Modeling of Double-Pass Amplification in Quantum Dot Semiconductor Amplifiers

Quantum Dots, due to their three-dimensional quantum confinement, have an electronic structure comparable to the one of atoms. This allows to have a small set of interband transitions with well-defined characteristic energies. Moreover, due to their small DOS, inversion is reached at low injections rate, thus making them a viable candidate for active medium in optoelectronics. The implementation of multiple – electrically isolated contact regions in a single SOA has allowed for a fine tuning of the output power and spectrum, by means of the gain, in each section. In this work these two concepts are combined at first to show the obtainable spectral asymmetry (and its tunability) that can be achieved with a single tapered device; at last the same device is simulated in a double-pass configuration. For this a self-consistent time-domain travelling-wave model is developed.