Geometric optics analysis of modal propagation in graded-index cylindrical fiber

Abstract

Methods of geometric optics are used to characterize a multimode optical fiber. The discrete propagation modes are derived by applying the phase resonance constraint to equations of constant phase surfaces. This constraint provides a very clear geometrical interpretation of discrete propagation modes, and provides a link between the well known Wentzel, Kramers, Brillouin (WKB) method and geometric optics.

Geometric optics analysis of inverted graded index fibers

“…Although an accurate study of light propagation in optical fibers would require solving Maxwell's equations [1], it is possible to make use of approximations based on geometric optics if highly multimode fibers are involved. This approach has successfully been applied to step-index and graded-index fibers [2][3][4][5][6], as well as to more recent multi-step [7] and multicore [8] fibers.…”