GS算法设计连续相位板时相位滤波器的选择

Choice of phase filter in designing continuous phase plate with GS algorithm

针对GS算法在设计连续相位板(CPP)时,迭代过程在解包相位中引入的高频调制,研究了初始相位与解包相位的频谱分布特性,并对两者的差别进行了比较。根据初始相位的频谱特性,提出了以初始相位的频域截止频率为相位滤波器的截止频率的滤波器选择方法。利用该方法进行了CPP设计,设计结果对应的远场焦斑参数为:均方根误差0.267 2,能量利用率96.32%,顶部不均匀度0.101 2。

The spectrum characteristics of initial phase and unwrapped phase have been analyzed respectively.The differences between the spectrum characteristics show that some high frequency modulation would be led into the unwrapped phase in the iterative process.According to the analysis and comparison,the cut-off frequency of phase filter should be equal to the cut-off frequency of initial phase in frequency-domain.Using this method,a continuous phase plate has been simulated,and the mean square error,energy utilization rate and top non-uniformity which corresponded to the far field spot are 0.267 2,96.32% and 0.101 2.