Urbanczyk W, Bock W J
Appl Opt. 1994 Jan 1;33(1):124-9. doi: 10.1364/AO.33.000124.
We derived the transfer function for a white-light interferometric sensor based on highly birefringent (HB) fiber, assuming that both sensing and receiving interferometers are dispersive. This transfer function indicates that different responses to changes in the measurand may be observed depending on whether displacement of the contrast function or the interference fringes is detected. In the first case the sensitivity of the sensor is determined by the influence of the measurand on modal polarization dispersion while in the second case it depends on the influence of the measurand on modal birefringence of the HB fiber. This sensitivity difference limits the operation range of recently proposed zero-order fringe-tracking methods within which the unambiguous measurement is possible. The dispersion effects for a white-light interferometric strain sensor composed of York HB or Andrew E-type fiber as a sensing element and a quartz Wollaston prism as a receiving interferometer were studied experimentally. Sensites of modal polarization dispersion, modal birefringence, and chromatic dispersion of modal birefringence to the strain were determined for both types of sensing fiber. For these specific combinations of sensing/receiving interferometers we also determined the unambiguous measurement range for zero-order fringe-tracking techniques.
我们推导了基于高双折射（HB）光纤的白光干涉传感器的传递函数，假设传感干涉仪和接收干涉仪均具有色散特性。该传递函数表明，根据检测的是对比度函数的位移还是干涉条纹的位移，对被测量变化可能会观察到不同的响应。在第一种情况下，传感器的灵敏度由被测量对模态偏振色散的影响决定，而在第二种情况下，它取决于被测量对HB光纤模态双折射的影响。这种灵敏度差异限制了最近提出的零阶条纹跟踪方法的工作范围，在该范围内可以进行明确的测量。对以York HB光纤或Andrew E型光纤作为传感元件、石英沃拉斯顿棱镜作为接收干涉仪组成的白光干涉应变传感器的色散效应进行了实验研究。针对这两种类型的传感光纤，确定了模态偏振色散、模态双折射以及模态双折射的色散对应变的灵敏度。对于这些传感/接收干涉仪的特定组合，我们还确定了零阶条纹跟踪技术的明确测量范围。
