Optical amplification studies in Si nanocrystals-based waveguides prepared by ion-beam synthesis

Light amplification has been studied in Si nanocrystals (Si-nc) based waveguides, where the active layers were obtained by ion-beam synthesis. Pump and probe measurements have been performed in both channel and rib-loaded waveguides, using short ns optical pulses from a Nd:Yag laser for pump and continuous probe signals at 650, 780 and 830 nm. The probe was quenched by carrier absorption under pumping, except at 650 nm, where a small signal enhancement was observed. On the other hand, optical amplification at 1.54μm has been investigated in planar waveguides based on different silicates glasses codoped with Si-nc and Er, by means of the variable stripe length technique. Positive internal gain was found only in aluminium-silicates, suggesting that this can be the best host matrix for the Si-nc:Er system in order to achieve optical amplification.