Experimental investigation of high-quality synchronization of coupled oscillators

We describe two experiments in which we investigate the synchronization of coupled periodic oscillators. Each experimental system consists of two iden tical coupled electronic periodic oscillators that display bursts of desync hronization events similar to those observed previously in coupled chaotic systems. We measure the degree of synchronization as a function of coupling strength. In the first experiment, high-quality synchronization is achieve d for all coupling strengths above a critical value. In the second experime nt, no high-quality synchronization is observed. We compare our results to the predictions of the several proposed criteria for synchronization. We fi nd that none of the criteria accurately predict the range of coupling stren gths over which high-quality synchronization is observed. (C) 2000 American Institute of Physics. [S1054-1500(00)01203-9].