基于偏振光干涉的一种新型的光纤光栅解调系统

提出一种先进的基于偏振光干涉的光纤光栅解调实现方法 ,偏振光干涉仪也是一种能将布拉格波长移动转化为干涉相位变化的非平衡干涉仪。与传统的非平衡干涉仪不同 ,偏振光干涉仪是利用折射率ne 和no 的差而不是利用光路长短的差来实现非平衡干涉的。另外 ,由于偏振光干涉是发生在有着优良双折射特性的钒酸钇(YVO4)晶体中而不是在石英光纤中 ,这样就可避免石英光纤引入的干涉噪声。通过分析钒酸钇晶体的性质指出 ,利用这种方法来实现光纤光栅温度检测 ,其最小温度测量精度可达± 0 4℃。

A Novel Approach to Fiber Grating Demodulation System Based on the Principle of Polarized-Light Interference

The article introduces an advanced approach to fiber grating wavelength demodulation based on the principle of polarized-light interference. The polarized-light interferometer is also a kind of unbalanced interferometer which can convert the Bragg wavelength shifts into interferometer phase shifts. Different from the conventional unbalance interferometer, this polarization interferometer is based on the unequal refractive index ne and no rather than the unbalanced paths. In addition, the polarized-light interference is generated in the yttrium vanadate (YVO4) crystal with superior birefringence characteristic rather than in the optical fiber by which the interferometer bias is unavoidable. This article points out that through analyzing the properties of YVO4 crystal, ±0.4℃ temperature accuracy can be reached in temperature measurement by this method.