Evolving Microstructured Optical Fibres

Abstract

Optical fibres are not only one of the major components of modern optical communications systems, but are also used in other areas such as sensing, medicine and optical filtering. Silica microstructured optical fibres are a type of optical fibre where microscopic holes within the fibre result in highly tailorable optical properties, which are not possible in traditional fibres. Microstructured fibres manufactured from polymer, instead of silica, are a relatively recent development in optical fibre technology, and support a wide variety of microstructure fibre geometries, when compared to the more commonly used silica. In order to meet the automated design requirements for such complex fibres, a representation was developed which can describe radially symmetric microstructured fibres of different complexities; from simple hexagonal designs with very few holes, to large arrays of hundreds of holes. This chapter presents a genetic algorithm which uses an embryogeny representation, or a growth phase, to convert a design from its genetic encoding (genotype) to the microstructured fibre (phenotype). The work demonstrates the application of variable-complexity, evolutionary design approaches to photonic design. The inclusion of real-world constraints within the embryogeny aids in the manufacture of designs, resulting in the physical construction and experimental characterisation of both single-mode and highbandwidth multi-mode microstructured fibres, where some GA-designed fibres are currently being patented.