From start to finish, the fusion-splicing process has four main steps: 1. ) preparing the cable and fiber ends, 2. The small mode areas for light propagating through optical fibers lead to high optical intensities even for moderate power levels. It is therefore no surprise that particularly a fiber input end, into which a laser beam is launched, can easily be destroyed, particularly when the fiber end is not. This paper describes the observation of a fiber fuse observed in the core of a high-power high-NA, all-glass, double-clad fiber. Fiber fuse is a phenomenon that results in a specific type of catastrophic destruction of an optical fiber-core from the point of initiation toward the light source. The fibers of different chemical compositions were processed and tested in controlled conditions without. The optical power levels used in optical communication networks have been increasing with the development of long unrepeatered submarine systems, dense wavelength-division-multiplexing (WDM) systems, and distributed Raman amplification systems.
