Multimode optical fiber is a type of optical fiber that allows multiple light modes to propagate simultaneously. These fibers have a larger core diameter compared to single-mode fibers, which enables them to carry multiple light signals over short to medium distances.

Key characteristics of multimode optical fiber include:

Larger Core Diameter: Multimode fibers typically have core diameters ranging from 50 to 100 micrometers. This larger core diameter allows for easier alignment of light sources and connectors, making them more suitable for use in local area networks (LANs) and shorter-distance communication systems.

Multiple Light Paths: Due to the larger core diameter, multimode fibers can support multiple light paths or modes. Light rays travel through the fiber at different angles, bouncing off the core-cladding interface, which results in different propagation paths and arrival times at the receiver.

Shorter Distances: Multimode fibers are generally used for shorter-distance communication applications, typically within buildings, campuses, or data centers. While they offer high data transmission rates, the signal quality tends to degrade over longer distances due to modal dispersion.

Wavelength Dependent: Multimode fibers are typically optimized for specific wavelengths of light, commonly used with light-emitting diodes (LEDs) or vertical cavity surface emitting lasers (VCSELs). These sources emit light at wavelengths suited for multimode fiber transmission, typically in the range of 850 to 1300 nanometers.

Multimode optical fibers are widely used in various applications, including LANs, data centers, fiber optic networks, and multimedia systems, where high bandwidth and cost-effectiveness for shorter distances are required. However, for longer-distance communication and higher data rates, single-mode fibers are generally preferred due to their lower modal dispersion and higher bandwidth capabilities.