What is the difference between single mode fiber and multimode fiber in integrated wiring?

In the case of monitoring the integrated wiring needs to use the fiber, at least we should understand what is the fiber, how to distinguish between single-mode and multi-mode, we try to use the popular text to make it easier for novices to understand. In fact, every professional book has the knowledge of writing fiber, but it seems that there is not much to remember after reading, because it is too professional and too ridiculous for most non-professionals.

Intercept a section to explain the single-mode fiber for everyone to see: "When the geometry of the fiber, mainly the core diameter can be close to the wavelength of light, such as the core diameter D1 in the range of 5 ~ 10μm, the fiber only allows the fundamental mode HE11, in which to propagate The rest of the high-order modes are all cut off. Such fibers are called single-mode fibers."

The above definition is very rigorous, scientific, and can even appear as a point of knowledge in professional examinations.

When you come in through the title of the article, I can go online to extract the definition of the fiber, the definition of the single mode, the definition of the multimode, the characteristics of each, the precautions when using it, you can complete this article, and everyone will read it. Each has its own feelings, most of them are in the clouds, feel that knowledge is still very professional, just blame yourself can not understand ~

But I think that after all, this is not a task. If you can use your own summary to bring you a little bit of nutrients, it is worth the public number to continue to survive.

Optical fiber is a communication line that transmits optical signals. Former Hong Kong Chinese University President Gao Song and a foreign scientist who did not remember the name first proposed that optical fiber transmission communication can be used. For this reason, Gao Song won the 2009 Nobel Prize in Physics.

When used normally, a certain number of optical fibers are combined into a fiber optic cable in a certain way for use in engineering. The core of the fiber is very thin, and it is a glass wire that is almost the thickness of the hair. The cross section is as shown below.

The advantage of the fiber is that it transmits light through the light guide, is non-conductive, and is not afraid of lightning strikes, so it does not need to be grounded.

We are divided into multimode fiber and single mode fiber according to the transmission mode of light in the fiber. For our users, you can remember the multi-mode and single-mode names.

Multimode fiber: Multiple modes of light can be transmitted.

Single mode fiber: Only one mode of light can be transmitted.

The middle core of the multimode fiber is thicker, and the core of the single mode fiber is thinner, but the two are relatively different, the multimode is 50 micrometers, and the single mode is 10 micrometers. If you forget the unit conversion of micrometers, 1 mm = 1000 microns. Multimode fiber transmission distances are relatively close, generally only a few kilometers. Single-mode fiber transmission distances are much farther, usually tens of times that of multimode fiber. Single mode prices are generally more expensive than multimode fiber. The outer sheath line of a single mode fiber is generally yellow in color. The color of the multimode fiber is generally orange-red.

The advantages of using fiber also include:

1. When the transmission distance of the information point is greater than 100m, if you choose to use copper cable. Adding repeaters or adding network equipment and weak rooms can increase the cost and trouble of failure. This problem can be easily solved by using fiber.

2. There are a large number of electromagnetic interference sources in a specific working environment (such as factories, hospitals, air-conditioned computer rooms, electric computer rooms, etc.), and the optical fibers can be protected from electromagnetic interference and operate stably in these environments.

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

4. The environment with high demand for bandwidth has reached more than 1G, and fiber is a good choice.

In the actual application process, if the distance is far away, the single-mode fiber is used; if the distance is close, the multi-mode fiber can be used, and the fiber transmission needs to use the fiber transceiver, the single-mode transceiver for the single-mode fiber, and the corresponding multi-mode fiber. For analog transceivers, single-mode fiber transceivers are more expensive than multimode transceivers.