We present a novel polarization alignment technique based on windowed Fourier-transform (WFT) spectral interferometry to determine the wavelength-dependent orientation of the principal polarization axes of photonic crystal fibers (PCFs). To test the technique, a commercially available, 82.5-cm-long HC-800-02 type hollow-core PCF was measured. The angles belonging to the fast and the slow principal axes of the fiber were determined from the peak intensity values of the ridges in the WFT map at different wavelengths. We demonstrate that the orientation of the principal polarization axes of the tested PCF is wavelength-dependent. The precision of the angle measurement was better than 0.3°.

中文翻译：

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通过窗口傅里叶变换光谱干涉法测量的光子晶体光纤主轴的波长依赖性取向。

我们提出了一种基于开窗傅立叶变换（WFT）光谱干涉法的新颖的偏振对准技术，以确定光子晶体光纤（PCFs）的主偏振轴的波长相关方向。为了测试该技术，测量了市售的82.5厘米长的HC-800-02型空心PCF。根据在不同波长的WFT图中的脊的峰值强度值确定属于光纤的快主轴和慢主轴的角度。我们证明了被测PCF的主要偏振轴的方向与波长有关。角度测量的精度优于0.3°。