Modification of the spontaneous emission rate of Eu3+ ions embedded withina dielectric layer above a silver mirror

We investigate the spontaneous emission rate of Eu3+ ions in an asymmetric microcavity. The cavity consists of a thin dielectric layer bounded on one side by silver and on the other by air. Samples were constructed using the Langmuir-Blodgett technique, the emitters being incorporated as a single mo nolayer within the microcavity. This technique allowed both the cavity thic kness and the position of the emitters within it to be controlled to one mo nolayer (approximate to 2.6 Ka). Measurements are presented of the spontane ous emission decay rate as a function of both the dielectric layer thicknes s and the position of the emitters within the layer. We find good agreement between our data and a classical model. The model allows us to investigate the role of the electromagnetic modes of the microcavity in controlling th e spontaneous emission decay rate of the emitters. In particular, we are ab le to evaluate the contribution each of the modes makes to the decay. We di scuss the implication these results may have in increasing the photolumines cence efficiency from microcavity based emissive devices. [S1050-2947(99)03 501-5].