Answer: G657A optical fiber is bending insensitive single-mode optical fiber 9/125um, fully compatible with G652D optical fiber, mainly used for FTTH optical fiber wiring. However, the biggest difference are the minimum bending radius of G657A1 is 10mm, and that of G657A2 is 7.5mm. This means that the smaller the bending radius is, the better the confined and narrow space is, but the smaller the bending radius is, the higher the cost will be. Therefore, it is the best to choose the proper optical fiber according to the specific construction environment and project budget.
There are many types of optical fiber, which can be divided into single mode fiber and multimode fiber according to the transmission mode. G657 optical fiber is a kind of single-mode optical fiber, Below will analysize single-mode optical fiber G652 and G657.
G652D is one type of G.652 fiber. G652D is the most stringent and completely down-compatible index value of all G652 levels. It has no difference with the general G652 optical fiber in structure, and is the best non-dispersion offset optical fiber for metropolitan area network at this stage.
G.652 fiber is single-mode optical fiber, capable of transmitting 1260~1360nm, 1530~1565nm, and zero dispersion point at 1310nm. G652 can be used in 1550nm optical wavelength to short distance transmission or mutual application with dispersion compensation fiber or control module.
G.652 optical fiber is a kind of single mode fiber widely used on the Internet today. ITU-T divides G.652 into four types of optical fiber, namely G.652A G.652B G.652C G.652D.
G.652A is applicable to 1Gbit/s system software transmission distance of 400km, 10Gbit/s Ethernet interface transmission distance of 40km, and 40Gbit/s system software transmission distance of 2km.
G.652B optical fiber is applicable to 10Gbit/s system software with transmission distance of about 3000km, and 40Gbit/s system software with transmission distance of 80km.
G.652C optical fiber has the same basic characteristics as G.652A, but the transmission coefficient is lower at 1550nm, and the absorption peak of water digestion around 1380nm is cleared, that is, the system software can work in the band of 1360~1530nm.
G.652D characteristics are basically the same as G.652B, and the transmission coefficient is the same as that of G.652C, that is, the system software can work in the 1360~1530nm band.
G657A2 fiber is one type of single mode bend insensitive fiber G.657A series, its bend radius minimum is 7.5mm.
G.657 is the latest member of ITU-T optical fiber series, which is based on the technical requirements of FTTx and its assembly and application. Its bend radius can maintain 1/4~1/2 of G.652 fiber.
According to the standard of compatibility with G.652 fiber, G.657 fiber is divided into Category A and Category B. G657A is fully compatible with G.652D optical fiber,it is used for access network, while G657B is not required to be compatible with G.652D fiber, it is used for short distances at the end of Access networks in bending-rich environments (e.g., buildings).
At the same time, according to the standard of min. Bend radius, G657 is divided into four types of fiber: G657A1 G657A2 G657B2 and G657B3.
Fig. 1: Bend Radius of Single Mode Fiber SMF ITU-T G.652 and ITU-T G.657
G.657B is one type of G657 bend insensitive single mode fiber. The characteristics and application scenarios of G.657B optical fiber are similar to those of G.652D optical fiber. In operation, the optical fiber can be used in D, E, S, C and L5 bands, and it can work in all optical wavelengths from 1260nm to 1625nm. G.657B optical fiber has stronger bending characteristics and more precise geometric specifications and technical standards in order to improve the fiber continuity characteristics in the optical fiber access network.
G.657B fiber work in wavelengths of 1310nm, 1550nm and 1625nm. It is more suitable for and maintains the transmission of FTTH information content, and is installed in rooms or buildings and other narrow places. The application of G657B fiber is only limited to the data signal transmission in the building. Its fusion and connection characteristics are completely different from those of G652, and it can work normally under the condition of very small bending half-diameter.
