Ghost Resonance in an Excitable Semiconductor Laser

It will be shown show both experimentally and numerically a ghost
resonance in the sudden power dropouts exhibited by a semiconductor laser
subject to optical feedback driven by two simultaneous weak
periodic signals. The small signal modulation conspires with
the complex internal dynamics of the system to produce a resonance at a
ghost frequency, i.e. a frequency that is not present in the
driving signals.