A joint in which two fibers are aligned in a splicer and welded with an electric arc between two electrodes, leaving a continuous glass path. Typical singlemode loss is 0.02 to 0.05 dB, and many specs set a maximum of 0.1 to 0.15 dB averaged in both directions. The joint has essentially no reflection, and a heat-shrink sleeve shrunk over it protects the bare glass.
Fusion splice loss averaged 0.03 across the whole closure, nothing over 0.08 bidirectional.
Also heard as
- fusion
Do not mix it up with
- Mechanical splice: A mechanical splice clamps the two ends together with index-matching gel, with higher loss and some reflection.
Related terms
Fusion splicer
The instrument that aligns two fiber ends, welds them with an electric arc and estimates the splice loss.
Cleave
To break a stripped fiber in a controlled way so its end is flat, mirror-smooth and square to the axis.
Splice protector
A heat-shrink sleeve with a steel rod that is shrunk over a fusion splice to protect the bare glass.
Mechanical splice
A joint that holds two cleaved fiber ends together in an alignment device with index-matching gel, no arc needed.
Burn
Splicer slang for making fusion splices, from the electric arc that welds the glass.