EVANESCENT COUPLING OF A DIPOLE TO A PHASE-CONJUGATE MIRROR

We study near field coupling of dipole radiation to a phase conjugate minor and show the following. The near field coupling which scales as an inverse cubic power of the distance of the dipole from the phase conjugate mirror leads to a significant narrowing of the dynamical response. For sufficiently short distances the evanescent coupling can lead to the onset of parametric instability, The calculations suggest the possibility of thresholdless lasing in resonators with phase conjugate mirrors due to narrowing and subsequent parametric gain.