3D control of light in waveguide-based two-dimensional photonic crystals

Photonic crystals have seen major advances in the past few years in the optical range. The association of inplane waveguiding and two-dimensional photonic crystals (PCs) in thin-slab or waveguide structures leads to good 3D confinement with easy fabrication. Such structures. much easier to fabricate than 3D PCs open many exciting opportunities in optoelectronic devices and integrated optics. We present experiments on a variety of structures and devices. as well as modelling tools, which show that 2D PCs etched through waveguides supported by substrates arp a viable route to high-performance PC-based photonic integrated circuits (PICs). In particular, they exhibit low outer-plane diffraction losses. Low-loss waveguides, high finesse microcavities. and their mutual coupling are demonstrated.