Complete Guide to Optical Cable Specifications and Models

Fiber optic cables are classified by mode, core size, attenuation, bandwidth, and application, with singlemode (OS1, OS2) for long distances and multimode (OM1–OM5) for shorter, high-speed links.

Fiber Optic Cable Types

Singlemode Fiber (SMF) Singlemode cables have a small core diameter of about 9 microns, allowing only one mode of light to propagate. This minimizes signal dispersion and supports long-distance, high-speed transmission. Common specifications include:

• OS1: Maximum attenuation of 0.4 dB/km at 1310 nm and 0.3 dB/km at 1550 nm, supporting up to 10 km at 10 Gbps .
• OS2: Maximum attenuation of 0.3 dB/km at 1310 nm and 1550 nm, supporting distances up to 40 km at 10 Gbps . Singlemode fibers are typically used in backbone networks, long-haul telecommunications, and high-speed data centers . Multimode Fiber (MMF) Multimode cables have larger cores (50–62.5 microns), allowing multiple light modes. They are suitable for shorter distances and cost-effective installations. Variants include:
• OM1: 62.5-micron core, LED light source, up to 300 meters at 10 Gbps .
• OM2: 50-micron core, LED, suitable for moderate distances.
• OM3/OM4: 50-micron core, laser-optimized for 10G, 40G, and 100G transmission; OM4 supports longer distances than OM3 .
• OM5: Supports Short Wavelength Division Multiplexing (SWDM), transmitting multiple wavelengths over the same fiber for enhanced flexibility .

Cable Constructions

• Simplex: Single fiber, one-way transmission.
• Duplex: Two fibers side-by-side, supporting bi-directional communication.
• Multifiber: Multiple fibers in one cable for high-density applications.
• Patch cords: Short, pre-terminated cables for connecting equipment.
• Bare fiber: Fiber core and cladding only, used for direct connections to light sources .

Key Specifications

• Core and Cladding: Core transmits light; cladding ensures total internal reflection.
• Attenuation: Signal loss per kilometer, measured in dB/km. Lower attenuation allows longer distances.
• Bandwidth: Measured in MHz·km for multimode fibers; higher bandwidth supports faster data rates.
• Jacket Types: Color-coded for fiber type (e.g., orange for OM1/OM2, aqua for OM3/OM4, lime green for OM5) and rated for environmental conditions (plenum, riser, outdoor), .

Connectors and Terminations

Common connectors include LC, SC, ST, MPO/MTP, and CS, chosen based on space, performance, and network design. Pre-terminated solutions like Active Optical Cables (AOC) and Direct Attach Cables (DAC) simplify installation and improve reliability .

Applications

• Singlemode (OS1/OS2): Long-haul networks, metro and backbone links, high-speed data centers.
• Multimode (OM1–OM5): LANs, short-distance interconnects, enterprise networks, and high-density patching.
• OM5 with SWDM: Future-proofing for multi-wavelength, high-bandwidth applications . Understanding these specifications ensures proper cable selection for distance, speed, and environmental requirements, optimizing network performance and longevity.