Far-field radiation for quantum boxes located in pillar microcavities was i
nvestigated spatially and spectrally at room temperature. We have found tha
t small-diameter pillars show directional emission for the fundamental cavi
ty mode together with a spectral behavior dominated by the pillar's discret
e modal structure. These results may be important in the context of single-
photon emitters for quantum communications. (C) 2001 Optical Society of Ame
rica.