Mechanisms of grating formation in optical waveguides

Despite the proliferation of materials in which waveguides may be formed, the vast majority of grating work is still carried out using silica-based optical fibres. This work is being driven by the fibre telecommunications and sensor markets, where there are requirements for low-loss, low-cost filters which are robust and easy to manufacture. There has yet to be serious interest in fibre gratings in other materials, although some devices are starting to appear such as the chalcogenides and ZBLAN fluoride based glasses. A full understanding of the underlying process to grating formation is not yet available.