Predicting modes of operation in quantum dot mode-locked lasers using a delay differential equation model

Semiconductor passively mode-locked lasers are of broad interest due to their potential applications as sources of ultra-short, high frequency light pulses. In spite of the complex dynamics of such devices, a relatively simple delay differential equation model can reproduce the manifold modes of operation experimentally observed. Using such a model we investigate the modes of operation of passively mode-locked lasers. We calculate key model parameters from experimentally measured quantities and thus are able to reproduce experimentally observed features, such as the onset of fundamental mode-locking, pulse width and repetition rate. Despite the simplicity of the gain model used within our approach, nano-structured lasers, such as quantum-dot lasers, can be effectively described. This enables us to make predictions about device behavior in dependence of operational parameters and allows for device optimization.