高掺锗单模光纤的扩束试验研究

Thermal Expanded Core Experiment of Highly Ge-Doped Single-Mode Optical Fiber

高掺锗单模光纤具有优异的弯曲性能和高非线性性能。由于模场直径和常规G.652光纤失配,两种光纤的连接损耗增加。为了提高模场匹配,采用氢氧焰热处理的方法对高掺锗光纤的纤芯进行扩束。试验结果表明,在热处理初期纤芯扩束不明显;随着热处理时间的增加,热处理120 s后,纤芯扩束速率增加;在热处理后期纤芯扩束速率降低。在热处理4 min后高掺锗单模光纤的纤芯直径接近G.652光纤,这对提升两类光纤的连接性能具有重要意义。

The highly doped germanium single-mode optical fibers have excellent bending resistance and high nonlinearity. Due to the mismatch of the mode field diameter to conventional G.652 fibers, the connection loss increases. To improve mode field matching, H_2-O_2 flame is used to expand the core of highly doped germanium optical fiber. The experiment results show that the expansion of the fiber core is not significant in the initial stage of heat treatment;with the increase of heat treatment time, the rate of fiber core expansion increases after 120 seconds of heat treatment;the expansion rate of the fiber core decreases in the later stage of heat treatment. After 4 minutes of heat treatment, the core diameter of highly doped germanium single-mode optical fiber is close to that of G.652 optical fiber, which is of great significance for improving the connection performance of the two types of fibers.