There are many different frequency bands involved in fiber optic transmission, each with important application value. This article will focus on seven common fiber optic transmission bands and explain their characteristics and uses.
1, 850nm band: Short distance high-speed transmission core
The 850nm band is mainly used for multimode fiber optic systems, suitable for short distance, high bandwidth demand scenarios such as data centers and enterprise LANs. This band is highly matched with gradient refractive index multimode fiber, combined with VCSEL laser, which is both cost-effective and easy to deploy, and widely used in aviation electronics and vehicle optical networks.
2, O-band (1260-1360nm): the ideal band with minimal dispersion
The O-band is one of the earliest bands used in single-mode fiber optic communication, with the advantages of minimal dispersion and moderate loss. It is widely used in urban backbone networks, enterprise dedicated lines, and short distance single-mode communication links.
3, E-band (1360-1460nm): New opportunities brought by "zero water peak" fiber
In the past, the application of E-waves was limited due to the water peak effect (high attenuation caused by water impurities in optical fibers). But with the popularity of "zero water peak fiber", the attenuation of this band has significantly decreased, even better than that of the O-band. At present, it is gradually gaining attention in metropolitan area networks and regional networks that require high spectrum resources.
4, S-band (1460-1530nm): FTTH access core band
The S-band combines low loss and good device response, and is widely used in passive optical network (PON) systems, especially suitable for the 1490nm downstream channel in FTTH. At the same time, it has also become a popular band for the research of next-generation DWDM systems, with the potential to expand the existing bandwidth limit.
5, C-band (1530-1565nm): the backbone of global backbone optical communication
C-band is the preferred band for long-distance communication, submarine cable systems, and large-scale backbone networks due to its lowest attenuation in single-mode optical fibers. It can also be paired with Erbium Doped Fiber Amplifier (EDFA) to achieve efficient amplification and is the standard transmission window for DWDM systems.
6, L-band (1565-1625nm): an important means of expanding capacity on existing networks
Although the L-band has slightly higher attenuation than the C-band, as a natural extension, it can achieve capacity improvement without reconstructing the network architecture. It has good compatibility with EDFA amplifiers and supports rapid deployment of new channels on existing DWDM systems.
7, U-band (1625-1675nm): does not carry business, but is indispensable
Due to significant losses, the U-band is not used for conventional data transmission, but plays a key role in optical cable monitoring. It is used for real-time detection of fiber optic cable loss, reflection, aging and other conditions, and is the basic frequency band for realizing optical network health monitoring. It is often used in conjunction with tools such as OTDR (Optical Time Domain Reflectometer).
