J. A. Arnaud

Bell System Technical Journal, The  (Volume:54 ,  Issue: 8 ), pages 1431 – 1450, Oct. 1975

ABSTRACT

We evaluate the crosstalk between adjacent cores in an optical fiber that results from electromagnetic coupling. Means of reducing it are discussed. We find that a 0.5-μm-thick layer of silver can, in principle, reduce the crosstalk from −20 to −130 dB without significant increase of the loss. These theoretical results are obtained for two identical single-mode dielectric slabs. In reality, the slabs are not rigorously identical. Longitudinal fluctuations of slab thickness reduce the crosstalk by at least 40 dB. The slab spacing can accordingly be reduced from, typically, 11 to 6 μm for a constant crosstalk. If the slabs are made dissimilar with a relative difference in thickness of 10 percent, the spacing can be reduced further, to approximately 1.5 times the slab thickness. For example, a 15-μm spacing is required between single-mode dissimilar slabs if the nominal slab thickness is 10 μm, provided scattering can be neglected.

LIEN VERS  L’ARTICLE : TRANSVERSE COUPLING IN FIBER OPTICS IV : CROSSTALK