论文部分内容阅读
将散斑场的研究拓展到超快激光领域,进而引入了超快散斑的概念。首先在理论上研究了超快脉冲照明随机粗糙表面在菲涅耳衍射区域形成的超快散斑光场及其自相关函数,然后利用光场的自相关、强度系综平均和强度自相关等统计函数导出散斑强度自相关函数。发现超快散斑的强度相关随着时间的推迟逐渐呈现出周期性振荡的特征,且振荡频率依次增大。利用对菲涅耳衍射区超快散斑场的计算模拟,发现了诸如散斑颗粒随时间逐渐增大、颗粒中出现频率越来越大的干涉条纹以及干涉条纹由观察面两侧向中心方向依次消失等一系列全新的动态演化规律。
The research of speckle field is extended to the field of ultrafast laser, which leads to the concept of ultrafast speckle. Firstly, the ultrafast speckle light field and its autocorrelation function formed by the Fresnel diffraction region on the random rough surface of ultrafast pulse illumination were studied theoretically. Then the autocorrelation of the light field, the ensemble average intensity and the autocorrelation Statistical Functions Derive the Speckle Intensity Autocorrelation Function. It is found that the intensity correlation of ultrafast speckle gradually shows the characteristics of periodic oscillations with the delay of time, and the oscillation frequency increases in turn. Using the computational simulation of ultrafast speckle fields in the Fresnel diffraction region, it was found that interference fringes, such as speckle particles gradually increasing in frequency with increasing frequency in the particles, and interference fringes ranging from two sides of the viewing plane toward the center Followed by the disappearance of a series of new dynamic evolution.