Parameter Table for Ordinary Optical Cables

Ordinary optical cables are characterized by their core and cladding dimensions, attenuation, dispersion, bandwidth, and transmission wavelength, which together determine their performance in data transmission.

Geometric Parameters

• Core Diameter: Single-mode fibers typically have a core of about 8–10 microns, while multimode fibers range from 50 to 62.5 microns .
• Cladding Diameter: Standard cladding is usually 125 microns for both single-mode and multimode fibers .
• Coating/Buffer: Protective polymer layers around the cladding, often 250 or 900 microns, provide mechanical protection .
• Mode Field Diameter (MFD): For single-mode fibers, MFD measures the transverse extent of the light field, typically around 9 microns at 1310 nm .

Optical Parameters

• Attenuation (Loss Coefficient): Measures power loss per kilometer, expressed in dB/km. Typical values are ≤0.18 dB/km for low-loss single-mode fibers at 1550 nm, and 0.4 dB/km at 1310 nm for standard OS1 fibers .
• Dispersion: Includes chromatic dispersion (pulse spreading due to wavelength dependence) and modal dispersion (in multimode fibers). Single-mode fibers like G.652 have chromatic dispersion around 17 ps/nm·km at 1550 nm .
• Numerical Aperture (NA): Determines light acceptance angle; typical multimode fibers have NA ≈ 0.2–0.3 .

Transmission Characteristics

• Bandwidth: Multimode fibers are rated in MHz·km (e.g., 200 MHz·km at 1310 nm for OS1), while single-mode fibers support very high bandwidth over long distances .
• Operating Wavelengths: Common wavelengths are 850 nm and 1300 nm for multimode, and 1310 nm and 1550 nm for single-mode fibers .
• Maximum Transmission Distance: Determined by attenuation and system sensitivity; low-loss single-mode fibers can transmit over 100 km without amplification .

Additional Considerations

• Absorption Losses: Caused by impurities (OH⁻ ions, metal ions) and intrinsic SiO₂ vibrations .
• Mechanical and Environmental Protection: Optical cables include jackets and armoring to resist bending, temperature changes, and moisture .
• Standards Compliance: ITU-T and IEC standards (e.g., G.652, IEC 60793) define fiber characteristics, test methods, and acceptance criteria for consistent performance . These parameters collectively determine the suitability of an optical cable for specific applications such as FTTH, 5G backhaul, or long-haul telecommunications, ensuring reliable high-speed data transmission.