高浓度的掺铒光纤在光传输以及光纤相关器件中都发挥着重要的作用。结合改进化学气相沉淀法(MCVD)的特点,采用"在线"溶液掺杂法制备预制棒,并对采用改进的石墨炉加热的MCVD法制备铋镓铝共掺的掺铒石英基光纤预制棒的工艺进行了讨论。特别探讨了疏松层沉积温度的重要性以及铋元素的作用机理,并给出了最佳沉积温度为1560℃-1600℃。利用仪器对制得的光纤进行了测试,给出了光纤的吸收谱、光纤预制棒芯子的扫描电子显微镜(SEM)图像以及用电子探针显微分析仪(EPMA)测得的光纤中各物质的含量,其中在1530 nm处得到的最高吸收系数为近60 dB/m,并利用光纤吸收谱估算得出铒离子浓度约为3.84×10^25m^-3。
High-concentration erbium-doped fiber plays a very important role in optical transmission and related devices based optical-fiber.On the grounds of characteristic of modified MCVD technique,the preforms were manufactured by "online" solution doping technique.The fabrication process of Er^3+-Bi^3+-Ga^3+-Al^3+ codoped fiber by using modified furnace round heating MCVD was discussed.Especially,the depositing temperature of porous core layer was very significant,the best value was 1560 ℃-1600 ℃.The action mechanism of bismuth was also discussed.The effect of increasing concentration of Er3+ by codoped Bi^3+,Ga^3+ and Al^3+ was analyzed.The core areas performances were detected by scanning electron microscope(SEM) and the mole ratio of different ingredients of fabricated fibers were measured by electro-probe micro analyzer(EPMA).The highest absorption coefficient at 1530 nm was about 60 dB/m.The concentration of Er^3+ in the fiber was about 3.84×10^25 m^-3.