Optical fiber tapers are used to collect photoluminescence emission at ~1.5
um from photonic crystal cavities fabricated in erbium doped silicon nitride on
silicon. Photoluminescence collection via fiber taper is enhanced 2.5 times
relative to free space, with a total taper collection efficiency of 53%. By
varying the fiber taper offset from the cavity, a broad tuning range of
coupling strength is obtained. This material system combined with fiber taper
collection is promising for building on-chip optical amplifiers.Comment: 10 pages, 7 figure