Spectral singularities of a complex spherical barrier potential and their optical realization

Mostafazadeh A., Sarisaman M.

PHYSICS LETTERS A, vol.375, no.39, pp.3387-3391, 2011 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 375 Issue: 39
  • Publication Date: 2011
  • Doi Number: 10.1016/j.physleta.2011.07.052
  • Journal Name: PHYSICS LETTERS A
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.3387-3391
  • Keywords: Complex potential, Spectral singularity, Zero-width resonance, Gain medium, Threshold gain, Spherical dye laser


The mathematical notion of a spectral singularity admits a physical interpretation as a zero-width resonance. It finds an optical realization as a certain type of lasing effect that occurs at the threshold gain. We explore spectral singularities of a complex spherical barrier potential and study their realization as transverse spherical electromagnetic waves emitted by a gain medium with a spherical geometry. In particular, for a typical dye laser material, we obtain a lower bound on the size of the gain medium for the occurrence of this kind of spectral singularities. (C) 2011 Elsevier B.V. All rights reserved.