Short pulse transmission characteristics in multi-contact SOA

An experimental characterisation of a multi-contact semiconductor optical amplifier using ultrashort optical pulses is presented. The SOA in question allows the injection of bias current through multiple independent electrical contacts, allowing the direct control of the carrier density. Picosecond-scale optical pulses are transmitted through the SOA. The non-linear effects on the pulse shape and spectrum after transmission are determined. It is found that the bias current distribution in the SOA is a significant factor in determining the extent of the non-linearities affecting the pulses. Additionally, amplification of negatively chirped pulses in the saturated SOA is found to reduce the spectral width of the pulses.