基于标量衍射理论建立了光谱色散平滑（SSD)、随机相位板（RPP）和偏振匀滑（PS）联用的光束匀滑方案数值仿真模型。以斑纹对比度和偏振度为主要评价参量，利用该模型研究了径向偏振调制的匀滑及消偏振特性。研究表明，径向偏振调制可以有效降低聚焦光斑斑纹对比度和偏振度。使用半波片拼接方式产生近似径向偏振光时，拼接单元数对匀滑及偏振特性影响较小，8片拼接的匀滑效果已与理想径向偏振光几乎一致。对比分析了径向偏振调制、正交偏振调制和双折射楔三种PS方式，结果表明，由于三种PS方式本质上的一致性，光束的匀滑及偏振特性差别较小。

Numerical calculation model of beam smoothing is established based on scalar diffraction theory. The model takes account of smoothing by spectral dispersion (SSD), random phase plate (RPP), and polarization smoothing (PS). Effect of radial polarization modulation on smoothing and polarization properties of focal speckle is studied based on the model. Speckle contrast and polarization degree are used to characterize smoothing and polarization properties, respectively. The results show that contrast and polarization degree of focal speckle can be reduced by radial polarization modulation. Approximately radially polarized beam can be generated by polarization control plate (PCP) made by jointing several half-wave plates. The influence on smoothing and polarization properties of the number of half-wave plates is relatively small. Actually, the effect of an approximately radially polarized beam generated by 8 half-wave plates is nearly the same as that of a perfectly radially polarized beam. Three methods for polarization smoothing (radial polarization modulation, orthogonal polarization modulation and using birefringent wedge) are analyzed and compared, and the results show that the effects of the three methods are similar.