基于液体选择填充光子晶体光纤的波分解复用器研究

设计了一种基于液体选择填充三芯光子晶体光纤的1.31/1.55um波分解复用器。中间为缺失一个空气孔的普通二氧化硅纤芯，左右两纤芯填充了不同折射率的液体材料。根据光纤的消逝场耦合的模式理论，不对称相邻波导存在波长相关耦合。不同填充折射率的两纤芯与中间纤芯分别耦合，构成两个不同响应波长的光滤波器。通过选择合适光纤长度，可实现不同波长光的分离。采用全矢量有限元法分析了光纤的传输特性，讨论了填充不同折射率液体时波导间的模式耦合，得到了其匹配波长与耦合长度。基于光束传播法仿真发现，长度为4.88 mm的光纤能实现1.31/1.55 um波长光的解复用。

A novel wavelength-division demultiplexer based on selectively liquid-filled photonic crystal fibers

A novel 1.31/1.55um wavelength-division demultiplexer based on selectively liquid-filled three-core photonic crystal fibers (PCFs) is proposed. It consists of a normal central silica core and other two cores selectively filled with different refractive indices of liquid materials. According to coupling mode theory, wavelength-selective coupling of evanescent fields between nonidentical single-mode fibers happens as the propagation constants of two adjacent cores are equal at a particular wavelength. There are two corresponding wavelengths in three-core PCFs and then two beams of light with different wavelength can be separated from each other if appropriate parameters are chosen. Full-vectorial finite element method (FEM) is employed to analyze the properties of PCFs and simulate its coupling wavelength and length with different filled refractive indices. Numerical results by beam propagation method (BPM) demonstrate that it is possible to obtain a 4.88 mm-long 1.31/1.55 um wavelength-division demultiplexer.