为了检测部分偏振光与椭圆偏振光，从复合波片的理论出发，借助于数学工具，对检测方法做了较为详尽的理论分析。结果表明，只要λ／4波片的快(慢)轴与椭圆偏振光的长(短)轴方位一致，则任何椭圆偏振光经过λ／4波片后均可以补偿为线偏振光，而部分偏振光经过λ／4波片后仍为部分偏振光。并搭建了实验光路，测试结果与理论分析完全吻合。

For detecting elliptically polarized light and partially polarized light,the detection method is analyzed frow the view of the composite retardation plate theory. The results indicate any elliptically polarized light can be compensated to become lineally polarized light throught λ/4 wave-plate as long as the fast-axis(slow-axis)of λ/4 wave-plate and the long-axis(short-axis)of elliptically polarized light are in the same orientation,but partially polarized light cann't. Experiments are performanced and the test results accord with theoretical analyses.