G652D and G657A2 are two ITU-T standards for single-mode optical fiber. These standards describe the transmission, mechanical and geographical properties of optical fiber. ITU-T is a sub-organization of the International Telecommunication Union (ITU), and ITU is a specialized agency authorized by the United Nations .A total of 19 single-mode fiber specifications are available.
G652D standard single-mode fiber
ITU-T G652D single-mode fiber is widely used in networks and communications. It is the latest version of the G652 category and supports coarse WDM (CWDM) transmission.
This fiber category provides zero dispersion at 1310nm wavelength. Therefore, it is designed to provide the best performance in the 1313nm band. However, G652D single mode fiber can be operated at 1550nm. The G652D can be used in both short-haul and long-haul applications.
The only downside to G652D fibers is that they cannot sustain higher bend radii. Even the best quality G652D fibers do not allow sharp bends.
Benefits of G652D Fiber:
Reduce system cost;
Provide zero dispersion and seamless splicing;
Reduce splicing loss;
Support longer optical fiber routing;
G657A2-bending reinforced fiber
G657A2 is one of the four specifications defined by ITU-T under the G657 category.
G657A2 fiber is used in network installations that require high bending resistance.
Benefits of G657A2 Fiber:
Ideal for smaller cable installation radii;
Provide better bending radius;
what is bending radius
In the fiber optic industry, the radius of curvature by which an optical fiber can be bent or twisted is called the bend radius. In simpler terms, the smallest allowable radius at which the fiber can be bent without damage is called the bend radius.
Various optical fibers have different characteristics and different physical constructions, which is why the allowable radius varies from fiber to fiber. Typically optical fibers have a specified minimum bend radius. However, it is recommended that the minimum bend radius should be kept about ten times smaller than the outer diameter of the fiber. Therefore, the bending radius of a 4mm optical fiber should not be less than 40mm.
G652D and G657A2 are compatible and can be used in series. G652D has become the standard for single-mode fiber. The G657A2 is considered to be an ideal solution for sharply curved access network cabling.