Improvement of detection of weak aperiodic binary signals in a bistable optical system by vibrational resonance
Vyacheslav Chizhevsky
The experimental and numerical evidence of improvement of detection of subthreshold aperiodic binary signals by the use of phenomenon of vibrational resonance in a bistable vertical cavity surface emitting laser (VCSEL) in the presence of a fixed level of noise is presented. It is shown that an additional periodic modulation with a period much shorter than a bit duration in the aperiodic input signal allows one to increase significantly a cross-correlation coefficient between the input and the output of a bistable system as well as substantially to decrease bit error rate. An experimental observation of a time lag between the input and the output of a bistable VCSEL due to effect of high-frequency modulation is shown. The effect of asymmetry of a bistable quasipotential on the detection is also studied. The numerial results are in a qualititative agreement with experimental ones.