The fixed connection of two optical fibers made with the fusion splicing technique, is also called arc splicing technique or thermal splicing technique. Generally, in this method, two fiber ends are welded together by means of an electric arc.
In fusion splicing, the arc has a temperature of approximately 2,000 degrees Kelvin, thereby bringing the glass to a soft, malleable state. A fusion splicer is required to perform a fusion splice.
Before a splice can be performed, the coating, which consists of primary and secondary coatings, must be removed from the optical fiber. The fiber ends are then cut plane-parallel and axially adjusted for the splice. This alignmentprocess involves three degrees of freedom, takes place under a magnifying lens and is called alignment technology. The actual fusion of the two fibers is achieved by an electric arc generated between two electrodes. To protect the splice, a mechanical splice protector is placed over the fusion splice to protect it from mechanical damage.
The fusion splice is characterized by low attenuation values and has high long-term stability. The guide values for insertion loss should be less than 0.1 dB for multi- mode gradient index fibers and less than 0.05 dB for single-mode fibers.