The international cabling standard ISO/IEC 11801 divides multimode fibers into three types: OM1, OM2, and OM3. OM1 refers to traditional 62.5μm multimode fiber; OM2 refers to traditional 50μm multimode fiber
OM3 refers to the newly added 50μm 10 Gigabit multi-mode fiber; single-mode fiber is divided into two types: OS1, OS2. OS1 refers to the optical fiber that meets the optical fiber standards G.652A and G.652B, that is, the traditional single-mode optical fiber
OS2 refers to the fiber that meets the fiber standards G.652C and G.652D, and is also called single-mode zero-water peak fiber or single-mode low-water peak fiber. As the optical fiber technology matures, OS1 will be gradually replaced by OS2. However, the currently published Ethernet technical standards do not distinguish between OS1 and OS2. It is expected that the two will be distinguished in the next-generation 40G and 100G standards. The OS2 single-mode fiber can be better applied to the next-generation Ethernet standard.
OS1 single-mode fiber is mainly used for the O band (Original band-Original): 1325-1360nm and C band (Conventional band-Conventional): 1530-1560nm. As OS2 single-mode fiber overcomes the influence of the water peak of 1383nm, its applicable bands are extended to four, namely: O band (original band-Original): 1325-1360nm, E band (extended band-Extended): 1360 -1460nm, S band (short band-Short): 1460-1530nm and C band (conventional band-Conventional): 1530-1560nm, as for L-band (long band-Long): 1650-1675nm and U-band (ultra-long band- Ultralong): 1625-1675nm is not defined in the standard OS2 fiber.
