OPTICAL FIBRE FILTERS

摘要

A method of fabricating a band-processing optical fibre filter having a centre wavelength .lambda.0', the method comprises (i) radius-reducing a mismatched multi-core optical fibre having a core phase matching wavelength (before radius reduction) of .lambda.0 and a radius (before radius reduction) of a0, to a reduced redius Ra0, where R=.lambda.0'/.lambda.0; and (ii) providing light input and output connections to a section of the radius-reduced multicore fibre so that input light is launched into one of the cores of the multicore fibre section and output light emerges from one of the cores of the multicore fibre section.