Arc-fusion splicing of single-mode fibers. 1: Optimum splice conditions.
The optimum conditions for arc-fusion splicing of single-mode fibers with core eccentricity of a few microns are investigated in detail. A narrow, quick fusion method, where the fiber-fused region is restricted by the narrowing of the electrode gap and the arc-discharge time is short compared with the conventional multi-mode fiber splice, is presented that will reduce the surface tension effect. The optimum values of electrode gap, prefusion time, and discharge duration are found to be 0.7 mm, 0.2 sec, and 1 sec, respectively, when the discharge current is 18 mA. The optimum pressing stroke of a fiber after the fiber end faces contact each other is determined to be 20 microm. Splice loss <0.1 dB is achieved in the present conditions for fibers with 2-microm core eccentricity and +/-3-microm o.d. discrepancy.