What is required for both mechanical splices and prepolished/splice connectors to achieve low loss?

• A. Field polishing technique
• B. Cleave on the fiber being terminated
• C. Fiber loss
• D. Cable design

Answer: (B)

A clean, flat end-face produced by cleaving is what enables low loss at termination points. When you cleave the fiber being terminated, you create a smooth, planar surface that is perpendicular to the fiber axis. This allows the two fiber ends (in a mechanical splice) or the fiber end and the ferrule/interface (in prepolished/splice connectors) to come into true contact with minimal gaps, micro-roughness, or tilt. The result is less scattering and fewer air gaps, which keeps the light confined and reduces insertion loss and back-reflection.

If the end isn’t properly cleaved, the surface can be angled, rough, or irregular, leading to micro-gaps and scattering that raise loss regardless of the splice type. Field polishing, while used in some setups, is not the universal requirement for achieving low loss. Fiber loss and cable design affect the overall link budget but don’t directly determine the end-face quality at the termination, which is what cleaving directly controls. So, cleaving on the fiber being terminated is the crucial step for achieving low loss in both mechanical splices and prepolished/splice connectors.