The photon density required for the saturation of normal-mode coupling in o
xide-apertured nanocavities is measured to be 90 photons/mum(2) by pump-pro
be experiments. The photon number is only 300 for a semiconductor nanocavit
y with a 2 mum diameter aluminum-oxide aperture, drastically reduced from 2
00 000 for a 50 mum waist on a planar microcavity. (C) 2001 American Instit
ute of Physics.