Yassine Benachour

... MSSkolnick, S.Brand, TFKrauss, OZKarimov, RMStevenson, DMWhittaker, I.Culshaw, RMde la Rue, “Experimental technique to determine the band structure of two-dimensional photonic lattices,”IEE Proc.-Optoelectron.145,398-402 (1998) [9] D.Coquillat, J.Torres, D.Peyrade, R ...

We report experimental results for the band structure of 2-dimensional triangular photonic crystals etched in SOI wafers. Boundary conditions at the surface and at the border of the etched area of the slab, allow the excitation of guided modes via diffraction phenomena using surface coupling techniques and the determination of the structure band diagram above and below the light cone. These non-destructive techniques, usable for non-active materials, allow fast characterization of technical processes and the location in reciprocal space of areas with unique dispersion properties.

In continuation of our studies on donor-acceptor substituted heteroaromatic nonlinear optical chromophores, we have developed a new series of thiophene derivatives containing dialkylamino electron-donor and tricyanovinyl electron-acceptor substituents. EFISH measurements indicate that the combination of tricyanovinyl acceptors and thiophene conjugating moieties yields dramatically enhanced molecular nonlinear properties [(beta) (mu) (at (lambda) equals 1.907 micrometers ) equals 6000 - 9100 X 10-48 esu].

... MSSkolnick, S.Brand, TFKrauss, OZKarimov, RMStevenson, DMWhittaker, I.Culshaw, RMde la Rue, “Experimental technique to determine the band structure of two-dimensional photonic lattices,”IEE Proc.-Optoelectron.145,398-402 (1998) [9] D.Coquillat, J.Torres, D.Peyrade, R ...

The “marriage” between photonic crystal structures and nonlinear optics is studied in the present paper. We demonstrate the considerable interest in the enhancement of nonlinear effects using photonic crystals (PCs). The Nano structuring of materials allows realizing the phase matching in photonic crystals. Phase tuning is achieved using the anomalous dispersion existing at the edges of photonic forbidden bands. This type of structure also makes it possible to obtain high densities of modes of the optical field at the frequency of the excitation wave, where it is desired to obtain significant nonlinear effects. An introduction and discussion of some of the basic principles of nonlinear and photonic crystals are given. The focus is on engineered of these PCs by using some total nonlinear materials or a mix with silica. With this “marriage”, it is then possible to realize, on a microscopic scale, different passive optical functions (filters, switches, tunable) or active functions (amp...

Ce travail de these constitue une contribution theorique et experimentale aux etudes sur les cristaux photoniques et leur utilisation en optique non lineaire. Dans ce travail, nous avons etudie les proprietes de dispersion de ces cristaux afin de les utiliser dans des structures en materiaux presentant de grandes non linearites optiques. Des modelisations ont ete effectues dans des structures a 1D d'epaisseur finie pour etudier facilement l'influence des divers parametres et ont permis de dimensionner une structure guidante gravee dans une couche de GaN deposee sur saphir pour l'exaltation de la generation de la seconde harmonique : une ebauche de realisation est presentee. Des techniques non destructives de couplage par la surface- ellipsometrie spectroscopique et spectrometrie infrarouge a transformee de Fourier (s-FTIR)- ont ete utilisees pour caracteriser des cristaux photoniques 2D realises dans des substrats de SOI. Aux grandes longueurs d'ondes, elles nous ont...