径向偏振光纯度检测及偏振态分布特性评价

光束横截面内偏振态分布均匀性是影响径向偏振光光束质量及其实际应用的关键因素。通过PBS测量法、狭缝法和S波片法三种方法对径向偏振光偏振纯度进行测量和对比，分析了径向偏振光偏振态在横截面内分布均匀性。在PBS测量法和狭缝法测量径向偏振光过程中，给出了径向偏振光纯度表达式，分别测得径向偏振光纯度为93.4%和84.1%，并引入方差公式评价径向偏振光偏振态分布均匀特性。其中PBS测量法表达径向偏振光纯度更为准确，狭缝法可以通过比较不同区域偏振度更精确地反映径向偏振光偏振态分布特性。S波片法可以使用市场现有偏振分析仪间接测量径向偏振光纯度，更适应于测量径向偏振光在放大过程中偏振态变化情况。

Radially polarized beam purity detection and evaluation of polarization distribution characteristics

The uniformity of polarization distribution in the cross section of the beam is a key factor affecting the quality of the radially polarized beam and its practical application. The polarization purity of the radially polarized beam was measured and compared by the PBS measurement method, the slit method and the S-wave plate method, the uniformity of the polarization state of the radially polarized beam in the cross section was analyzed. In the process of measuring the radially polarized beam by the PBS measurement method and the slit method, the expression of the radial polarization purity was given, and the purity of the radially polarized beam was determined to be 93.4% and 84.1%, respectively. And the variance formula was used to evaluate uniform distribution of the radial polarization states. Among them, the PBS measurement method expressed the purity of the radially polarized beam more accurately, and the slit method can reflect the polarization distribution characteristics of the radially polarized beam more accurately by comparing the polarization degrees of different regions. The S-wave plate method can indirectly measure the purity of the radially polarized beam using the existing polarization analyzer in the market, and is more suitable for measuring the change of the polarization state of the radially polarized beam during the amplification process.