Spectral scalability as a result of geometrical self-similarity in   fractal multilayers
  The optical spectra of fractal multilayer dielectric structures have been shown to possess spectral scalability, which has been found to be directly related to the structure's spatial (geometrical) self-similarity. Phase and amplitude scaling relations, as well as effects of finite structure size, have been derived. 
S. V. Zhukovsky, A. V. Lavrinenko, S. V. Gaponenko
physics.optics cond-mat.mes-hall