Photonic Crystals: Towards a Novel Generation of Integrated Devices for Chemical and Biological Detection

A new class of materials, called Photonic Crystals (PhCs), affects a photon's properties in much the same way that a semiconductor affects an electron's properties. PhCs, in fact, possess a photonic bandgap, which means that light of certain wavelengths cannot propagate through them. These structures have very interesting properties of light confinement and localization together with the strong reduction of the device size, orders of magnitude less than the conventional photonic devices, allowing a potential very high scale of integration. Due to their unique features, these structures can possess unique characteristics that enable the structures to behave like optical waveguides, high Q resonators, selective filters, lens or superprism, just to name a few. The ability to mold and guide light leads naturally to novel applications in several fields including optoelectronics, telecommunications. The authors present in this chapter an introductory survey of the basic concepts of this new technology with particular emphasis on their applications for chemical and biological sensing.