Nobuyuki Yoshizawa

Stimulated Brillouin scattering suppression by means of applying strain distribution to fiber with cabling

An optical fiber cable that can suppress stimulated Brillouin scattering (SBS) has been developed. Fiber cabling expanded the Brillouin gain bandwidth from 50 MHz to 400 MHz (9 dB). The expansion was caused by a sinusoidal fiber strain distribution of +or-0.35%, which was generated in fiber by a strainholding, double-stranded cable. This work explains the relationship between the cable structure and fiber strain, as well as with the Brillouin gain bandwidth expansion. Fiber loss caused by cabling was studied and found to be small; also, the strained fiber reliability of the cable is assured with the use of carbon-coated fiber. >

Field evaluation result on hermetically coated optical fiber cables for practical application

A field trial was carried out to evaluate the overall performance of hermetically coated fibers. Three cables containing a large volume of hermetic and nonhermetic fibers were manufactured, and their initial strengths and n values were measured. The cables were installed in duct and aerial routes. Eight optical links were constructed, including dispersion-shifted and normal single-mode fibers, by splicing the installed fibers. Statistical data on optical loss and splice loss were obtained in the trial. The measured results demonstrated that the hermetically coated fiber cables had much higher fatigue resistance than conventional fiber cables, and no weak portion was found even for 500 hermetic fiber samples selected from a large volume of trial fibers. The transmission characteristics were found to be equivalent and low-loss splicing was achieved in the field. >