A General Characterization of Splice Loss for Multimode Optical Fibers

One factor which must be considered in the development of fiber optical communication systems is the effect of fiber core parameter manufacturing variations on splice loss. These intrinsic fiber core parameters 1 are the maximum index-of-refraction difference between 2163 core and cladding, A, the index of refraction profile parameter, a, the radius, R, and core ellipticity, e. The development of a phenomenological Gaussian point loss model 2 allows an approximate analytic treatment of the loss induced by a butt-joint splice between fibers which differ in one or more intrinsic parameters. Previous models based on the uniform power distribution assumption 1 have exhibited only limited agreement between calculated and measured splice loss, 3,4 whereas the Gaussian model gives good agreement with experimental data. Previous work2 developed the Gaussian point loss model and gave theoretical and experimental results for A mismatch, R mismatch and transverse offset. This model has been used to estimate system losses due to random splicing between fibers whose intrinsic parameter variation distributions are known. 5 An extension of this model to the case of index-of-refraction profile (a) mismatch or ellipticity (e), and to combinations of intrinsic factors plus transverse offset, is presented in this paper. Although the extension of the model is straightforward, the resulting calculations require the use of approximate numerical quadrature techniques applied over irregular areas of integration.