摘要
利用部分相干光理论对多色光源照明下光栅的菲涅耳衍射进行了理论分析 ,得到了适用于任意发光类型(脉冲或连续发光 )的多色光源的衍射光强的一般公式 ,理论结果表明菲涅耳衍射区的平均衍射光强的形式只与光源的频谱分布有关 ,这对借助于连续发光光源来研究脉冲光源照明下光栅的塔尔博特效应以及用来确定脉冲光源的性能参量提供了有力的参考依据。此外 ,详细讨论了光源的频谱分布对光栅塔尔博特效应的影响并进行了相应的数值计算。实验中通过选用不同频率的激光分别照明光栅 ,拍摄到对应于不同频率的衍射光强分布图像 ,从而间接获得多色光同时照明光栅时总的衍射光强分布。实验结果表明 ,理论和实验符合较好。
Fresnel diffraction of the grating illuminated with the polychromatic light source is theoretically analyzed with the theory of partially coherent light, and the general formula of the diffraction intensity of the grating is obtained. This formula is applicable to any kind of illuminance pulsed or CW. The theoretic results show that the average diffractive intensity distributions of the grating illuminated by the different source with the same spectrum are the same. This conclusion will be helpful for the study of the Fresnel diffraction of the grating illuminated by the time-dependent source, and it provides a method to measure the performance parameters of the ultra-short pulse laser. Moreover, the influence of the spectra of the light on the Talbot image of the grating at different Talbot distance is discussed, and the diffraction intensity distribution of the grating illuminated by the polychromatic light with different spectrum width is numerically calculated. In the experiment, three light sources with different frequency are chosen to illuminate the grating respectively, then photos of three diffraction intensity distributions are taken and the total diffraction intensity distribution of the grating illuminated by the polychromatic light is indirectly obtained. The experimental results conform well with the theoretic ones.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2004年第6期859-864,共6页
Acta Optica Sinica
基金
国家科技部 (2 0 0 2CCA0 35 0 0 )资助课题
