Waveguide-based two-dimensional photonic crystals

Summary form only given. Photonic crystals (PCs) in the optical range are slowly emerging from a conceptual phase to physical implementations. In the past few years, several 3D fabrication techniques have been demonstrated which lead/should lead to the observation of full 3D bandgaps. However, 3D PCs do not easily either yield sizeable physical effects such as the control of spontaneous emission or lifetime changes, or provide structures that could be exploited in the optoelectronics field. On the other hand, full 3D photonic bandgaps are not a requirement for many applications. What is needed is 3D confinement, as can for instance be provided by the association of vertical in-plane waveguiding, by a membrane structure or by a heterostructure waveguide, and of horizontal 2D PC-based light propagation control. 2D PCs in thin-slab or waveguide structures indeed open a number of new possibilities in active optoelectronics or in the realization of various passive integrated optics components such as mirrors, waveguides, micro-resonators, couplers, etc.