Experimental evidence of {\it Coherence Resonance} in an optical system is reported.
We show that the regularity of the excitable pulses in the intensity of a laser
diode with optical feedback increases when adding noise, up to an optimal value of
the noise strength. Both phase and amplitude fluctuations of the pulses play a
relevant role in the dynamics of the system. We introduce the joint entropy of the
two variables to generalize the indicator of coherence, and we put in evidence the
mechanism of destruction of the excitable orbit after the resonance.
ps file, 580 kB
Date published: 2000
Journal: Physical Review Letters
Volume: 84
Page: 3298-3301
Nonlinear Science and Statistical Physics Photonics
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