Résumé
This work is devoted to the preparation and study of optical limiting systems with carbon nanotubes suspensions. Various nanotubes samples, in the shape of powder or suspensions, were meticuly characterized by differents spectroscopics techniques. In particular, a complete Raman study was performed. A systematic<br />up-shift of RBM peaks was observed when setting in suspension. This upshift is assigned to a modification of nanotubes-surroundings interactions. The study of nanotubes suspensions optical limiting property is the man work of this thesis.<br />We studied the influence of nano-object structure onto optical limiting performances, thus demonstrating the importance of nano-object diameter. We also studied the nanotube electronic structure effect. We improved suspensions<br />performances with a new concept: combination of two nonlinear materials, nanotubes and two photon absorbers in the same cell. This system presents spectral and temporal broadband optical limiting efficiency, strongly enhanced in nanosecond regime, thus approaching performances levels required for operational application.