Bare fiber

When procuring bare fiber, you must prioritize geometric and optical consistency. Key specs include cladding diameter (typically 125.0 ± 0.7 μm), core-cladding concentricity error (≤ 0.5 μm), and coating diameter (245 ± 5 μm). For optical performance, verify the attenuation coefficients at 1310nm and 1550nm (standard G.652.D fiber should be ≤ 0.34 dB/km and ≤ 0.20 dB/km respectively) and the zero dispersion wavelength.

Selection depends on the intended use: for long-haul telecommunications, G.652.D (Low Water Peak) is the industry standard due to its versatility. If the fiber is for indoor patch cords or FTTX where tight bends are likely, specify G.657.A1 or A2 (Bend-Insensitive) fiber to minimize signal loss. For high-speed long-distance transmission, G.655 (Non-Zero Dispersion-Shifted) may be required to manage chromatic dispersion.

Suppliers must adhere to ITU-T Recommendations (such as G.652, G.657) and IEC 60793-2 series standards. Ensure the manufacturer holds ISO 9001 for quality management and ISO 14001 for environmental standards. For specific markets like the EU, RoHS and REACH compliance for the acrylate coating materials is essential to avoid customs rejection.

Request a Proof Test level report, which should typically be ≥ 100 kpsi (0.69 GPa) to ensure long-term structural integrity. Additionally, ask for the stress corrosion susceptibility parameter (n-value), which should be > 20 to guarantee the fiber can withstand environmental stress over a 20-25 year lifespan.

The biggest risk is physical damage and micro-bending caused by improper spooling or vibration. Ensure the supplier uses standardized shipping spools (e.g., 25km or 50km lengths) secured in shock-absorbent foam packaging. Always verify that the outer carton is moisture-proof to prevent degradation of the fiber coating during sea freight.

Focus on Total Cost of Ownership (TCO) rather than just the price per kilometer. Negotiate for tiered pricing based on annual volume and request free master-spool samples for lab testing. On Made-in-China.com, prioritize Audited Suppliers and use the platform's Secured Trading Service to protect your payment until the quality inspection report is uploaded.

Always insist on a Pre-Shipment Inspection (PSI) by a third party (like SGS or Intertek) to test attenuation and geometry. Use Letter of Credit (L/C) or Escrow services for first-time large orders. Ensure the contract specifies the Incoterms (e.g., FOB or CIF) clearly and includes a penalty clause for attenuation spikes found upon arrival.

Be aware of Anti-dumping duties (ADD) which some regions (like the EU or India) impose on optical fibers from specific countries. Check your local Harmonized System (HS) Code (typically 9001.10) to determine the exact import tariffs and VAT rates applicable in your country to avoid unexpected costs at the border.