Optical event horizon-based complete transformation and control of dark solitons

We propose a manipulation approach to vary the wave speed, as well as the grayness, of dark solitons under the optical event horizon arising from the interaction between a dark soliton and a probe wave. To the best of our knowledge, the optical event horizon effect is demonstrated for the first time to be capable of inducing a reversible conversion between a black soliton and a gray one. This reversible soliton transformation and control process originates from the intrinsic competition between the probe-induced nonlinear phase shift and the internal phase of the dark soliton. In a cascaded system consisting of two optical event horizons, we also observe the new optical soliton tunneling phenomena where a dark soliton can be reset longitudinally purposely. The results may find applications in information cloaking such as effectively hiding the presence of intermediate fiber section to the receiver. (C) 2018 Optical Society of America