Comparison Between Single-mode and Multimode Fiber Cables

When searching the Internet for fiber optic cables, the first decision you might encounter is choosing single-mode or multimode. Single-mode fiber cable is a single stand of glass fiber which has a small core diameter that allows transmission of a single ray or mode of light. Multimode fiber cable is made of glass fibers that have a large core diameter designed to carry multiple light rays or mode concurrently, each at a slightly different reflection angle within the optical fiber core. This article will make a comparison between single-mode and multimode fiber cables from the following aspects including core diameter, light source, transmission distance&rate, color code, and application.

Differences Between Single-mode and Multimode Fiber Cables

Core Diameter

The core of all fiber cables carries light to transmit data. The main difference between single-mode and multimode fiber cables is the size of their respective cores. The core diameter of single-mode fiber optic cables is much smaller than that of multimode optical fiber cables. The standard used in broadcasting and production is 9 microns which lowers attenuation and makes the signals travel further. The multimode core diameters, in A/V, are either 50 or 62.5 microns, which makes it possible for more data to pass through the fibers at a given time.

Light Source

Multimode devices usually use a LED as a light source. Because a LED excites a large number of high order modes of optical propagation, and it allows a fiber to be tested across a wide wavelength range. A single-mode device uses a laser, or laser diode to produce light injected into the cable. In addition, the light produced by the lasers is coherent and thin.

Transmission Distance and Rate

Both single-mode and multimode fiber cables can handle 10Gbps speed. Multimode fiber cables generally can reach up to 550 m, while single-mode fiber cables offer a higher transmission distance up to 50 times than multimode fibers, and it has a greater potential that can support runs between 2 m and 10 km or 40 km with ER. Thus multimode fiber cables are mainly applied for shorter distance transmission, while a single-mode cable with lower power loss characteristic is usually used for long distance data transmission.

Color Code

Inside the cable or inside each tube in a loose tube cable, individual fibers will be color coded for identification. When choosing cables, it is easy to distinguish these two types of fiber cables from their colors. Most single-mode cables are color coded yellow, while multimode cables are generally color coded orange or aqua.

Application

Since the single-mode fiber cable uses laser diode as optical transmitters, while multimode fibers use relatively cheaper optical transmitter/receiver, the cost of single-mode fibers is higher than multimode fibers. Due to these features, single-mode fiber cables are usually used for connections over large areas, such as college campuses and cable network. Multimode fiber cables are a good choice for data and audio/visual applications in local area networks and connections within buildings.

Conclusion

Nowadays, single-mode and multimode fiber cables are widely used in fiber optic communication. These two kinds of cables are totally different fiber cables which have their distinctive features. Whether to choose a single-mode or multimode cable depends on your requirement. This article compares single-mode and multimode fibers from several respects. Hope you can get a basic understanding of them.