What is the difference between single-mode fiber and multi-mode fiber?

Monitor the integrated wiring needs to use optical fiber, at least we should understand what is optical fiber, single mode multi-mode how to distinguish, our article to try to use popular text to let beginners understand. In fact, every professional book has the knowledge of writing optical fiber, but it does not seem to remember much, because for most non-professional people are still too professional and too rare.

Take an explanation of the single mode fiber to see: " When the geometric size of the optical fiber, mainly the core diameter can be similar to the light wavelength, such as the core diameter D1 in the range of 5~10 µ m, the optical fiber only allows the base mode HE11, in which propagation, the rest of the high mode all cut off, such fiber is called single mode fiber.”

Optical fiber is a kind of communication line transmitted by optical signals. For the first time, the former president of Charles Kao, the Chinese University of Hong Kong, and a foreign scientist who could not remember the name won the 2009 Nobel Prize in Physics.

Usually used, a certain number of optical fiber combined in a certain way for use in the project. The fiber of the fiber is very thin, is a kind of glass about the thickness of a hair.

The advantage of optical fiber is that it transmits signals through conducting light, does not conduct electricity, and is not afraid of lightning strikes, so it does not need to use grounding protection.

According to the transmission mode of light in optical fiber, we are divided into multi-mode fiber and single-mode fiber. For us users, you can remember the origin of the multi-mode and single-mode names.

Multi-mode fiber: It can transmit light in multiple modes.

Single-mode fiber: It can transmit only one mode of light.

The multi-mode fiber core wire is thicker, the single mode fiber core wire is thin, only two relative, the multi-mode is 50 microns, the single mode is 10 microns. If you forget the unit conversion of the micron, 1 mm =1000 micron. Multi-mode optical fiber transmission distance is relatively close, generally only a few kilometers. The transmission distance of single mode fiber is far farther, usually can reach dozens of times that of multi-mode fiber. Single mode price is generally more expensive than multi-mode optical fiber price. The color of single mode optical fiber is generally yellow. The color of the multi-mode fiber is usually orange.

The advantages of using optical fiber also include:

1. If the transmission distance of the information point is greater than 100m, if you choose to use the copper cable. You have to add repeaters or add network equipment and weak currents, thereby increasing costs and potential failure problems, which can be easily solved by using optical fibers.

2. In the specific working environment (such as factories, hospitals, air conditioning rooms, power room, etc.), there are a large number of electromagnetic interference sources, optical fiber can be free from electromagnetic interference, stable operation in these environments.

3. There is no electromagnetic leakage of the optical fiber, so it is very difficult to detect the signal transmitted in the optical fiber. It is a good choice in places where the confidentiality levels are high (such as military, research and development, audit, government, etc.).

4. In the environment with high bandwidth demand, reaching above 1G, optical fiber is a good choice.

In the practical application process, if the distance is far, use single-mode optical fiber; if the distance is near, you can use multi-mode optical fiber, use the optical fiber transceiver, single-mode transceiver, the transceiver price is higher than the multi-mode transceiver.