Understanding Singlemode and Multimode Fiber Optic Cables

Fiber optic cables are generally divided into two types: single mode and multi-mode. Understanding characteristics of each fiber types help understand the applications for which they are used. Earlier in 1970, fiber optic cables are researched to have the capabilities of carrying 65,000 times more information then just regular copper wire, through with information carried by a pattern of light waves that could be detected at a distance of even 1000 miles away.

Real life uses of fiber optics
There are two basic types of fiber optic cables: multi-mode and single mode fiber. Multimode fiber is best designed for short transmission distances, and is suitable for use in LAN systems and video surveillance. Single-mode fiber is best designed for longer transmission distances, making it suitable for long-distance telephony and multichannel television broadcast systems. Fiber optics is very important in communications, because it can be used to transmit information very efficiently. Fiber optics also have visual users. Fiber optics is used in medicine to look inside the body. By using optical fiber cables, doctors can examine organs and diagnose illness without surgury or X-rays. Optical fibers can also deliver laser light to specific points in side the body to help surgons with delicate surgery. A local radia station uses fiber optical cables instead of FM waves.

Multimode and Singlemode Fiber
Multimode fiber is the first to be manufactured and commercialized, simply refers to the fact that numerous modes or light rays are carried simultaneously through the waveguide. Modes result from the fact that light will only propagate in the fiber core at discrete angle within the cone of acceptance. This fiber type has a much large core diameter, compared to single-mode fiber, allowing for the larger number of modes, and multimode fiber is easier to couple than single-mode optical fiber. Multimode fiber may be categorized as step-index or graded-index fiber. Multimode Step-index Fiber core’s index of refraction is higher than the cladding’s index of refraction, the light that enters at less than the critical angle is guided along the fiber. Multimode graded-index fiber core’s refractive index is parabolic, being higher at the center. They follow a serpentine path being gradually bent back toward the center by the continuously declining refractive index.

Single-mode fiber allows for a higher capacity to transmit information because it can retain the fidelity of each light pulse over longer distances, and it exhibits no dispersion caused by multiple modes. Single-mode fiber also enjoys lower fiber attenuation than multimode fiber. Thus, more information can be transmitted per unit of time. Like multimode fiber, early single-mode fiber was generally characterized as step-index fiber meaning the refractive index of the fiber core is a step above that of the cladding rather than graduated as it is in graded-index fiber. Modern single-mode fibers have evolved into more complex designs such as matched clad, depressed clad and other exotic structures.

A interesting fact is that an optical fiber cable is less than 1/2 inch in diameter, which could carry more than 40,000 telephone conversations at once. Today more than 80% of the worlds long-distance traffic is carried over optical fiber cables.Additional important variety of multimode and single mode fiber includes polarization-maintaining, Low smoke zero halogen, armored fiber.

This article is source from fibre optic cable manufacturers.