Third Window (1550nm): Has the lowest attenuation of all wavelengths in silica fiber, approximately 0. It also coincides with the gain region of Erbium-Doped Fiber Amplifiers. This document outlines the specifications for a single-mode optical fiber and cable designed for use around the 1310 nm zero-dispersion wavelength, suitable for both the 1310 nm and 1550 nm regions, and compatible with analogue and digital transmission. Each corresponds to specific fiber types, reach classes, and application environments such as short-reach data center links, campus backbones, metropolitan aggregation, or long-haul transmission. This article delves into why 850, 1310, and 1550 nm are standard, what less-known regimes and tradeoffs exist, and how an OEM fiber-cable manufacturer can design and test with wavelength considerations built in. bSee IEC 60793-2-50 or ITU-T G. aOther fiber types are acceptable if the resulting ODN meets channel insertion loss and dispersion requirements.
