Waveguide dispersion in a lightguide of compressed ellipse-shaped cross-section

This paper describes the theoretical analysis for the temporal broadening o f a pulse arising due to dispersion in an optical waveguide with a cross-se ctional shape resembling an ellipse compressed along the minor axis (ECMI). Denoting the normalized frequency parameter as V, and the normalized propa gation constant as b the explicit expression for d(Vb)/dV have been derived . For this we use the appropriate coordinate systems and the boundary condi tions of the proposed waveguide under the weak guidance condition. The vari ation of d(Vb)/dV with V has also been obtained. It is seen that the curves are of the expected shapes. Moreover. the computed values of d(Vb)/dV for the ECMI are greater than those for the step index fiber. The group delay i s only slightly altered by the distortion of the circular shape to the comp ressed ellipse shape.