Superlattice for photonic band gap opening in monolayers of dielectric spheres.

Dielectric spheres synthesized for the fabrication of self-organized photonic crystals such as opals offer large opportunities for the design of novel nanophotonic devices. In this paper, we show that a hexagonal superlattice monolayer of dielectric spheres exhibits an even photonic band gap below the light cone for refractive indices higher than 1.93. The use of spheres with refractive index 2.9 and diameter 0.33 mum tunes the photonic band gap to the telecommunications range (lambda=1.55 mum). As a practical example for the use of such a photonic band gap, we demonstrate the possibility of waveguiding light linearly through the monolayer.