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Critical States Embedded in the Continuum
New Journal of Physics
  • Milan Koirala
  • Alexey Yamilov, Missouri University of Science and Technology
  • A. Basiri
  • Yaron Bromberg
  • Hui Cao
  • Tsampikos Kottos

We introduce a class of critical states which are embedded in the continuum (CSC) of a one-dimensional optical waveguide array with one non-Hermitian defect. These states are on the verge of being fractal and have real propagation constants. They emerge at a phase transition which is driven by the imaginary refractive index of the defective waveguide and it is accompanied by a mode segregation which reveals analogies with the Dicke super-radiance. Below this point the states are extended while above it they evolve to exponentially localized modes. An addition of a background gain or loss can turn these localized states into bound states in the continuum.

Keywords and Phrases
  • Refractive Index,
  • Waveguides,
  • Bound State,
  • Critical State,
  • Hermitians,
  • Localization,
  • Localized Modes,
  • Localized State,
  • Optical Waveguide Arrays,
  • Real Propagation,
  • Optical Waveguides
Document Type
Article - Journal
Document Version
Final Version
File Type
© 2015 Institute of Physics Publishing, All rights reserved.
Publication Date
Citation Information
Milan Koirala, Alexey Yamilov, A. Basiri, Yaron Bromberg, et al.. "Critical States Embedded in the Continuum" New Journal of Physics Vol. 17 (2015) ISSN: 1367-2630
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