectroscopy (SERS) active Ag particle dimers. The surface-averaged SERS intensity increases by a factor 20 upon dimerization. Electrodynamics calculations indicate that the final approach between the particles is due to “optical binding”. The described methodology may facilitate controlled single molecule SERS analysis.

"Enhancing sensitivity of a whispering gallery mode biosensor by subwavelength confinement"; O. Gaathon, J. Cullic-Viskota, M. Mihnev, I. Terakoa, S. Arnold, Applied Physics Letters 89, 223901 (2006).

Abstract : the authors demonstrate enhanced sensitivity of a spherical whispering gallery mode biosensor WGMB by confining orbiting light near the surface using a subwavelength high refractive index layer on a fluorine doped silica microsphere. Their experiments at a free space wavelength of 1310 nm show that the frequency shift sensitivity by changing the external refractive index is increased by more than 700% by adding a 340 nm thick polystyrene layer. This advance is expected to move the WGMB well into the lead as the most sensitive method for unlabeled biosensing.

"Shining new light on neural circuits"; Greg Miller, Science 314, 1674-1676 (2006).

Abstract : Emerging methods that combine genetics and optics have neuroscientists glowing about the possibilities