PhD defense Hugo Bruhier

"Development of a plasmonic sensor for air quality control"

Abstract:

The objective of this thesis is the development of a brand-new type of differential plasmonic sensor based on the optical switch effect. This sensor is applied to the detection of two atmospheric pollutants, nitrogen dioxide NO2 and ozone O3, causing public health problems. The effect of the plasmonic switch, created with a deep metallic diffraction grating, consists in an energy transfer between the diffracted orders -1 and 0 and allows a differential measurement of their efficiencies, in particular overcoming intensity variations of the light source. The joint use of functional materials thin films (copper phthalocyanine and indigo) aims to improve the sensor selectivity with respect to these two gases (NO2 and O3). The plasmonic switch effect is analyzed according to the different parameters of the grating using its angular response and the digital processing of the signals is explored. A unique diffractive structure coated by one or the other of the two functional layers (Copper Phthalocyanine or Indigo) has been optimized for the detection of NO2 and O3 pollutants. This effect shown a first result of detection limite of 10^-7 RIU and suitable sensitivity to nitrogen dioxide (detection liumit of 20 ppm) and to ammonia (detection limit of 1 ppm).

Jury:

• Isabelle Verrier, Laboratoire Hubert Curien, Supervisor

• Jérôme Brunet, Laboratoire IP, Université Clermont-Ferrand, Co-Supervisor

• Yves Jourlin, Laboratoire Hubert Curien, Co-Supervisor

• Pierre Bérini, Laboratoire CRPuO, Université Ottawa, Examiner

• Christelle Varenne, Laboratoire IP, Université Clermont-Ferrand, Examiner

• Jean-Paul Viricelle, Laboratoire Georges Friedel, Ecole des mines Saint Etienne, Examiner

• Olivier Gauthier-Lafaye, Laboratoire LAAS Toulouse, Reviewer

• Thierry Grosjean, Laboratoire FEMTO Besançon, Reviewer

• Olivier Parriaux, Laboratoire Hubert Curien, Invited

• Valentin Gaté, Société SILSEF, Invited