1.1. Introduction

The principal motivations for the emergence of photonic crystals can be summarized in one single word, ?-Photonics , which means the control of photons at the wavelength scale. The harnessing of light has always been central in the field of human endeavor: one may call to mind, for example, the destruction of the Roman fleet by the blazing mirrors of Archimedes at the siege of Syracuse in 215 BC.

Generally speaking, the harnessing of light consists of structuring the space where it is meant to be confined; but there are intrinsic limitations which are related to the undulatory nature of light and which have been formulated in the famous Maxwell equations of 1873, providing a consistent picture of the experimental data then available. These limitations lie at the heart of ?-Photonics, whose definition could be the control of photons within the tiniest possible space over the longest possible time: this implies structuring space at the wavelength scale, which is the sub-micron range for the optical domain.

Microphotonics or Nanophotonics?

The reader will have understood that the word ?-photonics refers simply to Microphotonics in the optical regime. We will use the term Microphotonics throughout this chapter, given that the average size of photonic structures under consideration is micro-metric. Yet, the size resolution to be considered for the design as well as for the fabrication of efficient practical photonic devices is the nanometer.

The nanometric control of the size of...