High-strength long-length single-mode fiber synthesized by the VAD method

Long-length high-strength single-mode fibers were fabricated from large preforms made by the VAD process. The longest piece lengths produced at 2-percent (1.4 GPa) strain prooftesting and 5-percent (3.5 GPa) strain prooftesting are 41.7 km and 15.6 km, respectively. These are the longest length fibers in the world at their respective strain prooftesting levels. The transmission losses for the 41.7-km fiber are 0.36 dB/km at 1.3 μm and 0.22 dB/km at 1.55 μm.