The difference between single-mode and multi-mode fiber optic cables

Although single-mode fiber optic cable (SMF) and multimode fiber optic cable (MMF) are widely used in various applications, the difference between single-mode fiber optic network cable and multimode fiber optic cable is still confusing.

If you want to know the difference between single-mode and multi-mode fiber, it is better to familiarize yourself with some concepts first. A fiber-based Internet link is a fast and reliable way to transfer data across a network. As mobile devices and computers converge, it is important for businesses to make the best choice between single-mode and multimode fiber optic networks.

The difference between single mode and multimode optical fiber

Single mode optical fiber, single mode or single mode, in terms of its name, has the meaning of the movement of light, this fiber provides the possibility of transmitting one type of light mode along its path, while multimode optical fiber multimode allows the transmission of different modes of light. The difference between single-mode and multi-mode light movement is mainly due to the difference in the diameter of the core of these fibers, which has more characteristics in transmission, including wavelength and light source, bandwidth, supportable distances, and setup costs. .. also affects

The size of the core (core diameter) of optical fibers

Single mode optical fiber has a much smaller core diameter than multimode optical fiber. Normally, the diameter of single-mode optical fiber is expressed as 9 µm, although according to different models of single-mode optical fibers, this diameter varies between 7.6 µm and 10.5 µm (micrometers or microns). Maltese optical fiber also has two sizes: In terms of diameter, which are usually considered 50 µm and 62.5 µm, this larger diameter in multimode optical fibers allows the passage of more modes of light.

Cold Cladding, which actually surrounds the core of the fiber and plays a key role in refracting light and creating refraction in the correct direction of light movement (the refractive index resulting from the difference in the movement of light in the core and cladding or the process of trapping light in the fiber) in the fiber It seems, in both types of multimode and single mode, it has the same diameter and is equal to 125 µm micrometer or micron.

Bandwidth

The bandwidth of multimode optical fiber is limited due to the type of modal or light mode, and the maximum supported bandwidth is currently related to OM5 optical fiber and is 28000MHz MHz * per km, and at the opposite point of the bandwidth in single optical fiber. The mode or single mode is theoretically unlimited and can pass large bandwidth capacity. Bandwidth is an important issue that is also confused with speed today, many people still think that bandwidth is the same as transmission speed, bandwidth is determined based on the capacity of the information transmitted and all the capacities that are announced in the optical fiber network or It is suggested that the transmission capacity or bandwidth is determined based on this. As mentioned, the bandwidth in single-mode optical fiber is unlimited, and therefore the data transfer capacity in single-mode optical fiber is also unlimited.