We examined the properties of photonic crystals that consist of nonoverlapp
ing chiral spheres in a dielectric medium. We considered the effect of the
chiral property of the spheres on the frequency band structure of the elect
romagnetic field in the crystal and on the transmittance properties of a sl
ab of the crystal, and we estimated the optical activity of the crystal. (C
) 1999 Optical Society of America [S0740-3232(99)01002-9].