大模场面积掺镱双包层光纤研究

Large Mode Area Yb^(3+)-doped Double-clad Optical Fibers

采用改进的化学汽相沉积工艺,沉积了光纤阻挡层和疏松层.结合溶液掺杂技术,研究了疏松层沉积温度、镱铝共掺工艺条件对掺镱浓度的影响,研究了大模场面积纤芯的制备工艺,实现了高浓度大模场面积掺镱双包层光纤的研制.测量并分析了光纤的光学性能参数及其激光特性,光纤芯径达到30μm,纤芯s镱浓度提高到4000ppm以上,芯数值孔径降至0.07,光纤的模场面积从113μm2提高到1256μm2,光纤的非线性效应阈值功率由12W提高到大于128W.

With the MCVD（Modified Chemical Vapor Deposition） manufacture technics, the fiber isolation layers and porous frits were deposited. Under the condition of solution-doping, the effect of the technics. such as the temperature of porous frits,and Yb-Al codoping, were investigated. The core fabrication of the large mode area fiber was studied. The high concentration large mode area Yb-doped double clad fiber was obtained. The fiber optical parameters and laser characteristic were measured and analysed. The fiber core diameter is 30μm. The concentration of Yb-ions is up to 4 000 ppm and the core NA is 0.07. The increase of mode area from 113 μm^2 to 1 256 μm^2 .and the nonlinear threshold from 12 W to 128 W are realized.