Quasi-periodic breathers in a system of three coupled PT-symmetric nonlinear waveguides

Abstract

A PT-symmetric model of three unidirectional coupled waveguides with Kerr-type nonlinearity and balanced gain and loss in edge waveguides is considered. During evolution, quasi-periodic breathers of two types with zero background may form in such a system. The modulation period for temporary breather oscillations strongly depends on the initial parameters of the incident wave. One type of breathers can interact quasi-elastically with each other, acquiring small changes in the amplitudes and velocities of incoming waves after a collision. The model can be useful in creating purely optical processing devices, for example, as an analog-to-digital converter.