Lasing in disordered media

Summary form only given. We developed a theoretical model for random lasers based on the eigenmodes of a random medium. Lasing with non-resonant feedback corresponds to lasing in a set of coupled eigenmodes, while lasing with resonant feedback corresponds to lasing in individual eigenmodes. We derived the dependence of the lasing threshold pump intensity on the transport mean free path, the pump area, and the sample size. The theoretical predictions agrees with the experimental results.