Making light work in photonic crystals

Photonic crystal fibre (PCF) is a single-material all-silica structure. Initially proposed by the author in 1991, the first working example was reported at the Optical Fiber Communications Conference in 1996. In place of the conventional core and cladding, an array of microscopic air holes runs along the entire length of the fibre. Depending on the design, light can be trapped by two distinct mechanisms: A modified form of total internal reflection (at a filled-in hole) or by a photonic bandgap (e.g., at an enlarged hole). These unconventional fibres have led to a series of breakthroughs that is radically enhancing the performance of optical fibres. The disruptive implications of the new technology are just beginning to be worked out.