  We apply ray-optical methods to dielectric optical microcavities in the shape
of triangles made of low refractive index material. We find ray trajectories
that maximize the intensity inside the cavity to determine the far-field
emission characteristics and to complement the concept of the unstable manifold
applicable to chaotic microlasers. As these maximum intensity trajectories need
not to be periodic, we suggest that they provide a more general explanation for
emission patterns of microlasers than short periodic orbits. Further, the
geometrical optics description is extended by the inclusion of intensity
amplification along the optical path to achieve a better description of active,
lasing cavities. Far-field emission patterns of equilateral triangle cavities
obtained in this way agree well with our full electromagnetic wave simulations
and with previously reported experimental results.
