Nanochannel glasses, containing regular hexagonal closed packed arrays
of parallel air cylinders with periods varying from 0.25 to 0.19 mu m
, are shown to display photonic band-gap behavior throughout the visib
le that is consistent with previously published theory. Immersing the
glasses in liquids of various refractive indices allowed observation o
f the buildup of the bands as a function of cylinder dielectric consta
nt.