OPTICAL WAVEGUIDE AND METHOD OF FABRICATING SAME

摘要

Orthogonally polarised waves in an optical waveguide are decoupled by providing stress-induced birefringence greater than 5 x 10<-5> in the waveguide. The birefringence is achieved by providing a jacket 33 which is of non uniform thickness which upon cooling exerts a sufficient strain upon the waveguide. A single polarised wave can be supported in such a guide without decoupling. The optical fibre preform shown has a core 31, cladding 32 and outer jacket 33. Optical fibre preforms having an inner core surrounded by a cladding and an outer jacket of non-uniform thickness at least partially surrounding the cladding are prepared.