OS1 and OS2 single-mode fiber overview

Both OS1 and OS2 optical fibers are single-mode optical fibers specified by ITU-T standards (i.e., ITU-T recommendations, which describe the geometric characteristics and transmission characteristics of single-mode optical fibers and multi-mode optical fibers). In the ITU-T standard, OS1 single-mode fiber is a traditional single-mode fiber that complies with G.652.A and G.652B (conventional) fiber standards; OS2 single-mode fiber is a type that complies with G.652C and G .652D fiber standard single-mode fiber, also known as low water peak fiber or zero water peak fiber, is commonly used in CWDM networks. In addition, the latest G.657A1 optical fiber standard released by ITU-T specifies a bend-insensitive single-mode optical fiber with excellent bending resistance. Now some optical fiber suppliers on the market can provide OS2 single-mode optical fiber that meets this standard. optical fiber. "Understanding the ITU-T standards of different optical fibers" This article introduces several different ITU-T standards of optical fibers. If you are interested, you can read it.

What is the difference between OS1 and OS2 single-mode fiber?

In addition to the slight differences in geometric characteristics and transmission characteristics mentioned above, OS1 and OS2 single-mode optical fibers also have the following differences, as detailed below:

Cable structure

OS1 single-mode optical fiber usually adopts a tight tube structure and is designed for indoor applications. It is generally covered with a protective sheath on the outside and wrapped with a bundle of flexible fiber polymer (such as aramid yarn) in the middle. However, OS1 single-mode optical fiber The core and cladding of optical fiber are made of glass, which cannot be bent and is fragile. The coating layer plays a protective role and can extend the service life of the optical fiber.

The OS2 single-mode fiber is placed helically in a semi-rigid tube so it can stretch without bending the inner fiber, which would damage it under the enormous pulling force. OS2 single-mode optical fiber usually adopts loose tube design, which is more suitable for outdoor applications. In some harsh outdoor environments, armored or industrial-grade OS2 single-mode optical fiber with a more robust cable structure is usually used.

Attenuation value

The attenuation value of OS1 single-mode fiber is greater than that of OS2 single-mode fiber. Normally, the maximum attenuation value of OS1 single-mode fiber in the 1310nm and 1550nm bands is 1.0db/km, while the maximum attenuation value of OS2 in this band is 0.4db/km.

Transmission distance

The transmission distances of OS1 and OS2 single-mode optical fibers are different. The longest transmission distance of OS1 single-mode fiber is 10km, while the longest transmission distance of OS2 single-mode fiber can reach 200km. In addition, both OS1 and OS2 single-mode optical fiber can achieve transmission rates from 1G to 10G at different transmission distances, but the difference is that OS2 single-mode optical fiber can also be used for 40G/100G Ethernet transmission.