LASING THRESHOLD AND MODE COMPETITION IN CHAOTIC CAVITIES

The lasing threshold of a multimode chaotic cavity (Linear size D much greater than wavelength lambda) coupled to the outside through a smal l hole (linear size d much less than lambda) is studied. For sufficien tly weak absorption by the boundaries, the statistical distribution of the threshold is wide, its mean value being much less than the pumpin g rate needed to compensate the average loss. The average number [N-nc ]much greater than 1 of noncompeting excited modes is proportional to the square root of the pumping rate. We use the classical model of spa tial hole burning to account for mode competition and find a reduction in the average number of excited modes to [N]=3(1/3)[N-nc](2/3).