Response of the ferrocyanide-hydrogen peroxide-sulfite system to a pulsed light

Response of the ferrocyanide-hydrogen peroxide-sulfite system to the pulsed light perturbation has been examined. A pulse light in the visible region induces two kinds of pulse response: one is a sharp spike with a threshold and the other is a relatively slow response without threshold. The autocatalytic reaction scheme involving HO2· as a key species is responsible for the observation. The proposed mechanism is compared with the excitability in the Belousov–Zhabotinsky system to characterize the nonlinearity in the present system. The present analysis suggests that the pulse response experiment is useful in revealing details of the reaction scheme.