Theory of Exceptional Points of Degeneracy in Uniform Coupled Waveguides and Balance of Gain and Loss
Theory of Exceptional Points of Degeneracy in Uniform Coupled Waveguides and Balance of Gain and Loss
We present a transmission line theory of exceptional points of degeneracy (EPD) in coupled-mode guiding structures, i.e., a theory that illustrates the characteristics of coupled electromagnetic modes under a special dispersion degeneracy condition, yet unexplored in the contest of gain and loss. We demonstrate the concept of Parity-Time ($\cal{PT}$)-symmetry in …