Author_Institution :
Plessey Company Ltd., Allen Clark Research Centre, Towcester, UK
Abstract :
Leaky modes, particularly tunnelling leaky modes, in step-index fibres are well known, but they are also present in graded fibres, in which case they are much more likely to cause errors in calculations and measurements, for example, transmission measurements, since they cannot be distinguished by any simple means from bound modes. The possible and probable extent of their effects are calculated by simple mode theory.
