In recent years, random lasing materials (e.g. powders, porous media, precipitates in solution, or photonic crystals with impurities) have been extensively studied experimentally. Pumping energy into these systems causes them to re-emit multi-mode coherent light, with a spectrum displaying randomly arranged peaks in frequency. Starting from the structure and geometry of the atoms and molecules that scatter the light waves, one would eventually want a theory that predicts the onset, the nature and the features of the light modes and answering the following questions.
- What shape and size do light modes display in space ?
- In which dimension and under which conditions do they localize because of disorder?
- On which frequencies do light modes emit in cavity-less media?
- Can there be a random laser pulse in time?
- Do competing random laser modes phase-lock as in multimode standard lasers?
- How strong is the coupling magnitude and how is it related to the coupling modes spatial overlap and the etherogeneous optical susceptibility?