  We report the spectral characteristics of fully chaotic and non-chaotic
microcavity lasers under continuous-wave operating conditions. It is found that
fully chaotic microcavity lasers operate in single mode, whereas non-chaotic
microcavity lasers operate in multimode. The suppression of multimode lasing
for fully chaotic microcavity lasers is explained by large spatial overlaps of
the resonance wave functions that spread throughout the two-dimensional cavity
due to the ergodicity of chaotic ray orbits.
