Observation of ultrahigh quality factor in a semiconductor microcavity

Observation of a very high-quality factor (Q) of ∼30,000 is reported for a planar semiconductor microcavity grown by molecular-beam epitaxy using in situ optical monitoring. The very high Qs are measured in pillars of 5–10μm diameter, and are approximately a factor of 3 higher than measured in planar structures before etching. The higher values in the pillars are ascribed to the elimination of the effects of in-plane dispersion, diffraction, and lateral inhomogeneities, thus allowing the intrinsic Q of the planar structure to be observed. Spectrally resolved mode mapping is reported, accounting qualitatively for the decrease of Q with increasing mode number in the pillars.