J. Arnaud, M. Rousseau
Optical Letters, Vol 3, page 63, august 1978
The complete solution for propagation in randomly bent, circularly symmetric multimode optical fibers is given ; the paraxial-ray-optics approximation is used. This ray-optic solution is, in principle, equivalent to the power-coupled-mode equations in the continuum limit. However, none of the assumptions usually made in modal theories is needed in the ray theory. In particular, the coupling between nonadjacent modes is effectively taken into account.
LIEN VERS L’ARTICLE : RAY THEORY OF RANDOMLY BENT MULTIMODE OPTICAL FIBERS