Manifestation of ray chaos in optical cavities

The correspondence between ray and wave descriptions for twodimensional chaotic open billiards describing optical cavities is reviewed. Focusing on the stadium-shaped cavity, which is well-known for its fully chaotic ray dynamics, we show how ray chaos is manifested in emission patterns, or eigenfunctions of resonances (decaying eigenmodes). The flux phase-space distribution is introduced, which not only enables one to understand the relation between ray dynamics and emission directionality, but also provides a suitable stage to study the ray-wave correspondence. We observe intrinsic localization phenomenon in each resonance, which causes discrepancies with the ray description. Nonetheless, we demonstrate that the average of many low-loss resonances reproduces the ray description very well, where one can clearly observe that signature of ray chaos (i.e., long-term effects of stretching and folding) is embedded in resonance eigenfunctions.