THE EIKONAL RAY EQUATIONS IN OPTICAL FIBERS

The traditional methods for the characterization of ray trajectories i n nonhomogeneous media are based on the Eikonal equation valid in the region of geometrical optics. To apply Eikonal theory to fiber optics requires a fairly extensive use of vector calculus and geometry. Alter natively, through a simple correspondence rule, and a few intuitive gu idelines for relating ray's to waves, an equivalent set of trajectory equations can be obtained. This approach results in the Eikonal equati ons for the space evolution of optical fiber rays which are expressed in terms of the mode analysis invariants, azimuthal mode number, and o ptical waveguide propagation phase constant.