Optical fiber is a bundle of glass or plastic that can transmit light over long distances, which is similar to cables used to carry electricity. Optical fiber is widely used in telecommunications, medical applications, sensing, data communications, and other fields. In fact, there are two types of transmission modes of optical fiber. They are single-mode fiber and multi-mode fiber.
What is single-mode fiber?
Single-mode fiber is designed with a small core diameter, offering a single pathway for light to travel. It only propagates along a straight line and has no reflection, which makes the transmission bandwidth higher, so it is suitable for large-capacity, long-distance systems.
What is multi-mode fiber?
Multi-mode fiber can support the transmission of multiple optical signals. That can easily cause a large dispersion. And the bandwidth is lower because of the dispersion. Multi-mode fiber can bear harsh environments and transmit a large number of data in a short distance, which makes it suitable for industrial and medical communications.
Differences between single-mode fiber and multi-mode fiber
Both single-mode fiber and multi-mode fiber can transmit data or information. However, they have differences in physical structure and effects.
1. The core diameters are different.
Both the cladding diameters are 125μm. However, the core diameter of the multi-mode fiber is larger than that of the single-mode fiber.
| Optical Fiber | Cladding Diameters | Core Diameters |
|---|---|---|
| Single-mode Fiber | 125μm | 9μm |
| Multi-mode Fiber | 125μm | 50μm/62.5μm |
2. Appearance of different colors.
Sheathed colors can be used to distinguish the types of optical fibers. The single-mode fibers use yellow sheathes and the multi-mode fibers can have different colors based on the types of the fibers. For example, multi-mode fiber OM3 uses blue, and OM5 uses green.
3. The operating wavelengths are different.
Single-mode fibers typically operate in the 1310nm and 1550nm bands, while multimode fibers operate in the 850nm bands.
4. Attenuation and dispersion are different.
Single-mode fiber has low attenuation, small dispersion, low signal loss in the transmission process, and is not easy to distort. However, multi-mode fibers have relatively high attenuation and severe dispersion, limiting their transmission distances.
5. The transmission distance is different.
The single-mode fiber is suitable for long-distance transmission, the distance is generally from 1 km to 120 km. But the multi-mode fiber can only support short-distance transmission, the distance is shorter than 1 km.
Optical Fiber in KVM Extenders
Optical fiber plays an important role in KVM extenders. A KVM extender consists of a transmitter for sending signals and a receiver for accepting signals. The function of KVM extenders is to extend the transmission distance. That is why KVM extenders are designed with optical fiber ports. For example, Kinan KVM fiber extenders are designed with SFP+ ports to connect optical fiber modules that can achieve photoelectric and electro-optical conversion. As for Kinan fiber extenders, the transmission distance of single-mode fiber is up to 10km, and that of the multi-mode one is 300m. Choosing which mode depends on the need for transmission quality and transmission distance.
Conclusion
Optical fiber is important for telecommunications because of its fast speed and low loss. Multi-mode fiber is more suitable for harsh environments and supports shorter transmission distances than single-mode fiber. In KVM extenders, the fiber cables can be connected to optical fiber modules to achieve the conversion of optical signals to electrical signals and long-distance transmission.
