Abstract

With the recent advances in nanofabrication capabilities, new micro- and nano-laser systems have emerged, such as microcavity lasers, random lasers and polaritonic lasers. These systems are characterized in certain operational regimes by complex modal structure and strong mode-mode interactions, highlighting the inadequacies of current theory. In this talk, I will discuss theoretical tools that we have developed to treat strong mode-mode interactions in non-equilibrium systems by accessing directly the steady state. After touching on some of the controversy in the past decade on lasing in weakly disordered lasing media (“diffusive random lasers”), I will show that in these systems, lasing dynamics is dominated by strong non-linear interactions between modes. Minute spatial fluctuations in the pump power are found to lead to large fluctuations in the steady-state lasing intensities, while the lasing frequencies remain surprisingly immune, in agreement with recent experiments.