Reflection of the surface mode from an abruptly ended W-fibre

The paper deals with the problem of surface mode reflection from an abruptly terminated W-fibre. The problem is solved by use of the modified variational technique and the quasi-vector approximation. The results obtained are compared with those developed by the scalar optics theory and by the effective-refractive-index method. It is shown that the approximate techniques do not present a detailed description of the reflection characteristics