Nonlinear wave propagation in a bistable optical chain with controlled non-reciprocal coupling

Bistable coupled systems can exhibit nonlinear waves. Domino waves represent a straightforward example of nonlinear waves in everyday life. Domino waves are observed in extended bistable chains where a domino has two stable equilibria: vertical and horizontal. These elements are coupled reciprocally. Namely, if one exchanges the role of emitter and receiver, the observed propagation is the same. Nonetheless, there is no knowledge of the impact of non-reciprocal coupling on the propagation of nonlinear waves. Based on an experiment using a liquid crystal light valve (LCLV) with optical feedback, non-reciprocal nonlinear wave propagation can be studied in a one-dimensional chain discrete model. A spatial light modulator and an optical feedback loop let us control the initial conditions and non-reciprocal coupling, respectively. The nonlinear waves' spatiotemporal evolution and velocities are also characterized. A discrete model of the bistable system is derived using a tight binding-like approach for the LCLV with non-reciprocal optical feedback. Numerical simulations of the non-reciprocal coupled bistable system reasonably agree with experimental observations.