  Ray optics has proven to be an effcient and versatile tool to describe
dielectric optical microcavities and their far-field emission based on the
principle of ray-wave correspondence. Whereas often the well-known ray-optics
at planar interfaces yields reasonable results, semiclassically and
boundary-curvature induced corrections will become more important as the cavity
size is further reduced. In this paper we summarize the various ray optics
descriptions of optical microresonators, paying in addition special attention
to the differences that arise between chaotic vs. non-chaotic (integrable or
nearly integrable) resonator geometries, respectively. Whereas the far-field
pattern in the chaotic case is known to be determined by the overlap of the
unstable manifold with the leaky region, it results from the emission of
trajectories with the smallest nonzero decay rates in the non-chaotic
situation. We present an enhanced ray optical description, extended by
wave-inspired (semiclassical) corrections, and discuss their consequences for
the ray dynamics. In particular we find clear indications for the presence of
attractors resulting from the non-Hamiltonian character of the extended ray
dynamics in phase space. We illustrate their impact on the far-field emission
and show that it can considerably differ from the conventional ray description
result.
