Hazel B. Matthews

Towards Superior Transmission Performance in Submarine Systems: Leveraging UltraLow Attenuation and Large Effective Area

This paper expands our previous work on record-low attenuation of 0.1460 dB/km, measured on a silica-core fiber with 148 μm2 effective area. We describe the technology used to achieve such low level of attenuation and quantify other span loss characteristics, such as maintaining ultralow attenuation after cabling and splice loss reduction using “bridge” fiber and tapering techniques. We also show that a superior transmission performance in submarine networks is achieved using a combination of ultralow attenuation and large effective area, and discuss the impact of span length on system performance. We finally demonstrate that the reduction in fiber attenuation provides an additional benefit of lower optimum power into the fiber, therefore, relaxing the maximum output power requirements of submarine EDFAs.

11 – Submarine fibers

Optical fibers provide the backbone of telecommunication systems, particularly undersea networks where low loss and large effective area are essential for enabling data transmission over thousands of kilometers. In this chapter, we present an overview of optical fibers used for undersea communications. These fibers include the non-zero-dispersion-shifted fibers (NZ-DSFs) and the negative dispersion slope fibers used in dispersion-managed systems and the ultra-low-loss fibers which are now being deployed in coherent systems. We briefly discuss the design approach and manufacturing process, as well as the origins and importance of key fiber properties such as attenuation, dispersion and effective area. The interplay between these fiber parameters will be illustrated in examples of effective area management, dispersion compensation, and dispersion-managed fibers.