  We investigate experimentally and theoretically the lasing behavior of
dielectric microcavity lasers with chaotic ray dynamics. Experiments show
multimode lasing for both D-shaped and stadium-shaped wave-chaotic cavities.
Theoretical calculations also find multimode lasing for different shapes, sizes
and refractive indices. While there are quantitative differences between the
theoretical lasing spectra of the stadium and D-cavity, due to the presence of
scarred modes with anomalously high quality factors, these differences decrease
as the system size increases, and are also substantially reduced when the
effects of surface roughness are taken into account. Lasing spectra
calculations are based on Steady-State Ab Initio Laser Theory, and indicate
that gain competition is not sufficient to result in single-mode lasing in
these systems.
