L'invention concerne un dispositif d'entree/sortie combine comprenant un mode d'affic... more L'invention concerne un dispositif d'entree/sortie combine comprenant un mode d'affichage dans lequel il fonctionne comme un affichage matriciel et un mode de detection dans lequel il recoit un signal d'entree optique. Ce dispositif comporte plusieurs circuits d'elements d'image disposes sous forme d'affichage matriciel et plusieurs capteurs optiques disposes sous forme de matrice de detection. Les capteurs optiques et les circuits de pixels sont integres sur le meme circuit et les lignes de commande utilisees pour commander les circuits de pixels sont avantageusement reutilisees pour commander les capteurs optiques. Une pluralite de capteurs optiques peuvent etre actives en meme temps, ce qui permet une discrimination des signaux d'entree par le geste.
Two-photon absorption spectra of Al0.4Ga0.6As/GaAs quantum wells in static electric fields are in... more Two-photon absorption spectra of Al0.4Ga0.6As/GaAs quantum wells in static electric fields are investigated experimentally. A drastic field-induced increase in the absorption peaks at energies close to half the bandgap energy is reported for the first time. In particular, we observed the rise and red-shift of a peak corresponding to halfthe lowest light-hole exciton energy not seen in non-biased quantum wells. For moderate fields, the results agree with a theory based on a zero-bias infinite- level model, whereas the large peak value at stronger fields is explained by a two-level model. Contrary to bulk GaAs, a large value of the third order optical susceptibility is predicted just below the two-photon absorption edge at which the biased quantum wells are highly transparent. This gives a large figure of merit for ultrafast optical nonlinearities. We have also theoretically and experimentally investigated time-resolved two-photon absorption in bulk GaAs and Ga-doped CdTe with picosec...
L'invention concerne un dispositif d'entree/sortie combine comprenant un mode d'affic... more L'invention concerne un dispositif d'entree/sortie combine comprenant un mode d'affichage dans lequel il fonctionne comme un affichage matriciel et un mode de detection dans lequel il recoit un signal d'entree optique. Ce dispositif comporte plusieurs circuits d'elements d'image disposes sous forme d'affichage matriciel et plusieurs capteurs optiques disposes sous forme de matrice de detection. Les capteurs optiques et les circuits de pixels sont integres sur le meme circuit et les lignes de commande utilisees pour commander les circuits de pixels sont avantageusement reutilisees pour commander les capteurs optiques. Une pluralite de capteurs optiques peuvent etre actives en meme temps, ce qui permet une discrimination des signaux d'entree par le geste.
Two-photon absorption spectra of Al0.4Ga0.6As/GaAs quantum wells in static electric fields are in... more Two-photon absorption spectra of Al0.4Ga0.6As/GaAs quantum wells in static electric fields are investigated experimentally. A drastic field-induced increase in the absorption peaks at energies close to half the bandgap energy is reported for the first time. In particular, we observed the rise and red-shift of a peak corresponding to halfthe lowest light-hole exciton energy not seen in non-biased quantum wells. For moderate fields, the results agree with a theory based on a zero-bias infinite- level model, whereas the large peak value at stronger fields is explained by a two-level model. Contrary to bulk GaAs, a large value of the third order optical susceptibility is predicted just below the two-photon absorption edge at which the biased quantum wells are highly transparent. This gives a large figure of merit for ultrafast optical nonlinearities. We have also theoretically and experimentally investigated time-resolved two-photon absorption in bulk GaAs and Ga-doped CdTe with picosec...
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Papers by Johan Bergquist