为了研究微纳光纤的导波和远场辐射特性,采用模式理论和衍射理论分析了微纳光纤芯径与模场、z向能流密度、有效模面积和远场强度的关系,并通过拉锥光纤进行了实验验证。结果表明,通过合理设计,微纳光纤的大部分能量在包层中以倏逝波的形式传输,光纤的有效模面积可以超过1000μm2。拉锥光纤的实验证实了微纳光纤可以有效地传输导波并把其辐射出去。

In order to study guiding and far-field radiation characteristics of micro/nano optical fibers,the relation between core diameters and the mode field,z-direction Poynting vector,effective mode area and far-field intensity was simulated.Then experimental demonstration was carried out by means of tapered fibers.The results showed that the micro/nano fibers might have a large mode area evanescent field larger than 1000μm2 for an appropriate design.Experimental results of tapered fibers verify that the micro/nano optical fiber can effectively guide the field and radiate it out.