A multimode optical cable is an optical fiber with a larger core that allows multiple light modes to propagate, typically used for short-distance, high-capacity communication.

Overview

Multimode fiber (MMF) is a type of optical fiber designed for short-distance communication, such as within buildings, campuses, or data centers, where high data rates are required over limited distances . Unlike single-mode fiber, which carries only one light mode, multimode fiber has a larger core diameter, usually 50–62.5 micrometers, allowing multiple light modes to travel simultaneously . This design makes multimode fiber suitable for high-capacity data transmission but limits its maximum distance due to modal dispersion .

Applications

Multimode fiber is commonly used for:

• Intra-building networks and campus connections
• Data centers for high-speed interconnections
• Short-range backbone applications
• Fiber to the desktop or telecom enclosures
• High optical power applications, such as laser welding or spectroscopy equipment

Types of Multimode Fiber

Multimode fibers are classified according to the ISO/IEC 11801 standard into five main types: OM1, OM2, OM3, OM4, and OM5 :

• OM1: Core size 62.5 µm, orange jacket, LED light source, supports 1G Ethernet up to 275 meters and 10G Ethernet up to 33 meters.
• OM2: Core size 50 µm, orange jacket, LED light source, supports 1G Ethernet and 10G Ethernet up to 82 meters.
• OM3: Core size 50 µm, aqua jacket, optimized for laser-based equipment, supports 10G Ethernet up to 300 meters, 40G/100G up to 100 meters.
• OM4: Core size 50 µm, aqua jacket, enhanced for VCSEL lasers, supports 10G Ethernet up to 550 meters, 40G/100G up to 150 meters.
• OM5: Core size 50 µm, lime green jacket, supports short-wavelength division multiplexing (SWDM), optimized for multi-wavelength 40G, 100G, and 400G applications .

Key Characteristics

• Core diameter: 50–62.5 µm
• Light sources: LEDs or VCSEL lasers
• Wavelengths: Typically 850 nm and 1300 nm
• Distance: Up to 550 meters at 10 Gbps, shorter for higher speeds
• Cost: Lower than single-mode fiber due to simpler electronics Multimode fiber is ideal for short-range, high-speed networks where cost efficiency and ease of installation are important, while single-mode fiber is preferred for long-distance communication.