Quantum Optics with Mirrors

The close presence of a mirror can profoundly modify the spontaneous emission process. Here I describe some preliminary experiments with electrically pumped micro-cavities where we have shown enhancement and suppression of spontaneous emission into the cavity modes. We have also demonstrated modification of the spontaneous emission of photon pairs in parametric down-conversion using suitably placed mirrors. In contrast with the single photon case the mirrors can be placed at large distances from the non-linear crystal source due to the energy conservation inherent in the down-conversion of narrow band pump beam photons.