Optisen puolijohdevahvistimen pituuden optimointi tehonkulutuksen minimoimiseksi

Semiconductor optical amplifiers (SOAs) are important optoelectronic components with many applications. This thesis focuses on the application of SOAs as integrated amplifiers in an optical interconnect system. In order to meet the amplification requirement of the application, SOAs of different lengths may be used and operated with different injection currents. Different component lengths result in varying power consumption which is wanted to be kept as low as possible. The aim of this thesis was to develop a method to find the optimal SOA length with the lowest power consumption. The length optimization was performed by fabricating and characterizing ridge waveguide lasers with a geometry similar to that of the target SOAs. Three different parameters - operating voltage, modal gain and saturation power - and their dependence on the injection current density were determined. Antireflection coating using atomic layer deposition was applied to the components to obtain modal gain data at high injection current densities. Two different SOA materials were studied: a novel GaInNAsSb/GaAs structure emitting around 1300 nm and a more traditional AlGaInAs/InP structure emitting around 1550 nm. The target application had four different operation cases with varying amplification targets. A component length resulting in the minimum power consumption was succesfully determined for all the cases and for both materials.