Economical choice: Optical Fiber and optical fiber cabling principles

Optical fiber is short for optical fiber. It consists of a fine glass wire with a diameter of about 1mm. It is transparent and slim. Although it is fine than the hair, it has a guided wave structure that closes the light in it and transmits along the axial direction. Optical Fiber Communication is a kind of communication method that develops with the magic structure of optical fiber as the carrier frequency and optical fiber as the transmission medium.

Currently, optical communication uses a wavelength range of 0.8 to 1.8um in the near-infrared zone. Can be divided into short wave length 0.85um) and long wavelength segments 1.31um and 1.55um ). As optical fiber communication has a series of excellent features, optical fiber communication technology has developed rapidly in recent years. It can be said that this emerging technology is an important symbol of the world's new technological revolution, and is also the main transmission tool of various information networks in the future information society.

In summary, optical fiber communication has the following advantages:

Transmission frequency bandwidth, communication capacity, large optical fiber network,

According to information theory, the higher the carrier frequency, the larger the communication capacity. Currently, the optical frequency is 1000 to 10000 times higher than the microwave frequency, and the communication capacity can be increased by 1000 to 10000 times.

Currently, all optical fiber cables of the Z series are used. Because the purity of the silica glass media is extremely high, the loss of the optical fiber is extremely low, and the relay distance can be very long. In this way, the number of relay stations can be reduced in the communication line to reduce the cost and improve the communication quality.

Optical fiber network without electromagnetic interference

Because optical fiber is a non-metallic medium material, it is naturally not subject to electromagnetic interference. This is beyond the reach of other cables.
 
Wire Diameter, fine weight, light optical fiber network

Because the diameter of the optical fiber is only about 1mm, the finished optical fiber cable is thinner than the metal cable and lighter, which facilitates the manufacture of multi-core optical fiber cables and improves the space utilization rate of the cables.

Resource-rich Optical Network

The main component of the optical fiber is Z. Therefore, the material resources of the optical fiber are abundant and the manufacturing cost is low. It is favored by this unique advantage alone.

Because of the above advantages of optical fiber, the broadband Fiber gradually replaces the metal cable in the narrow band since 1980s.

However, it is impossible for a thing to be completely perfect, and the optical fiber itself has its own shortcomings. For example, if the texture is brittle and the mechanical strength is low, it is its critical weakness. If you do not pay attention to it, it will be broken into the outer skin of the optical cable. The construction personnel should have good cutting, connection, division and coupling technologies. However, with the continuous development of technology, these problems can be overcome.

In a structured cabling system, optical fiber not only supports FDDI trunk, 1000Base-FX trunk, 100Base-FX to desktop, ATM trunk to desktop, but also supports CATV/CCTV and optical fiber to desktop FTTD ), therefore, it and copper cables become the leading role in structured cabling.

Today, there are two mainstream wiring standards, one is standard EIA/TIA-568A in North America and the other is the international standard ISO/iecis11801. EIA/TIA-568A and ISO/IECIS11801 the 62.5/125um multimode optical fiber, 50/125 um multimode optical fiber, and 8.3/125um multimode optical fiber are recommended.

Single-Mode Optical Fiber and multi-mode optical fiber can be easily determined by the size of the core.

The core of a single-mode optical fiber is very small, about 4-10 um, and only the main mode is transmitted. This completely avoids modal dispersion, so that the transmission frequency band is wide and the transmission capacity is large. This type of optical fiber is suitable for large-capacity, long-distance optical fiber communication. It is an inevitable trend in the future development of optical fiber communication and light wave technology.

Multimode Optical Fiber is also divided into multimode mutant optical fiber and multimode gradient optical fiber. The former has a large diameter and many transmission modes, so the bandwidth is narrow and the transmission capacity is small. The refractive index in the latter decreases with the increase of the radius, and a relatively small modal dispersion can be obtained, therefore, the bandwidth is wider and the transmission capacity is large. We generally apply the latter. Optical Network,

Dimensions of the core and outer skin of common multimode and Single-Mode Optical Fiber: Multimode Optical Fiber Core/outer skin ):

50/125 um

62.5/125um

Single-Mode Optical Fiber Core/outer skin ):

8.3/125um

800nm-900nm

Short Wave Band

1250nm-1350nm

Long Wave Band

1500nm-1600nm

Long Wave Band

In these bands, the optical fiber transmission performance is optimal, especially in the center wavelength of the band. Therefore, the operating wavelength of multi-mode optical fiber is 850nm or 1300nm, while that of single-mode optical fiber is 1310nm or 1550nm.

However, no matter what the optical fiber transmission performance is, it still has to face the biggest problem in the communication system-signal attenuation. In optical fiber cabling, there are internal external causes of attenuation. The internal attenuation is related to the optical fiber material, while the external attenuation is related to the construction and installation. The reduction of internal attenuation depends on the cable manufacturer. They will focus on improving materials and processes. External attenuation is generally caused by time-varying fiber laying, coupling loss between optical fiber and light source, and connection loss between optical fiber. These can be reduced through the efforts of the construction personnel. Therefore, during construction, the construction personnel should note:

Optical Network

1) The bending radius cannot exceed the minimum.

2) The traction of laying optical cables should not exceed the maximum laying tension. At the same time, external force lateral pressure, impact, bending, and distortion of the optical fiber should be avoided ).

3) strictly trained technicians should perform optical fiber connection and maintenance.

When the optical fiber trunk is used, each floor must use at least 6-core optical fiber cables. It is best to use 12-core optical fiber cables for advanced applications. This is from three aspects: application, backup, and expansion. The optical fiber networking mode is also flexible. You can:

1. Point-to-point. Establish express connect between two computers. The transmission rate is several Mbps to several hundred Mbps, and the distance is 2 km, multi-mode) to 5 km single-mode ).

2. Star network. A star network topology is created using optical fiber network devices.

3. Ring Network. The optical fiber connects the signal generator to form a loop.

With the development of science and technology, the requirements for optical fiber are higher and newer. The old Cabling Standards have been tested in practice and are being revised. In addition to revising the original specifications, new requirements will also be added. We believe that optical fiber will play a more important role in this process. It is not difficult to predict the bright future of optical fiber communication and optical fiber cabling.

1. New Medium creates a high-performance optical fiber cabling Solution
2. Optical Fiber Communication: Application of switching technology in Optical Networks