A fast Time Domain Travelling Wave method for simulation of Quantum Dot lasers and amplifiers

The Time Domain Travelling Wave (TDTW) model has been applied to a large number of Quantum Well lasers with complex multi-section structure. Even for the Quantum Dot lasers and amplifiers, the TDTW approach reveals to be a very powerful tool, because it can be used to reproduce with good accuracy several experiments performed in the lab (eg: pump-probe experiments in SOA [1]) or to simulate and interpret the performance of various QD lasers [2,3]. However, when we move to the QD case and we need to include peculiar properties of the QDs (e.g: wide emission spectrum due to ground and excited states emission, multipopulation rate equation, phase dynamics...) the TDTW tool becomes practically useless because it requires huge simulation times (see Fig.1). This simulation time is unacceptable particularly when we need to run large number of simulations planned to reproduce for example several different characteristics of the same device (ie: optical emission spectra, power versus current characteristics, small and large signal modulation with electrical or external optical signals etc...) or when we need to design or optimize a new device.