As we all know, multimode fiber is usually divided into OM1, OM2, OM3, OM4 and OM5 fiber types. When it comes to single mode fiber types, it can be categorized into OS1 and OS2 fiber, which are SMF fiber specifications. OS1 and OS2 are standard single mode optical cables respectively used with wavelengths of 1310nm and 1550nm with a maximum attenuation of 1 dB/km and 0.4 dB/km. OS1 fiber is a tight buffered cable designed for use in indoor applications (such as campuses or data centers) where the maximum distance is 10 km. OS2 fiber is a loose tube cable designed for use in outdoor cases (like street, underground and burial) where the maximum distance is up to 200 km. Both OS1 and OS2 fiber optic cable support Gigabit and 10G Ethernet links. Besides, OS2 fiber can support 40G and 100G Ethernet links.