  We propose using an asymmetric resonant microcavity for the efficient
generation of an optical path that is much longer than the diameter of the
cavity. The path is formed along a star polygonal periodic orbit within the
cavity, which is stable and confined by total internal reflection. We
fabricated a semiconductor device based on this idea with an average diameter
of 0.3 mm, and achieved a path length of 2.79 mm experimentally.
