Realization of All-Optical Multistate Switching in an Atomic Coherent Medium

We have experimentally observed optical multistability (OM) in an optical ring cavity containing three-level Lambda-type Doppler-broadened rubidium atoms. The shape of the OM curve can be significantly modified by changing the power of the control laser field. An all-optical multistate switching or coding element is realized and flexibly controlled by adding a pulse sequence to the input (probe) intensity.