G657A are fully compliant with ITU-T G.652.D fibres, used in access network, but G657B are fully compatible with ITU-T G.652.D fibres (only small differences in chromatic dispersion and polarization mode dispersion (PMD), which was used in short distance of access network.
| G.657 (2012) | |
| For access networks G.652.D compliant All bands 1260-1625nm |
For end of access networks (e.g., in/near buildings) G.652.D compatible All bands 1260-1625nm |
| A1 Radius min. = 10mm | B2 Radius min. = 7.5mm |
| A2 Radius min. = 7.5mm | B3 Radius min. = 5mm |
Table 1: G657 bend radius
Details like below:
| Features | Unit | G657A1 | G657A2 | G657B2 | G657B3 | ||||||||
| Macro bend diameter | Bend radius | mm | 15 | 10 | 15 | 10 | 7.5 | 15 | 10 | 7.5 | 10 | 7.5 | 5 |
| Number of rolls | – | 10 | 1 | 10 | 1 | 1 | 10 | 1 | 1 | 1 | 1 | 1 | |
| 1550nm max. | dB | 0.25 | 0.75 | 0.03 | 0.1 | 0.5 | 0.03 | 0.1 | 0.1 | 0.03 | 0.08 | 0.15 | |
| 1625nm max. | dB | 1.0 | 1.5 | 0.1 | 0.2 | 1.0 | 0.1 | 0.2 | 0.2 | 0.1 | 0.25 | 0.4 |
Table 2：G.657 Fiber Key Technical Indicators
From above chart, we can know that the mainly difference of both type are the bend radius differs in 3 wavelength 1310nm 1550nm 1625nm, others are the same. For example, operation in 1310nm wavelength, G657A1 minimum bend radius is 10mm, G657A2 minimum bend radius is 7.5mm, which result in G657A2 is more suitable for limited space like corners or ftth mini wall outlet or termination boxes.
From above chart, we can know that the mainly difference of both type are the bend radius differs in 3 wavelength 1310nm 1550nm 1625nm, others are the same. For example, operation in 1310nm wavelength, G657B2 minimum bend radius is 7.5mm, G657B3 minimum bend radius is 5mm, which result in G657B3 is more suitable for limited space.
Answer: G657A optical fiber is bending insensitive single-mode optical fiber 9/125um, fully compatible with G652D optical fiber, mainly used for FTTH optical fiber wiring. However, the biggest difference are the minimum bending radius of G657A1 is 10mm, and that of G657A2 is 7.5mm. This means that the smaller the bending radius is, the better the confined and narrow space is, but the smaller the bending radius is, the higher the cost will be. Therefore, it is the best to choose the proper optical fiber according to the specific construction environment and project budget.
There are many types of optical fiber, which can be divided into single mode fiber and multimode fiber according to the transmission mode. G657 optical fiber is a kind of single-mode optical fiber, Below will analysize single-mode optical fiber G652 and G657.
G652D is one type of G.652 fiber. G652D is the most stringent and completely down-compatible index value of all G652 levels. It has no difference with the general G652 optical fiber in structure, and is the best non-dispersion offset optical fiber for metropolitan area network at this stage.
G.652 fiber is single-mode optical fiber, capable of transmitting 1260~1360nm, 1530~1565nm, and zero dispersion point at 1310nm. G652 can be used in 1550nm optical wavelength to short distance transmission or mutual application with dispersion compensation fiber or control module.
G.652 optical fiber is a kind of single mode fiber widely used on the Internet today. ITU-T divides G.652 into four types of optical fiber, namely G.652A G.652B G.652C G.652D.
G.652A is applicable to 1Gbit/s system software transmission distance of 400km, 10Gbit/s Ethernet interface transmission distance of 40km, and 40Gbit/s system software transmission distance of 2km.
G.652B optical fiber is applicable to 10Gbit/s system software with transmission distance of about 3000km, and 40Gbit/s system software with transmission distance of 80km.
G.652C optical fiber has the same basic characteristics as G.652A, but the transmission coefficient is lower at 1550nm, and the absorption peak of water digestion around 1380nm is cleared, that is, the system software can work in the band of 1360~1530nm.
