新型1×N多模干涉分束器的三维设计与模拟

相比于传统的1×N对称型多模干涉（Mult-Mode Interference,MMI）分束器设计,提出了一种新型埋入式弱限制光波导分束器件.它的干涉区及输入输出波导采用倒锥形式,器件尺寸减小,且不均匀性与附加损耗也减小.以1×4的对称型MMI分束器为例,当只对干涉区采用倒锥形结构后,在TE偏振中心波长为1.55 μm时,器件长度减小了500 μm,均匀性增加了0.131 dB,而附加损耗仅增加了0.02 dB,波长响应较传统设计增加了40 nm.在此基础上,又在输入输出臂上也各增加倒锥形结构后,相比于传统设计附加损耗减小了0.02 dB,均匀性增加了0.139 dB,器件长度减小了500 μm.改进后的器件具有优越的容差性.器件采用掺氟型聚合物材料进行优化设计,通过在合理范围内偏离输出波导位置,使输出光强达到最大值.

3-D Design and Simulation of a New Type of 1 × N MMI Power Splitter

A new type of buried polymer 1×N multimode interference (MMI) power splitter is presented. Compared to the traditional design of MMI, interference region of the MMI power splitter takes the shape of reverse taper. The dimension of the splitter is reduced, the uniformity is also enhanced, and the excess loss and crosstalk is retained in a good level. Taking a 1×4 symmetric MMI splitter as a example, the length of the splitter is diminished in 500 μm than the traditional one, the uniform is increased in 0.131 dB,the excess loss is decreased in 0.02 dB, and wavelength response is increased in 40 μm. The MMI also own super tolerance. The polymer splitter by moving output away from the central position is optimized, and the maximal output power is in maximal value.