Multimode Fiber Overview

What Is Multimode Fiber?
Multimode fiber is a kind of optical fiber designed to transport multiple light rays or modes concurrently which are reflected at slightly distinct angles within the optical fiber core. It can typically transmit signals at rates of 10 Mbit/s to 10 Gbit/s over link lengths of up to 600 meters (2000 feet). It is widely used for communication over short distances, such as within a building or on a campus.

What Makes Mutimode Fiber Different
There are various differences between multimode fiber and singlemode fiber. Of all them, the size of the "core" plays the most important role in making multimode fiber distinct from singlemode fiber. Signlemode fiber uses a very thin core which isolates the laser to a single beam, but multimode fiber use a relatively thicker core which allows it to reflect back and forth within the core, having several beams be sent at once. This enables multimode fiber to transmit data at higher rates than singlemode fiber, because the larger core simply can allows more light to be transported simultaneously. It is understood that more light means more data.

What Is Mulimode Fiber Used for？
The equipment used for optical communications over multimode is less expensive than that for singlemode fiber. And due to its other advantages like high capacity and reliablity, multimode fiber is generally used for a backbone. A growing number of users benefits from running fiber to the desktop or to the zone. Standards-compliant architectures such as Centralized Cabling and fiber to the telecom enclosure (FTTE) enable users leverage the distance capabilities of fiber by centralizing electronics in telecommunications rooms, rather than having active electronics on each floor.

Types of Multimode Fiber 
Multimode fiber can be classified into different types by two standards. By their core and cladding diameters, multimode fibers can be divided into two types called step-index fibers and graded-index fibers. The refractive index of graded-index fibers decreases steadily as the distances from fiber axis extends. But the refractive index of step-index fibers decreases dramatically between the core and the cladding. And by the ISO 11801 standard, multimode fibers can be divided into four types called OM1, OM2, OM3, and OM4 which is based on their modal bandwidth. Here is a brief introduction of them.