Scanning electron microscopy examination of telecommunication single mode fiber splices

摘要

Longitudinal sections of fused splices of different telecommunication single mode fibers were prepared and examined by scanning electron microscopy (SEM). Splices were examined for diffusion of dopant elements and for the presence of an intermediate zone. Observations in the material contrast mode obtained with backscattered electrons and X-ray microanalysis with the use of an energy dispersive spectrometer were made. Material contrast provides much better imaging of fiber cores than X-ray microanalysis and it was chosen for further studies. SEM micrographs show low amount of diffusion and good coupling of cores in splices under examination. No visible intermediate zone has been found in splices of the same fibers or fibers with similar cores. In splices of fibers with different core diameters and/or different dopant distribution the transition between cores is smooth with no visible widening of cores.