Filament Fusion

The cornerstone of all Vytran splicing systems, filament fusion is the most consistent, reliable method for producing high-strength, low-loss splices on the market today.

Features & Benefits

  • Unique filament fusion technologyCreates high-strength, low-loss splices
  • Tunable filament temperatureSplices fibers of many diameters
  • Various filament typesAccommodates broad range of applications – splicing – combiners – couplers – end-caps
  • Fast, repeatable processAllows quick, high-strength splices
  • Fire polishingEnhances splice strength
  • Fire polishingEnables low-loss fusion splices between dissimilar fibers
Our patented filament fusion is a quick, consistent splicing method that preserves a fiber’s inherent strength and properties. The technique uses a heated tungsten or graphite filament to supply the thermal input necessary for fiber fusion. Since the filament’s temperature can be continuously tuned over a wide range, users can splice fibers that range from standard, single-mode fiber to fibers over 1.8 mm in diameter. Different types of filaments accommodate various applications, making the technology versatile enough for splicing large mode area (LMA) fibers, micro-structured fibers and polarization maintaining fibers, for tapering fibers and for creating fiber couplers and fiber beam combining devices. Filament fusion is independent from environment temperature.

Vytran’s patented fire polishing process significantly increases splice strength through a rapid, post-fusion heat treatment of the splice region. When a fusion splice is made, silica evaporate off of the hot center region of the splice and condense on either side of the joint where the fiber is cooler. The condensed silica deposits act as a surface flow, lowering splice strength. Our fire polishing process removes or minimizes the deposits, thereby improving splice strength. In addition, the fire polishing process provides core diffusion capabilities that can be used to adiabatically expand the mode field diameter of a fiber. This thermally expanded core (TEC) process allows extremely low-loss fusion splices between markedly dissimilar fibers.
Fusion Splicer and Fiber Processing Equipment pricing available at