The difference and selection of single-mode fiber and multi-mode fiber

With the increasing requirements of communication transmission, optical fiber has become more and more people's first choice for communication laying due to its advantages of fast transmission speed, long distance, safety and stability, anti-interference, and convenient expansion. We often see long-distance data transmission needs in building intelligent projects, basically using optical fiber transmission. However, some users found that there are differences between single-mode fiber and multi-mode fiber in the process of use, so what is the difference between the two, and what kind of occasions are suitable for each, ZR Cable will make a simple answer here.

ZR Cable single-mode fiber and multi-mode fiber

First of all, regardless of single-mode fiber or multi-mode fiber, they are all for long-distance high-quality data transmission. The difference is that the transmission mode of light is different. In single-mode fiber, light propagates along a straight line without reflection. So its transmission distance is very long. The multimode fiber can carry the transmission of multiple optical signals.

A single-mode fiber is an optical fiber with only one (two in most applications) glass fiber, the core diameter is 8.3μm~10μm, and there is only one transmission mode. The bandwidth of single-mode fiber is higher than that of multi-mode fiber, but it has higher requirements on the spectral width and stability of the light source, that is, the spectral width is narrower and the stability is better. The transmission rate of single-mode fiber is higher than that of multi-mode fiber, and the transmission distance is more than 50 times higher than that of multi-mode fiber. Therefore, its price is also higher than that of multi-mode fiber.

Compared with multi-mode fiber, the core diameter of single-mode fiber is much smaller, and the characteristics of small core diameter and single-mode transmission make the optical signal transmitted in single-mode fiber not distorted due to overlapping optical pulses. Among all fiber types, single-mode fiber has the lowest signal attenuation rate and the highest transmission speed.

Multimode fiber is another common fiber type with a core diameter of 50 μm to 100 μm, which can transmit multiple modes at a given operating wavelength. Compared with twisted pair, multimode fiber can support longer transmission distance. In 10mbps and 100mbps Ethernet, multimode fiber can support up to 2000 meters of transmission distance. The core diameters of common multimode fibers are 50 μm, 62.5 μm and 100 μm.

Since there are hundreds of modes transmitted in multimode fiber, the propagation constants and group rates of each mode are different, which makes the bandwidth of the fiber narrow, the dispersion large, and the loss also large. It is only suitable for short-to-medium distance and small-capacity optical fiber communication systems .

In the actual application process, the general transmission distance is long, the single-mode fiber is used, and if the distance is short, the multi-mode fiber is used. The transceiver price of the single-mode fiber is higher than that of the multi-mode fiber.

One of the main ways to distinguish different optical fibers is to look at the diameter of the core and the diameter of the cladding, and industry standards have also been established in the industry. These industry standards play a role in the selection of optical fiber splice connectors and splice tools and splice tools. important role.

If it is an indoor optical fiber, we can also distinguish the indoor single-mode optical cable as yellow, and the indoor multi-mode optical cable as orange.