Which type of fiber optic cable should be used for cold connectors

Single-mode and multimode fiber optic cables with compatible ferrules can support cold connectors such as SC/APC and SC/UPC for field-installable mechanical splicing.

Overview of Cold Connectors

Cold connectors, also known as mechanical splices or fast connectors, allow fiber optic cables to be terminated without a fusion splicer. They use pre-installed index-matching gel or mechanical clamping to align the bare fiber with a short fiber stub inside the connector body, enabling optical signal transmission quickly and cost-effectively . These connectors are ideal for FTTH deployments, emergency repairs, and small-scale installations.

Compatible Connector Types

• SC/APC Cold Connectors: Feature an 8-degree angled endface polish, providing return loss ≥60dB, making them suitable for GPON, EPON, and CATV networks where low back reflection is critical .
• SC/UPC Cold Connectors: Use ultra-physical contact polish with return loss ≥50dB, suitable for general single-mode applications .
• LC Connectors: Miniaturized connectors for high-density applications, also available in cold connector versions for single-mode or multimode fibers .

Fiber Cable Types

Cold connectors can be used with both single-mode and multimode fiber optic cables, including:

• Drop cables for FTTH installations
• Patch cords for distribution boxes and network interconnections
• Specialty fibers designed for extreme environments, including cryogenic or industrial applications, provided the ferrule and assembly materials are compatible with the connector

Environmental Considerations

For extreme cold or cryogenic environments, fiber optic assemblies must be carefully selected. Materials such as acrylate, polyimide, or metal-coated fibers can withstand temperatures down to 1.5 K, but connectors must be designed to prevent crystallization, condensation, or mechanical failure . Standard cold connectors are generally suitable for typical outdoor or indoor installations but may require specialized versions for extreme cold.

Summary

To use cold connectors effectively:

• Choose single-mode or multimode cables compatible with the connector ferrule.
• Use SC/APC for low back reflection applications and SC/UPC for general use.
• Ensure the cable and connector materials are suitable for the installation environment, especially in extreme temperatures.
• Cold connectors provide quick, flexible, and cost-effective termination without fusion splicing, making them ideal for field deployments and emergency repairs .