Raman amplification in nanoparticles doped glasses

Resonant Raman effects are studied for CdSxSe1−x nanoparticles in a silicate glass matrix in order to explore new possibilities of Raman amplification for telecommunication fibers. Nanoparticles with diameters ranging from less than 2 nm up to 6 nm are excited with the 458 nm, 488 nm and 633 nm laser lines corresponding both to resonance and off-resonance conditions. Due to confinement effects the resonance conditions are achieved at a given frequency by varying the size of the nanoparticles. In resonance no enhancement is observed for the silicate glass matrix but the (1LO-CdS), (2LO-CdS), (1LO CdSe + 1 LO CdS) modes are strongly enhanced showing the possibility of resonant Raman amplification of the discrete frequencies of the LO modes and of their overtones.