Photoluminescence from Er-doped silicon oxide microcavities

Er-doped silicon oxide (SiO:Er) thin films with Er concentrations ranging from 0.04 to ∼2.5 at.% were deposited on SiO2 and Si substrates by co-evaporation of SiO and Er2O3 under high vacuum. Electron energy filtered imaging and elemental mapping confirm the presence of amorphous Si nanoclusters surrounded by a SiO2 matrix. Steady-state and time-resolved photoluminescence indicate that the 1.54 μm emission is highest for a 0.20-at.%-Er specimen annealed at 500 °C in 95% N2 + 5% H2, yielding effective excitation cross-sections in the range of 10−16 cm2 for 476 nm excitation. To narrow and tune the Er emission, we have incorporated SiO:Er into planar microcavities with metal mirrors. The low thermal processing temperatures permitted the demonstration of simple-to-fabricate optical microcavities with intensified and directional emission in the 1480–1610 nm range.