Bismuth‐Doped Multicomponent Optical Fiber Fabricated by Melt‐in‐Tube Method

Bismuth-doped multicomponent optical fiber was fabricated by a melt-in-tube method. The fiber was prepared at drawing temperature where the clad was softened, while the fiber core glass was melted. The obtained fiber was characterized by electroprobe microanalyzer and X-ray diffraction. No obvious precipitation of crystals or bismuth metals was observed in the fiber. Excited by 808-nm laser, intense broadband near-infrared emission with full width at half maximum of about 325 nm was observed from the fiber. Consequently, this fiber is promising for broadband fiber amplification. The melt-in-tube method is generally applicable for fabricating bismuth-doped multicomponent optical fiber.