研究分析了45°倾斜光纤光栅的工作机理。利用紫外曝光法，将周期为1070 nm 的相位模板旋转一定角度后，在光敏光纤上成功写制了45°倾斜光纤光栅，通过拼接写制技术，写制的光栅栅区长度为24 mm。对写制的45°倾斜光纤光栅的偏振依赖损耗特性进行了研究，在1064 nm 处偏振依赖损耗值为11.8 dB,在1050~1100 nm 范围内的偏振依赖损耗值保持在9 dB 以上。导致其偏振依赖损耗值偏低的主要原因为相位模板的周期不匹配以及光栅栅区长度不够。经过优化后该器件可作为光纤起偏器件使用。

A 45° tilted fiber grating working at 1064 nm is fabricated successfully in photosensitive fiber by ultraviolet (UV) inscription technique. A phase mask with a period of 1070 nm is rotated by 32.7° to the fiber axis to produce tilted fringes of 45° in the fiber core. The length of the 45° tilted fiber grating is about 24 mm. The polarization dependent loss (PDL) characteristics of the tilted grating are experimentally researched. The PDL value of the 45° TFG is about 11.8 dB at 1064 nm and it keeps higher than 9 dB over a wavelength range of 50 nm from 1150 nm to 1110 nm. According to the theoretical analysis, the main causes of the relatively smaller PDL value of the tilted grating are that the period of the phase mask is not the optimum value and the length is not enough.