利用Jones矩阵法，理论上分析了方位角分别为 0°和-45°的2个可变相位延迟器组成的偏振转换器可实现任意偏振态到水平线偏振态的转换，并推导出可变相位延迟器延迟量的表达式。利用自主研制的液晶相位可变延迟器的相位延迟，在1V～2.7V范围，根据驱动电压连续线性可调的特性, 设计了两片液晶可变相位延迟器组成的偏振态转换器，实现了随机偏振态(Stokes参数为(-0.567，0.752，0.36))到水平偏振态(Stokes参数为(1，0，0))的可控调制，实验结果验证了理论分析结果。该偏振态转换器还可以实现其他任意偏振态到水平偏振态的调制。

By using Jones matrix method, it is derived that polarization converter with two variable retarders oriented at 0° and -45° transforms random polarization state to horizontally linear polarization, and the expression of retardation is given. Liquid-crystal variable retarder (LCVR) was developed, and the retardation was linearly proportional to applied voltage ranging from 1V to 2.7V. In addition, polarization converter based on two LCVRs was designed, and it was able to change any given polarization state (Stokes parameters described as (-0.567，0.752，0.36)) to horizontally linear polarization state (Stokes parameters described as (1，0，0)). The theoretical analysis and experimental result are presented.