Théorie de la propagation dans les fibres multimodales déformées aléatoirement. II. Application aux fibres à saut d’indice

The paraxial ray theory applied to randomly distorted multimode optical fibers in Part I is applied here to step-index fibers with microbending. This technique provides a stationary microbending loss equal to 6,27 λ/Δ dB/unit length, where γ denotes the spectral density of the curvature process and Δthe relative index change. The product of the square of the bandwidth improvement factor by the loss in dB is equal to 0,74 dB. The role of the distortion on bandwidth is illustrated for a 10 km long fiber, excited by a lambertian source.