Oscillation structures in the spontaneous emission rate of an atom in a medium with refractive index n between mirrors: a solvable model

摘要

We study the multi-periodic oscillations in the spontaneous emission rate ofan atom in a medium with refractive index n sandwiched between two parallelmirrors. The oscillations are not obvious in the analytical formula for therate derived based on Fermi's golden rule but can be extracted using Fouriertransforms by varying the system scale while holding the configuration. Theoscillations are interpreted as interferences and correspond to variousclosed-orbits of the emitted photon going away from and returning to the atom.This system provides a rare example that the oscillations can be explicitlyderived by following the emitted wave until it returns to the emitting atom. Wedemonstrate the summation over a large number of closed-orbits converges to therate formula of golden rule.