Figure 3
From: Absence of Exceptional Points in Square Waveguide Arrays with Apparently Balanced Gain and Loss
Numerical results of the evolution of eigen-indices with increasing unperturbed gain/loss factor g for double coupled waveguides.
(a) Real and (b) imaginary parts of four supermodes neff (Fig. 1(a)) as a function of g, obtained by FEM numerical simulation. For each mode without gain/loss injection, i.e., g = 0, the field distribution Ez in the transverse section and longitude surface are shown in (c–f). For the group of (e,f), as g is increasing from the unbroken to the broken phase, the field distributions are in accordance with (g,h), (i,j) and (k,l), respectively. (m–r) transverse modes corresponding to (c,d).
