Multimodekuitu

Multimodekuitu, or multimode optical fiber, is an optical fiber designed to carry multiple light propagation modes within a single strand. Its core is relatively large compared with single‑mode fiber, typically about 50 to 62.5 micrometers in diameter, while the cladding is about 125 micrometers. Light is guided by total internal reflection, and because rays take different paths, several modes travel at different speeds, introducing modal dispersion and limiting bandwidth with distance.

There are two common constructions: step‑index multimode fiber, where the core has a uniform refractive index, and graded‑index multimode fiber, in which the index gradually decreases toward the cladding to reduce modal dispersion.

Modern practice groups multimode fibers into categories such as OM1 through OM5, reflecting core properties and bandwidth performance. They typically operate at wavelengths around 850 nanometers for inexpensive transceivers, and at 1300–1550 nanometers for longer links, though compatibility and attenuation vary by type.

Applications include local area networks, data centers, and other premises cabling for short to medium distances. Multimode fiber is generally cheaper to install and enables simpler light sources than single‑mode fiber, but it offers shorter reach due to higher modal dispersion and higher attenuation.

Although single‑mode fiber is predominant for long‑haul networks, multimode fiber remains widely used for cost‑effective, high‑bandwidth short links and is supported by a mature ecosystem of connectors, transceivers, and standards.