Two-dimensional photonic-bandgap structures operating at near-infrared wavelengths

Abstract

PHOTONIC crystals are artificial structures having a periodic dielectric structure designed to influence the behaviour of photons in much the same way that the crystal structure of a semiconductor affects the properties of electrons¹. In particular, photonic crystals forbid propagation of photons having a certain range of energies (known as a photonic bandgap), a property that could be incorporated in the design of novel optoelectronic devices². Following the demonstration of a material with a full photonic bandgap at microwave frequencies³, there has been considerable progress in the fabrication of three-dimensional photonic crystals with operational wavelengths as short as 1.5 μm (ref. 4), although the optical properties of such structures are still far from ideal⁵. Here we show that, by restricting the geometry of the photonic crystal to two dimensions (in a waveguide configuration), structures with polarization-sensitive photonic band-gaps at still lower wavelengths (in the range 800–900 nm) can be readily fabricated. Our approach should permit the straightfor-ward integration of photonic-bandgap structures with other optical and optoelectronic devices.