Liquid Crystals into Planar Photonic Crystals

In the last decade, great effort has been devoted to the study of photonic crystals (PhCs), which are a new class of artificial materials that consist of a periodic arrangement of dielectric or metallic elements in one, two or three dimensions (see Figs. 1-2). The periodicity of these dielectric structures affects the properties of photons in the same way as the periodic potential affects the properties of electrons in semiconductor crystals. Consequently, light propagation along particular directions is forbidden within large energy bands known as photonic bandgaps. Due to such unique properties, PhCs have been proposed as a promising platform for the fabrication of miniaturized optical devices whose potential has been demonstrated both theoretically and experimentally in several applied and fundamental fields such as integrated optics and quantum optics (Busch et al., 2004; Lourtioz et al., 2005).