分析了基于偏振光分量强度测量来确定波片参数的方法,指出这类方法在任意波片的测量上存在的不确定性。分析表明,波片相位延迟量与光强测量值之间存在多值函数关系,因而无法仅由线偏振分量光强测量值来确定波片相位延迟量的真正值,包括无法得到波片的级次及快轴方向。提出了把迈克耳孙干涉仪白光干涉的特征性彩虹条纹作为零光程差的定位参考标志,从而可以对光程差进行绝对测量,可以确切测量波片真正的相位延迟量和快轴方向。利用此方法对商用1/4波片进行了测量,实验结果表明所提出的迈克耳孙干涉仪零光程差法是行之有效的。最后还初步分析了色散对测量的影响,讨论了本方法适用的波片范围。

Based on measuring the intensity of components of polarized light, the methods for determining the parameters of a wave plate are discussed and uncertainty of measuring arbitrary wave plate is indicated by the methods. It is concluded that the real phase retardation and fast axis of a wave plate cannot be determined by this kind of methods, because the phase retardation of a wave plate is a multiple valued function of measured light intensity. A method for measuring phase retardation and fast axis of a wave plate using Michelson interferometer is brought forward, in which the rainbow fringe of the Michelson interferometer could be used as an indicator for the zero optical path difference. The method was demonstrated by measuring a commercial quarter-wave plate. The influence of the dispersion of the wave plate material on the measurement is analyzed, and the applicable scope of the method is discussed.