Calculation of the optical characteristics of a bent waveguide

A multimode fiber waveguide bent along the circumference of a circle is considered. It is assumed that initially the refractive index profile is rectangular. A study is made of the geometry of meridional rays making allowance for the refractive index gradient resulting from bending. A calculation is made of the change in the entry aperture of the waveguide and in the "mean free path" of a ray between reflections, and of the relative increase in the optical path and number of reflections of a ray during its passage along the whole of the fiber.