Optical Properties of Nd-Doped Si-based thin films : towards an optical amplifier

This thesis focuses on the development and the study of Si-based materials dedicated to silicon photonics applications such as optical amplifier or laser. Si-rich SiO2 and Si-rich Si3N4 matrices containing Nd3+ rare earth ions were studied. In such matrices, Nd3+ ions benefit from energy transfer from defects states and/or Silicon nanoparticles present in the host resulting in an efficient indirect excitation of Nd3+ on a broad UV-VIS spectral range. Thus, remarkable emissions of Nd3+ ions at 920, 1064, and 1300 nm have been observed. In order to develop the waveguide active guiding layer from the two matrices and taking the Nd3+ ions emission as a figure of merit, the optimization of the Nd doped layers was carried out. The composition was engineered in terms of Si excess and Nd content by magnetron sputtering methods. Both matrices were annealed by classical or rapid thermal annealing processes in order to tune the layers' microstructures. Investigations of factors influencing the Nd3+ ions emission and sensitization mechanisms have been carried out in both matrices. In Si-rich SiO2, several kinds of Si-based sensitizers towards the Nd3+ ions have been evidenced. While in Si rich Si3N4 an excitation mechanism of Nd3+ ions dependent on silicon excess has been shown. Finally, waveguide based on Si-rich SiO2:Nd3+ layer has shown a significant net gain of 0.68 cm-1 (2.95dB.cm-1) at 1064 nm.