G.652D characteristics are basically the same as G.652B, and the transmission coefficient is the same as that of G.652C, that is, the system software can work in the 1360~1530nm band.
G657A2 fiber is one type of single mode bend insensitive fiber G.657A series, its bend radius minimum is 7.5mm.
G.657 is the latest member of ITU-T optical fiber series, which is based on the technical requirements of FTTx and its assembly and application. Its bend radius can maintain 1/4~1/2 of G.652 fiber.
According to the standard of compatibility with G.652 fiber, G.657 fiber is divided into Category A and Category B. G657A is fully compatible with G.652D optical fiber,it is used for access network, while G657B is not required to be compatible with G.652D fiber, it is used for short distances at the end of Access networks in bending-rich environments (e.g., buildings).
At the same time, according to the standard of min. Bend radius, G657 is divided into four types of fiber: G657A1 G657A2 G657B2 and G657B3.
Fig. 1: Bend Radius of Single Mode Fiber SMF ITU-T G.652 and ITU-T G.657
G.657B is one type of G657 bend insensitive single mode fiber. The characteristics and application scenarios of G.657B optical fiber are similar to those of G.652D optical fiber. In operation, the optical fiber can be used in D, E, S, C and L5 bands, and it can work in all optical wavelengths from 1260nm to 1625nm. G.657B optical fiber has stronger bending characteristics and more precise geometric specifications and technical standards in order to improve the fiber continuity characteristics in the optical fiber access network.
G.657B fiber work in wavelengths of 1310nm, 1550nm and 1625nm. It is more suitable for and maintains the transmission of FTTH information content, and is installed in rooms or buildings and other narrow places. The application of G657B fiber is only limited to the data signal transmission in the building. Its fusion and connection characteristics are completely different from those of G652, and it can work normally under the condition of very small bending half-diameter.
G657A are fully compliant with ITU-T G.652.D fibres, used in access network, but G657B are fully compatible with ITU-T G.652.D fibres (only small differences in chromatic dispersion and polarization mode dispersion (PMD), which was used in short distance of access network.
| G.657 (2012) | |
| For access networks G.652.D compliant All bands 1260-1625nm |
For end of access networks (e.g., in/near buildings) G.652.D compatible All bands 1260-1625nm |
| A1 Radius min. = 10mm | B2 Radius min. = 7.5mm |
| A2 Radius min. = 7.5mm | B3 Radius min. = 5mm |
Table 1: G657 bend radius
Details like below:
| Features | Unit | G657A1 | G657A2 | G657B2 | G657B3 | ||||||||
| Macro bend diameter | Bend radius | mm | 15 | 10 | 15 | 10 | 7.5 | 15 | 10 | 7.5 | 10 | 7.5 | 5 |
| Number of rolls | – | 10 | 1 | 10 | 1 | 1 | 10 | 1 | 1 | 1 | 1 | 1 | |
| 1550nm max. | dB | 0.25 | 0.75 | 0.03 | 0.1 | 0.5 | 0.03 | 0.1 | 0.1 | 0.03 | 0.08 | 0.15 | |
| 1625nm max. | dB | 1.0 | 1.5 | 0.1 | 0.2 | 1.0 | 0.1 | 0.2 | 0.2 | 0.1 | 0.25 | 0.4 |
Table 2：G.657 Fiber Key Technical Indicators
From above chart, we can know that the mainly difference of both type are the bend radius differs in 3 wavelength 1310nm 1550nm 1625nm, others are the same. For example, operation in 1310nm wavelength, G657A1 minimum bend radius is 10mm, G657A2 minimum bend radius is 7.5mm, which result in G657A2 is more suitable for limited space like corners or ftth mini wall outlet or termination boxes.
From above chart, we can know that the mainly difference of both type are the bend radius differs in 3 wavelength 1310nm 1550nm 1625nm, others are the same. For example, operation in 1310nm wavelength, G657B2 minimum bend radius is 7.5mm, G657B3 minimum bend radius is 5mm, which result in G657B3 is more suitable for limited space.
