• DOI:10.1038/45960
• Corpus ID: 205046813

Laser optics: Fractal modes in unstable resonators

@article{Krmn1999LaserOF,
  title={Laser optics: Fractal modes in unstable resonators},
  author={G{\'a}bor K{\'a}rm{\'a}n and G. S. McDonald and G. H. C. New and J. P. Woerdman},
  journal={Nature},
  year={1999},
  volume={402},
  pages={138-138}
}

• G. Kármán, G. S. McDonald, +1 author J. P. Woerdman
• Published 11 November 1999
• Physics
• Nature

One of the simplest optical systems, consisting of two mirrors facing each other to form a resonator, turns out to have a surprising property. Stable resonators, in which the paths of the rays are confined between the two mirrors, have a well known mode structure (hermite–gaussian), but the nature of the modes that can occur in unstable reson-ant cavities (from which the rays ultimately escape) are harder to calculate, particularly for real three-dimensional situations. Here we show that these peculiar eigenmodes of unstable resonators are fractals, a finding that may lead to a better understanding of phenomena such as chaotic scattering and pattern formation. Our discovery may have practical application to lasers based on unstable resonators.