Multimode Fiber Frequently Asked Questions (FAQ)
How does multimode fiber work?
Multimode fiber continues to evolve, supporting the latest network speeds in enterprise and data center networks. Multimode technology has maintained its ability to provide the most cost-effective short reach links through a combination of fiber and optical component development that takes advantage of technology advances. Fiber bandwidth is a critical component of this equation.
What is multimode fiber used for?
Multimode optical fiber systems continue to be the most cost-effective fiber choice for shorter reach premises, campus, enterprise LAN networks, and data center applications, up to 500 – 600-meter range. This is because multimode optics continues to be less expensive than single-mode optics. Beyond the reach of multimode optical fibers, it becomes necessary to use single-mode optical fiber.
What is the difference between single-mode and multimode fiber?
The way in which these two fiber types transmit light eventually led to their separate names. Generally designed for systems of moderate to long-distance (e.g., metro, access, and long-haul networks), single-mode optical fibers have a small core size (< 10 µm) that permits only one mode or ray of light to be transmitted. This tiny core requires precision alignment to inject light from the transceiver into the core, significantly driving up transceiver costs.
Multimode optical fibers have larger cores that guide many modes simultaneously. The larger core makes it much easier to capture light from a transceiver, allowing source costs to be controlled. Similarly, multimode connectors cost less than single-mode connectors as a result of the more stringent alignment requirements of single-mode optical fiber.
What is the maximum distance for multimode fiber?
Reach of multimode fiber is dependent on the data rate and transceivers used. Industry standards define reaches at given data rates with given transceivers. For example:
• 2 kms at 100 Mb/s (100BASE-FX)
• 1 km at 1 Gb/s (1000BASE-SX)
• 400 – 600 m at 10 Gb/s (10GBASE-S)
• 70 – 150 m at data rates ranging from 40 to 400 Gb/s.
Transceiver manufacturers offer extended reach transceivers to achieve even longer lengths, avoiding the need to use more expensive single-mode optics. In general, multimode optical fiber continues to be the most cost-effective choice for short reach applications.
What is OM3, OM4, and OM5 multimode fiber?
50 µm laser-optimized multimode (OM3, OM4, and OM5) optical fibers offer significant bandwidth and reach advantages for short-reach applications while preserving the low system cost advantages of multimode optical fiber.
Today, 62.5 µm OM1 multimode optical fiber is virtually obsolete and is relegated for use with extensions or repairs of legacy, low bandwidth systems. 62.5 µm OM1 fiber supports only 33 meters at 10G, and is not even recognized as an option for faster speeds.
Why OM5 Wideband?
WideBand OM5 Multimode Fiber is a 50 micron (μm) laser-optimized multimode fiber designed to help meet the demanding requirements of today’s 850 nm based networks, as well as next-generation multimode short wavelength division multiplexing (SWDM) applications. OFS’ LaserWave WideBand OM5 fiber is designed to support light traveling at multiple wavelengths from 850 nm to 953 nm, unlike OM3 and OM4 fibers that are optimized for single wavelength, 850 nm operation.
