We study the polarization response of a vertical-cavity surface-emitting laser, driven simultaneously by noise and two (or more) weak periodic signals. In the bistable regime, we observe experimentally the occurrence of stochastic resonance at a frequency that is absent in the input driving signal. The presence of this so-called ghost resonance is confirmed theoretically.

The performance of a coherent perfect absorber (time-reversed laser) is limited by quantum and thermal noise. At zero temperature, the quantum shot noise dominates the signal for frequencies close to the resonance frequency and both vanish exactly at the resonance frequency. We compute the sensitivity of the absorbing cavity as a background-free detector, limited by finite signal or detector ba...

Subject of our investigation are resonance phenomena in optical cavities realized as defects in 1D gratings with piecewise constant refractive index distributions. Upon viewing the cavity as a passive open system with intrinsically leaky behavior due to the open boundaries where waves are permitted to leave the structure, the cavity can be characterized in terms of complex frequencies associate...