What are optical fiber splitters made of

Optical fiber splitters are primarily made from quartz or silica glass substrates, optical fibers, and protective coatings, with construction methods varying between FBT and PLC types.

Fused Biconical Taper (FBT) Splitters

FBT splitters are made by fusing and tapering two or more optical fibers together. The fibers' coating layers are removed, and the fibers are stretched under heat to form a double-cone structure. This allows precise control of the light splitting ratio. The main materials include quartz or silica fibers, stainless steel for mechanical support, and gel or epoxy for protection and stability. FBT splitters are cost-effective and suitable for low split ratios like 1×2 or 1×4, but they are sensitive to wavelength variations and temperature changes .

Planar Lightwave Circuit (PLC) Splitters

PLC splitters are fabricated using photolithographic techniques on a silica glass or quartz substrate. Optical waveguides are created on the substrate, often using graded-index silica glass, to route light precisely and achieve uniform splitting. PLC splitters can handle higher split ratios (1×16, 1×32, 1×64) and offer better spectral uniformity and reliability. The materials include silica glass for the substrate, waveguide materials formed via lithography, and protective coatings or enclosures for durability .

Summary

• Substrate: Quartz or silica glass
• Waveguides: Optical fibers (FBT) or lithographically patterned silica (PLC)
• Coatings/Protection: Gel, epoxy, or stainless steel housings
• Construction Method: FBT uses heat and stretching; PLC uses photolithography These materials and methods ensure that optical fiber splitters can efficiently divide light signals while maintaining stability, low loss, and reliability in fiber optic networks .