Hi there!
This time, I will share with you the types of optical fiber!
Since the single-mode optical fiber has advantages of low internal attenuation, large bandwidth, easy upgrade, and capacity expansion, and low cost, it is internationally agreed that DWDM systems will only utilize single-mode fiber as transmission media. At present, ITU-T has defined four types of single-mode optical fiber with different designs in Recommendations G.652, G.653, G.654, and G.655.
1. G.652 fiber
G.652 fiber is currently a single-mode fiber for extensive use, called 1310nm property optimal single-mode fiber and also called dispersion unshifted fiber. According to the refractive index cross-section of the core, it can also be divided into two categories: matched cladding fiber and depressed cladding fiber. They have similar properties. The former is simple in manufacturing but has relatively larger macro bend loss and microbead loss while the latter has larger connection loss.
2. G.653 fiber
G.653 fiber is called dispersion-shifted fiber or 1550nm property optimal fiber. By designing the refractive index cross-section, the zero dispersion point of this kind of fiber is shifted to the 1550nm window to match the minimum attenuation window. This makes it possible to implement ultrahigh speed and ultra long-distance optical transmission.
Although G.653 fibers have the advantage of zero dispersion at 1550 nm, four-wave mixing effect (FWM) occurs, which has a serious impact on WDM. G.653 is the best choice for SDH networks.
3. G.654 fiber
G.654 fiber is a cut-off wavelength shifted single-mode fiber. This kind of fiber is mainly designed to reduce the attenuation at 1550nm. Its zero dispersion point is still near 1310nm. The dispersion at 1550nm is relatively high, up to 18ps/(nm. km). So single longitudinal mode laser must be used to eliminate the effect of the dispersion. G.654 fiber is mainly used for submarine optical fiber communication with a very long regenerator section distance.
4. G.655 fiber
G.655 fiber, a nonzero dispersion-shifted single-mode optical fiber, is similar to G.653 fiber and preserves certain dispersion near 1550nm to avoid the four-wave mixing phenomenon in DWDM transmission. It is suitable for DWDM system applications.
Except for the above-mentioned four types of standardized fiber, a large effective area fiber suitable for higher capacity and longer distance has emerged. Its zero dispersion point is near 1510mm and its effective area is up to 72 square mm. Therefore, it can effectively overcome the nonlinear effects and is especially suitable for DWDM system applications based on 10Gbit/s.
For more information about the cables, please click the following links：
https://forum.huawei.com/enterprise/en/cat6-and-cat7/thread/762527-875
https://forum.huawei.com/enterprise/en/common-fiber-types/thread/585380-875
Thank you!
