Assessment of the Excited Carrier absorption losses in Si-nc rib-waveguides

Abstract A detailed study of the free carrier absorption trying to quantify the effects in terms of additional losses. losses at 1.5 tm has been performed on silicon-nanocrystal rib waveguides by pumping at 532 nm. At the highest photon flux, II. EXPERIMENTAL the measured losses were about 6 dB/cm. We demonstrate that The studied samples are Si-rich silicon oxide and SiO2 the dynamics of the carrier absorption is that of the (SRSO)/SiO2 multilayer (ML) grown by reactive magnetron luminescence. sputtering and then annealed at high temperature to induce the formation of Si-nc. The mean size of the Si-nc is 3-4 nm and I. INTRODUCTION the density is about 3.5xl108 cm-3 as deduced from high The research on silicon nanoclusters (Si-nc) based materials resolution TEM micrographs (Figure 1). More details on the for photonics applications has many branches since different sample growth can be found elsewhere [12][13]. useful properties can be exploited. The first motivation to the study of Si-nc was their highly efficient visible light emittin