Some of the most common single-mode optical fibers include G.652, G.655, G.657, OS1, and OS2, each designed for specific transmission distances and network applications.

ITU-T Standard Single-Mode Fibers

• G.652 (Standard Single-Mode Fiber, SSMF): The most widely used single-mode fiber, featuring a narrow core diameter (~9 µm) that allows light to travel in a single mode, minimizing modal dispersion. It supports wavelengths of 1310 nm (short-haul) and 1550 nm (long-haul with amplification) and is commonly used in long-haul, metropolitan, and FTTH networks .
• G.655 (Non-Zero Dispersion-Shifted Fiber, NZDSF): Designed to reduce dispersion in high-speed, long-distance networks, particularly for dense wavelength division multiplexing (DWDM) systems. It allows higher-speed transmission with less signal loss over extended distances .
• G.657: A bend-insensitive fiber optimized for FTTH and access networks, capable of maintaining performance even in tight bends and indoor installations .

OS1 and OS2 Fiber Types

• OS1: Indoor, tight-buffered single-mode fiber suitable for short-distance applications (up to 10 km). It typically operates at 1310 nm and 1550 nm with a maximum attenuation of 1 dB/km .
• OS2: Outdoor, loose-tube fiber designed for long-distance transmission (up to 200 km). It supports high-speed Ethernet links, including 40G and 100G, with lower attenuation (~0.4 dB/km) and is ideal for outdoor, underground, or aerial deployments .

Key Characteristics

• Core Diameter: Typically 8–10 µm, allowing only a single light mode to propagate.
• Applications: Long-distance telecommunications, data center interconnects, FTTH, cable TV, and high-bandwidth networks.
• Advantages: Minimal modal dispersion, higher bandwidth, and longer transmission distances compared to multimode fibers . These fibers are selected based on network requirements, distance, and environmental conditions, ensuring optimal signal integrity and performance.