What is single-mode fiber optic

In fiber optic communication, single-mode fiber is a type of fiber designed to transmit a single beam (mode) of light. Usually, there are multiple wavelengths of light within this beam. Although the beam propagation path is parallel to the fiber optic cable, it is commonly referred to as the transverse mode because its electromagnetic wave oscillation direction is perpendicular to the fiber optic cable.

Single mode fiber does not disperse like multimode fiber, and single-mode fiber does not disperse. Single mode fiber is also better than multimode fiber in maintaining the accuracy of long-distance optical pulses. So the bandwidth of single-mode fiber is higher than that of multi-mode fiber. Single mode typically uses lasers as light sources, while multimode typically uses light-emitting diodes as light sources. Single mode related equipment is also relatively expensive, but single-mode fiber itself is cheaper than multimode fiber.

A typical fiber core diameter is between 8 and 10 µ m, while the diameter of the coated fiber shell is 125 µ m; The wavelength of light that can pass through is 1310 or 1550 nm. Single mode optical fibers can be made into various special specifications based on their different physical or chemical properties, such as non-zero dispersion optical fibers and zero dispersion optical fibers. Single mode optical fibers are typically coated in yellow to distinguish them from multi-mode fibers coated in orange.