Abstract
We evaluate the dipole decay rate inside a hollow high quality factor Q rectangular quantum dot activity. The cavity modes are quantised, allowing the position-dependent spontaneous emission rate to be evaluated, leading to the possibilities of enhanced and inhibited decay rates. In particular, in the small size limit, especially when all sides of the cavity are less than lambda (the electric dipole transition wavelength), we show that the spontaneous emission process is possible only via a few cavity modes. The results are illustrated with reference to sodium atoms inside a sub-micron cavity.