基于分数阶傅里叶变换的超短脉冲线性啁啾分析

为了利用分数阶傅里叶变换有效地检测出信号的啁啾系数,由分数阶傅里叶变换的原理出发,从理论上推导了变换阶次与超短脉冲啁啾系数的关系。以高斯型线性啁啾脉冲为例,利用自编程序进行了数值模拟。根据分数傅里叶变换在特定阶次上呈现能量高度聚集性的特点,画出变换阶次与变换结果的关系图,找到对应的最佳阶次,求出啁啾系数。结果表明,模拟结果和理论结果得到了很好的吻合。这为以后分析啁啾参量提供了参考。

Characterization of linear chirped ultrashort pulse based on fractional-order Fourier transform

In order to use fractional-order Fourier transform ( FRFT ) to effectively detect coefficient of chirp signal , characterization of linear chirped ultrashort pulse was studied based on FRFT . FRFT has characteristics of high energy aggregation in an optimal order .According to the characterization , the relationship between optimal order and chirped coefficient of ultrashort pulse was proved theoretically .Numerical simulation was done for Gaussian linear-chirped pulse .The relationship curve between the fractional order and the maximum of the result of FRFT was drawn .The results show that the theoretical formula is in agreement with numerical simulation .The conclusion can provide reference for discussing chirp coefficient of ultrashort pulse .