Wei Chengli, Menyuk Curtis R, Hu Jonathan
Opt Express. 2016 May 30;24(11):12228-39. doi: 10.1364/OE.24.012228.
We study bend loss in chalcogenide negative curvature fibers with different polarizations, different tube wall thicknesses, and different bend directions relative to the mode polarization. The coupling between the core mode and tube modes induces bend loss peaks in the two non-degenerate modes at the same bend radius. There is as much as a factor of 28 difference between the losses of the two polarization modes. The fiber with a larger tube wall thickness, corresponding to a smaller inner tube diameter, can sustain a smaller bend radius. The bend loss is sensitive to the bend direction when coupling occurs between the core mode and tube modes. A bend loss of 0.2 dB/m at a bend radius of 16 cm, corresponding to 0.2 dB/turn, can be achieved in a chalcogenide negative curvature fiber.
我们研究了硫系化合物负曲率光纤在不同偏振、不同管壁厚度以及相对于模式偏振的不同弯曲方向下的弯曲损耗。纤芯模式与管模式之间的耦合在相同弯曲半径下的两个非简并模式中引发了弯曲损耗峰值。两个偏振模式的损耗相差高达28倍。管壁厚度较大（对应较小的内管直径）的光纤能够承受较小的弯曲半径。当纤芯模式与管模式之间发生耦合时，弯曲损耗对弯曲方向敏感。在硫系化合物负曲率光纤中，弯曲半径为16 cm时可实现0.2 dB/m的弯曲损耗，相当于0.2 dB/圈。
