Light-Gradient-Induced Spiral Wave Drifts in a Belousov--Zhabotinsky Reaction

The dynamic behaviour of spiral tip in the light-sensitive Belousov--Zhabotinsky reaction under the influence of an externally applied light gradient was experimentally studied. The gradient causes different drifts for different spiral patterns. The centre of the spiral wave moved toward the region of lower light intensity. The direction of an additional perpendicular drift depended on the chirality of the spiral wave. The dependences of the drifting angle and the drifting velocity on light gradient have been measured.