Study of a metal-clad optical waveguide with a periodically varying core radius

Abstract

A theoretical analysis has been made for the propagation of electromagnetic waves in an optical fiber having a conducting core-cladding boundary with the core radius varying periodically along the propagation axis. Using Maxwell's field equations, the characteristic eigenvalue equation has been derived for such a metal-clad fiber under the strong guidance condition. One finds that the r-component of the propagation vector β depends on the variable z, the axial coordinate. The modes, therefore, show a local behaviour. The variation of ∂β/∂z with the z coordinate has been computed for some low order modes.