Abstract
We demonstrate steering dynamics of dark solitons in a parity–time (${\cal P}{\cal T}$)-symmetric nonlinear directional coupler (NLDC) in the presence of third-order dispersion (TOD) and intermodal dispersion (IMD). A complete switch with an excellent efficiency at a very low critical power, even lower compared to the bright soliton switching, has been observed. The numerical results show that both TOD and IMD have no effect on soliton steering in ${\cal P}{\cal T}$-symmetric couplers with coupling length $\pi /2$. But, as we increase the coupling length to $2\pi$, IMD shows marginal effects for dark soliton steering in ${\cal P}{\cal T}$-symmetric couplers, while TOD shows no impact. Additionally, we have also studied the phase-controlled switching in ${\cal P}{\cal T}$-symmetric couplers with two different coupling lengths and demonstrated its advantage over the power-controlled one.
© 2020 Optical Society of America
Full Article | PDF Article