Single-mode fiber and multimode fiber What is the difference

According to the different transfer point modulus, fiber can be divided into single-mode fiber and multimode fiber. The so-called "model" refers to a certain angular velocity of a beam of light into the fiber. Single-mode fiber using solid-state laser light source, multi-mode fiber light-emitting diode light source is used. Multimode fiber allows multiple beams of light propagation in optical fiber at the same time, creating a model dispersion (because each "mode" of light into the fiber from a different angle they reach the other end of time is different, this feature is called mode dispersion.), mode dispersion limited multimode fiber bandwidth and distance, therefore, multi-mode fiber core wire thick, low transmission speed, the distance is short, the overall transmission performance is poor, but its cost is relatively low, generally used for building or geographical location adjacent environment. Single-mode fiber can only allow a beam of light transmission, so there is no mode single-mode fiber dispersion characteristics, and thus, the corresponding smaller core single-mode fiber, transmission frequency bandwidth, large capacity long distance transmission, but because of their need for laser sources, higher costs.

Multimode fiber

Multi-mode fiber optical signal transmitted through multiple pathways;

usually recommended at a distance of less than a mile applications.Multimode fiber from the transmitter to the receiver's effective range is about 5 miles. Available now from also affected by the transmit / receive unit type and quality of impact; light is stronger, more sensitive receiver, the greater the distance. Studies have shown that the bandwidth of multimode fiber is about 4000Mb / s.

Manufacture of single-mode fiber is to eliminate pulse broadening. As the core size is small (7-9 microns), thus eliminating the light of the jump. In 1310 and 1550nm wavelength using a focused laser source. The direct laser irradiation into the small core, and spread to the receiver, there is no obvious jump. If the multi-mode compared to hunting sad, can also put a lot of bullets loaded barrel, then the rifle is a single-mode, single-light, like a bullet.

Single-mode

fiberSmaller single-mode fiber core, so that light can directly transmit to the center.

Recommended distance is longer used.In addition, single-mode signal from a small loss than multimode. Distance of 3,000 feet in the first, the possible loss of the multimode fiber LED light signal intensity of 50%, while the single-mode losses in the same distance, it has only 6.25% of the laser signal.

Single-mode bandwidth potential to become long-distance high-speed data transmission and the only option. Recent tests show that a single-mode fiber optic cable on the 40G Ethernet can transmit up to 64-channel distance of 2,840 miles.

In security applications, select the multi-mode or single mode of the most common determining factor is distance.If only children miles, preferred multi-mode, because the LED transmitter / receiver needs than the single-mode laser is much cheaper. If the distance is greater than 5 miles, the best single-mode fiber. Another issue to consider is the bandwidth; if future applications may include the transfer of large-bandwidth data signals, the single will be the best choice.