Abstract

Since the advent of vertical cavity surface-emitting lasers, a renewed interest has also emerged for the spontaneous emission from Fabry-Pérot microcavities. Changes in spontaneous emission characteristics in a 1D microcavity were predicted long ago,¹ but have been demonstrated only recently in the optical domain for solid-state, e.g. semiconductor, structures where changes in spectral purity, lifetime, and emission intensity were observed.² However, the interpretation of these effects is somewhat obscure, because these structures are highly absorbing and often involve band-to-band, rather than atomic, transitions. In the present study, we use optically transparent Si/SiO₂ cavities, consisting of two coplanar Si/SiO₂ distributed Bragg reflectors (DBR) around a (λ/2) SiO₂ active region, which was doped with ~0.2 at.% Er³⁺ ions through MeV ion implantation. The Er³⁺ ions in SiO₂ exhibit a sharp, atomic-like, intra-4f transition around λ_em=1.54 μm, which is effectively shielded by the outerlying filled 5s² and 5p⁶ shells. Recently, we reported on the considerable enhancement of the spontaneous emission intensity out of such an Er-doped microcavity.³ In this paper, we present a more detailed study of the modified spontaneous emission, including fluorescence decay measurements to study the effect of the cavity on the spontaneous emission rate.

© 1993 Optical Society of America