Abstract
An array of non-Hermitian optical waveguides can operate as a laser or as a coherent perfect absorber, which corresponds to a spectral singularity of the underlying discrete complex potential. We show that all lattice potentials with spectral singularities are characterized by the universal form of the gain-and-loss distribution. Using this result, we systematically construct potentials characterized by several spectral singularities at arbitrary wavelengths, as well as potentials with second-order spectral singularities in their spectra. Higher-order spectral singularities demonstrate a greatly enhanced response to incident beams, resulting in the excitation of high-intensity lasing modes.
© 2020 Optical Society of America
Full Article | PDF ArticleMore Like This
Jinal Tapar, Saurabh Kishen, and Naresh Kumar Emani
Opt. Lett. 45(18) 5185-5188 (2020)
Vladimir V. Konotop, Barry C. Sanders, and Dmitry A. Zezyulin
Opt. Lett. 44(8) 2024-2027 (2019)
Dmitry A. Zezyulin, Herwig Ott, and Vladimir V. Konotop
Opt. Lett. 43(23) 5901-5904 (2018)