中文摘要：

特殊光纤维被调查，它在圆柱的 cladding 有一个螺旋状的核心。横梁繁殖方法(BPM ) 被用于在螺旋状核心的纤维的模式损失的性质上分析几何、物理的参数的影响。繁殖损失是为基本模式的 0.32 dB/m ，当核心直径是 19 m 时，繁殖损失是为在 10501065 nm 的波长范围的 LP11 模式的 20.95 dB/m ，核心螺旋的沥青是 2.66 公里，并且从纤维轴的中心的螺旋核心的偏移量是 31 m 。单个模式的螺旋状核心的纤维的核心直径很好超过常规 large-mode-area 纤维的。螺旋状核心的纤维能提供有效 large-mode-area 没有卷纤维或选择刺激的单个模式的操作模式。

英文摘要：

A special optical fiber is investigated, which has a helical core in the cylindrical cladding. The beam propagation method （BPM） is used for analyzing the impacts of the geometric and physical parameters on the properties of mode losses of the helical-core fiber. The propagation loss is 0.32 dB/m for the fundamental mode and the propagation loss is 20.95 dB/m for the LPu mode in the wavelength range of 1050-1065 nm when the core diameter is 19 μm, the pitch of the core＇s helix is 2.66 mm, and the offset of the helix core from the center of the fiber axis is 31 μm. The core diameter of the single-mode helical-core fiber well exceeds that of the conventional large-mode-area fiber. The helical-core fiber can provide the effec- tive large-mode-area single-mode operation without coiling fiber or selecting excitation mode.