  We investigate numerically and theoretically the conditions leading to
soliton ejection stimulated through the scattering of bright solitons by
modulated reflectionless potential wells. Such potential wells allow for the
possibility of controlled ejection of solitons with significantly high speeds.
At the outset, we describe the scattering setup and characterise the soliton
ejection in terms of the different parameters of the system. Then, we formulate
a theoretical model revealing the underlying physics of soliton ejection. The
model is based on energy and norm exchange between the incident soliton and a
stable trapped mode corresponding to an exact solution of the governing
nonlinear Schrodinger equation. Remarkably, stationary solitons can lead to
high-speed soliton ejection where part of the nonlinear interaction energy
transforms to translational kinetic energy of the ejected soliton. Our
investigation shows that soliton ejection always occurs whenever the incident
soliton norm is greater than that of the trapped mode while their energy is
almost the same. Once the incident soliton is trapped, the excess in norm turns
to an ejected soliton in addition to a small amount of radiation that share
translational kinetic energy. We found that higher ejection speeds are obtained
with multi-node trapped modes that have larger binding energy. Simultaneous
two-soliton ejection has been also induced by two solitons scattering with the
potential from both of its sides. An ejection speed almost twice as that of
single soliton ejection was obtained. Ejection outcome and ejection speed turn
out to be sensitive to the relative phase between the two incoming solitons,
which suggests a tool for soliton phase interferometry.

Pattern Formation and Solitons;Computational Physics