The analytical solutions of electromagnetic wave equations for elliptical optical waveguide are studied and the mode field distribution is presented. The mode characteristic equations are derived. Circular waveguide is only a special case of elliptical waveguide. The numerical solution for the characteristic equation of first-higher-order mode is obtained. The variations of the effective refractive index as a function of the normalized frequency for various values of the core aspect ratio are presented. As the core aspect ratio increases

the normalized cutoff frequency of the first-higher-order mode decreases.