Unidirectional light emission from low-index polymer microlasers
  We report on experiments with deformed polymer microlasers that have a low refractive index and exhibit unidirectional light emission. We demonstrate that the highly directional emission is due to transport of light rays along the unstable manifold of the chaotic saddle in phase space. Experiments, ray-tracing simulations, and mode calculations show very good agreement. 
M. Schermer, S. Bittner, G. Singh, C. Ulysse, M. Lebental, J. Wiersig
physics.optics