Optical Solitons and Frequency Comb Generation - Abstract
It is shown that in planar waveguides with weakly nonlinear active core and absorbing boundaries there can exist continuous families of solitons. Stable propagation of TE and TM-polarized solitons is accompanied by attenuation of all other modes. If the linear spectrum of the waveguide possesses an exceptional point an originally focusing (defocusing) material nonlinearity may become effectively defocusing (focusing). This occurs due to the geometric phase of the carried eigenmode when the surface impedance encircles the exceptional point. The existence of an exceptional point can also result in anomalous enhancement of the effective nonlinearity.