Light-induced pattern formation in the excitable Belousov-Zhabotinsky medium

Light has been known to suppress wave activity in the vast majority of studies of excitable photosensitive Belousov-Zhabotinsky (BZ) media. In this report, we uncover that light perturbation can induce pattern formation when the dynamics of the BZ system is close to a bifurcation point, though light causes an increase of bromide concentration. The minimal light intensity for initiating pattern formation increases rapidly while the system departs from the bifurcation point. Backfiring behavior was also observed when a global light perturbation was applied to propagating waves. This study was carried out with a three-variable Oregonator model, modified to describe photosensitivity. (C) 2001 Elsevier Science B.V. All rights reserved.