Fabrication and performance investigation of the Nd 3+-doped Heterogeneous helical cladding phosphate glass fiber

Abstract The heterogeneous helical cladding (HHC) fiber is a new type of extreme large mode area fiber proposed by our group firstly. In this work, Nd 3 + -doped phosphate glass HHC fibers with different core radius r ( 60 μ m – 175 μ m ) and different helix pitch Λ (5.25 cm and 10.5 cm) were fabricated successfully. Firstly, the fiber preform glass was designed and prepared, and the performance of which was measured. Secondly, the HHC fiber preform was made by rod-in-tube method. Thirdly, the HHC fiber was obtained by the spiral drawing method, then the loss and gain performance of which were measured. Based on the experiment results, the following conclusions can be drawn: the larger the Λ (or r), the lower the loss coefficient L, and when r (or Λ ) is the same, the larger the Λ (or r), the higher the net gain coefficient. This work will facilitate the further exploration and application of the HHC fiber.