Nonlinear Non-Hermitian Skin Effect and Skin Solitons in Temporal Photonic Feedforward Lattices

TL;DR

This paper demonstrates the nonlinear non-Hermitian skin effect in a photonic lattice using optoelectronic feedforward, revealing enhanced localization, skin solitons, and applications in optical routing.

Contribution

It introduces the first experimental realization of nonlinear NHSE in a Kerr nonlinear photonic lattice with tunable nonlinearity via feedforward.

Findings

Nonlinear NHSE shows improved localization and robustness.

Kerr self-trapping can inhibit NHSE transport and create skin solitons.

Designed an optical router with tunable output port.

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.