Fig. 3: Front propagation in a bistable optical chain with nonreciprocal coupling.
From: Nonlinear wave propagation in a bistable optical chain with nonreciprocal coupling
a Spatiotemporal diagrams of chains of bistable optical systems with different shifted optical feedback controlled by the displacement α. The cross with error bars show the moment in which the cells of the bistable system light up. The linear regression and the standard deviation of the crosses are represented by the segmented lines and the error bars, respectively. Most precisely, the error bars represent the least squares error of the linear fit t = (x − xc)/v + t0, where xc is the position of the central cell and t0 is the time at which the central cell is light up. The segmented lines show a linear fit for the propagation of fronts in the spatiotemporal diagram. The scale bars indicate the cell size. b Front speed versus the shift of the optical feedback α. The blue and red curves show the speed of the front towards the right (VR) and left (VL) flank, respectively. \(\alpha ={\alpha }_{m}^{\pm }\) accounts for the critical value for which it is measured the maximum speed. The symbols squares, hexagons, and stars account for the spatiotemporal diagrams shown in panel a. c Snapshot of a single bistable cell and corresponding mid-line profile in the dark (ground) and bright (excited) state. The scale bar shows the cell size.
