Single Mode Fiber or Multi mode Fiber

Fiber optic cables are now being used in a wider variety of applications than ever before. There are two types of fiber – Single Mode and Multi-Mode. Most people know that single mode fiber is more popular for longer distances while multi-mode is preferred for shorter links, but what is the real difference? We try to shed some light on the technical difference between single and multi-mode fibers.

Let us take a closer look inside a fiber optic cable. Fiber is essentially a hair-thin strand of glass. The core and cladding are usually made of ultra-pure glass.

Fiber Core                                           

It is all in the Mode!

Mode is the path that light travels. Due to the narrow core of the single mode fiber, light travels in a single path through it while in a multi-mode fiber, light travels in many paths.

Dispersion MM

Dispersion SM

In multi-mode fiber, some of the light travels in a direct route while others bounce off the walls. Because of this high dispersion rate, the quality of signal degrades over longer distances.

Cost Equipment cost plays an important role when calculating deployment costs. Single mode fiber requires a light source with narrow spectral width making single mode transceivers and equipment more expensive. Multi-mode fibers typically use low cost light sources like LEDs or VCSELs.

Color Single mode fiber is usually yellow in color. Multi-mode cables come in different types depending on core dia. and bandwidth– OM1, OM2, OM3, OM4 and OM5. OM1 and OM2 fibers are usually orange, OM3 aqua, OM4 aqua or pink and OM5 lime green.

Vitex carries a large array of single mode and multi-mode fiber cables. If you have any questions, call us at 201-296-0145.