Dynamics of Frequency Combs

Periodic optical waveforms - known as frequency combs (FCs) - have equidistant spectra with a constant phase relationship. Nowadays, they lie at the heart of numerous applications such as high precision spectroscopy, frequency generation, optical clocks and research on fundamental physics. Hence, the ability to coherently control and generate FCs on demand is of utmost importance. We focus our research on frequency combs in semiconductor lasers. By aiming on both the development of new theoretical models and their efficient numerical implementation, we are able to quantitatively describe the complex spatio-temporal evolution of the light inside the highly nonlinear and dispersive laser medium. Our results form the cutting edge of research and describe both the formation of ultrashort light pulses in amplitude modulated FCs and also the self-starting frequency modulated FCs.

Electronic Band Structure and Carrier Transport

Semiconductor heterostructures are powerful tools for the realization of versatile lasers and detectors in the infrared region. Modelling of their band structure and electronic transport is important in order to enhance their performance capabilities and their high frequency modulation characteristics. We are developing a self-consistent simulation software based on the multiband kp theory that incorporates all relevant carrier scattering mechanisms. The work is focused on the highly efficient numerical implementation and extension of the functionalities.