According to the ITU standard, there are seven types of optical fiber: G651, G652, G653, G654, G655, G656, G657.Let’s get to know it together and don’t get lost in the work.
Multimode Fiber
G.651 fiber (multimode gradient refractive index fiber)
- Suitable for wavelengths of 850nm/1310nm.
- Mainly used in local area networks, not suitable for long distance transmission
Single-mode Fiber
G.652 (dispersion non-shifted single-mode fiber)
- Zero-dispersion wavelength of about 1310 nm, but can also be used in the 1550 nm wavelength range.
- Optical fibers are limited in the direction of coherent transmission due to their transmission loss and nonlinear characteristics.
- The most widely used optical fiber
G.653 (dispersion-shifted fiber)
- Dispersion is minimized around 550nm wavelength, thus minimizing optical loss.
- Due to the four-wave mixing caused by the DWDM system channel nonlinear interference is very serious, low power into the fiber, is not conducive to more than 2.5G multi-channel WDM transmission.
- Ideal for long-distance single-channel optical communication systems.
G.654 (cutoff wavelength shifted fiber)
- Lowest attenuation coefficient at 1550nm (about 15% lower than G652, 6653, G655 fibers), so it is called low attenuation fiber, dispersion coefficient is the same as G652.
- Due to the high-order mode of the multi-optical interference on the system transmission will have a greater impact, and at the same time it can not meet the requirements of the future expansion of transmission to the S, E, O-band.
- Mainly used in submarine or terrestrial long-distance transmission
G.655 (Non-Zero Dispersion Shifted Fiber)
- 1550nm dispersion is close to zero, but not zero.
- Due to the small dispersion of the fiber, the effective cross-sectional area is small, resulting in a strong nonlinear effect, the transmission distance is only 60% of G.652.
- Early used in WDM and long distance fiber optic cable
G.656 (Low Slope Non-Zero Dispersion Shifted Fiber)
- Attenuation is low at 1450nm -1625nm, but dispersion is too low for WDM systems when wavelength is less than 1530nm
- Ensures transmission performance over a wider wavelength range in DWDM systems.
G.657 (bend-resistant optical fiber)
- Bend loss insensitive fiber with minimum bend radius
- The most commonly used fiber optic cable for FTTH to the home
The above seven is my summary of the knowledge about optical fiber, of course, the technology is iterating, such as the future will be launched hollow core fiber, SDM fiber, etc. pay attention to me, continue to take you into the world of fiber optic communications.
