OS1 fiber is mainly used in the construction of indoor applications, such as campus networks and building networks, where the maximum distance is 10 km. An optical fiber is a cylindrical. Single-mode fiber optic cable (SMF) is a type of optical fiber designed to carry a single ray of light mode directly down the fiber core. Generally, single mode cable has a narrow core diameter of 8 to 10µm (micrometers), which can propagate at the wavelength of 1310nm and 1550nm. These thin strands of glass are powerhouses in transmitting data at lightning speeds.