Nonlinear Non-Hermitian Skin Effect and Skin Solitons in Temporal Photonic Feedforward Lattices
Shulin Wang, Bing Wang, Chenyu Liu, Chengzhi Qin, Lange Zhao, Weiwei Liu, Stefano Longhi, Peixiang Lu
Abstract
Here we report the experimental demonstration of the nonlinear non-Hermitian skin effect (NHSE) in an effective Kerr nonlinear temporal photonic lattice, where the high-power requirements and lack of tunability intrinsic to optical materials are overcome by an artificial nonlinearity arising from optoelectronic feedforward. Thanks to Kerr self-trapping, the nonlinear NHSE is demonstrated to possess much better localization strength and robustness at the preferred boundary compared to the linear case. Away from the preferred boundary, Kerr self-trapping can even inhibit NHSE-induced transport and form stable skin solitons. Harnessing the nonlinearity-controlled NHSE, we judiciously design an optical router with a flexibly tuned output port. Our findings promise great applications in robust signal transmission, routing, and processing.