Learn three minutes multimode and singlemode fibers distinction
With the development of the network, requires high-rate networks has increased, the optical fiber transmission network as a main medium is more applications among the network cabling. But fiber in the end what difference does it make? I believe there are a lot of people do not know, we now take a detailed look.
Generally, there are two optical fiber: Support multiple transverse mode optical fiber channel or multi-mode fiber is referred to (the MMF), and supports a single mode is referred to as a single mode fiber (SMF).
Single-mode fiber:
in the optical fiber communication, single mode fiber (SMF) is a direct optical signal transmission fiber in landscape mode. Single-mode fiber operating at a data rate of 100M / s or 1 G / s, the transmission distance can be at least 5 km. Typically, single mode optical fiber for remote signal transmission.
Multimode fiber:
fiber communication multimode fiber (MMF) is mainly used for short distance, such as within a building or campus. A typical transmission speed is 100M / s, the transmission distance of up to 2km (100BASE-FX), 1 G / s up to 1000m, 10 G / s up to 550m. There are two types of refractive index: step index and graded index. It supports hundreds of transmission modes, with high bandwidth and low cost.
The difference between single-mode fiber and multimode fiber:
core diameter:
same cladding diameter of single-mode and multi-mode fiber, the diameter is 125 m, but the core diameter of the multimode optical fiber is larger than the diameter of single-mode fiber, typically single mode 9μm, and the multimode fiber is 50-62.5μm.
Transmission distance:
Source:
usually using a laser as a light source and an LED, a laser light source but is more expensive than the LED light source. The laser light source can be controlled accurately, and with high power, single mode fibers typically used. Since the light generated by the LED light sources scattered, typically for multimode fiber.
Bandwidth:
Since the multimode fiber has a larger core size than the single-mode fiber, which supports a plurality of transmission modes. Further, as the same multimode fiber, single-mode optical fibers exhibit modal dispersion caused by a plurality of spatial modes, but the single-mode fiber modal dispersion is less than multimode fiber. For these reasons, single-mode fiber has a higher bandwidth than multimode fiber.
Price:
Since the multi-mode fiber supports a plurality of optical modes, so that its price is higher than the single-mode fiber. However, in the device, a laser diode is much more expensive than the LED, and therefore, the cost of single mode fiber is higher than multimode fiber.
These are the difference between single-mode and multimode fiber, to understand these, to facilitate selection of both. Single-mode fiber for long-distance (or more kilometers) data transmission, applicable to Metropolitan Area Networks, passive optical networks; for short-distance multimode fiber (300 ~ 400m) data transmission, and the like used in the data center room. The budget Alternatively, in single mode fiber and multimode fiber applicable to both scenarios, since the cost of single mode fiber is higher than the cost of multimode fiber, multimode fiber is selected over the others.
TA: Madina
Reprinted: http://www.ie-lab.cn/