Bends single-mode fibers

Ulrich R, Rashleigh S C and Eichoff W, Bending-induced birefringence in single mode fibers . Optics Lett., 1980, 5(6), 273-5. 

This chapter is mainly concerned with the power radiated from single-mode fibers due to bending. We first consider losses from bends of constant radius, and then examine losses due to random, but slight, curvature along the fiber, commonly known as microbends. Bending losses for multimode fibers are described by the ray methods of Chapter 9. 

We are primarily interested in radiation from the fundamental modes of bent, single-mode fibers. Within the weak-guidance approximation, the power radiated is insensitive to polarization, since p. Thus we can conveniently assume that the transverse electric field is parallel to the Z-axis in Fig. 23-2(a), i.e. orthogonal to the plane of the bend. Close to and within the core, the magnitude of the electric field on the bend is given by aj Fo (R) exp (ifiz), using the local-mode approxinution, where is the modal amplitude, Fq (R) is the... 

Sakai, J. I. (1980) Micro bending loss evaluation in arbitrary-index single-mode optical fibers. I.E.E.E. J. Quant. Elec., 16, 36-49. 

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