Optical fibers are also divided into single-mode and multi-mode optical fibers? Teach you how to distinguish

Single-mode fiber

The core of single-mode fiber is thin, allowing light to be emitted directly to the center. Recommended for longer distances.

In addition, the distance loss of single-mode signals is smaller than that of multi-mode signals. Multimode fiber may lose 50% of its LED light signal strength over the first 3,000 feet, while singlemode only loses 6.25% of its laser signal over the same distance.

The most common deciding factor in choosing multimode or singlemode in an application is distance. If there are only a few miles, multimode is preferred as the LED transmitter/receiver is much cheaper than the laser required for single mode. If the distance is greater than 5 miles, single-mode fiber is best. Another issue to consider is bandwidth; if future applications are likely to include transmitting large bandwidth data signals, then singlemode will be the best choice.

##Multimode fiber

Multimode fiber propagates light signals through multiple paths; generally recommended for distances less than a mile.

The effective distance of multimode fiber from transmitter to receiver is approximately 5 miles. Available tracking distance is also affected by the type and quality of the transmitter/receiver device; the stronger the light source and the more sensitive the receiver, the greater the distance. Research shows that the bandwidth of multimode fiber is approximately 4000Mb/s.

Single mode fiber is manufactured to eliminate pulse broadening. Because the core size is small (7-9 microns), light hopping is eliminated. Use focused laser sources at 1310 and 1550nm wavelengths. These lasers shine directly into the tiny fiber core and propagate to the receiver without significant jumps. If multi-mode can be compared to a hunting rifle that can load many pellets into the barrel at the same time, then single-mode is a rifle, and a single light is like a bullet.

According to the different modulus of the transmission point, optical fiber can be divided into single-mode optical fiber and multi-mode optical fiber.

The so-called "mode" refers to a beam of light entering the optical fiber at a certain angular velocity.

Single-mode fiber uses solid-state laser as the light source;

Multi-mode fiber uses light-emitting diodes as the light source.

Multi-mode fiber allows multiple beams of light to propagate in the fiber at the same time, thereby forming mode dispersion (because each "mode" light enters the fiber at a different angle and they arrive at the other end point at a different time, this feature is called It is mode dispersion. Mode dispersion technology limits the bandwidth and distance of multi-mode optical fiber. Therefore, multi-mode optical fiber has a thick core, low transmission speed, short distance, and poor overall transmission performance, but its cost is relatively low and is generally used in buildings. Single-mode optical fiber can only allow one beam of light to propagate in an environment or in a geographically adjacent environment, so single-mode optical fiber has no mode dispersion characteristics. Therefore, the core of single-mode optical fiber is correspondingly thinner, and the transmission frequency bandwidth and capacity are large. The transmission distance is long, but the cost is high because it requires a laser source.

Optical cable jacket identification, 50/125, 62.5/125 is multi-mode, and 9/125 (g652) is single-mode. ##The optical fiber can be inspected with a 100/200x magnifying glass after grinding. The small black dot is single-mode, and the larger one with double rings is multi-mode. The fiber core can also be distinguished in the fusion splicer. Look at the center of the fusion splicer monitor. The one that is empty is single-mode, and the one that looks integrated is multi-mode.

Simple usage difference:

Multi-mode is generally used between close places in the park, and the single-mode transmission distance is Far away, it is generally used in the field of telecommunications.

Multi-mode optical fiber is the most primitive technology of optical fiber communication. This technology is a revolutionary breakthrough for mankind to achieve communication through optical fiber for the first time. ##With the development of optical fiber communication technology, especially the development of laser technology and people's urgent need for long-distance and large-scale information communication, people are looking for a better optical fiber communication technology - single-mode optical fiber communication #.

##The digital optical transceiver uses video uncompressed transmission technology to ensure high-quality video signals are transmitted in real time without delay and to ensure high-definition and pure colors of images. This transmission method has a large amount of information data, more than 4 channels. The video optical transceiver uses a data stream of 1.25G bit/s or above, and the 8-channel video data stream is up to 1.5G bit/s

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