点衍射干涉仪中小孔尺寸对衍射光强分布影响的研究

【作者】 褚光；

【导师】 高志山；

【作者基本信息】 南京理工大学 ， 光学工程， 2012， 硕士

【摘要】 点衍射干涉技术作为一种高精度的干涉测量手段,在军事和民用领域有着广泛的应用空间,其测量精度很大程度上取决于衍射小孔的尺寸。本文以点衍射干涉仪中的小孔部分为研究对象,研究了波长量级小孔的尺寸因素对衍射场光强分布的影响,得到了衍射场中光强分布随小孔尺寸变化的数值仿真方法。通过对标量衍射理论与矢量衍射理论的研究,分别以理想入射光波与含微小初级球差的入射光波为讨论对象,推导其经过波长量级小孔衍射后的光强表达式,并给出衍射光强随小孔尺寸变化的关系。通过数值计算,总结出利用标量衍射理论处理此类衍射问题时的失准现象,并分析其失准的原因。在采用矢量衍射理论研究波长量级小孔对衍射光强的影响时,从三种不同的理论角度出发,研究了衍射光强的表达形式,通过数值计算,得到了小孔的尺寸影响衍射光强分布的仿真数据。在数值计算阶段,通过MATLAB编写了衍射光强计算程序,能够适用于实验应用领域,为后续研究工作的开展提供了必要的数值计算工具,在实际应用中可以通过重置所需要的初始参数,模拟不同尺寸小孔产生的衍射光强分布,对实验工作有一定的指导意义。更多还原

【Abstract】 As a interference measuring method with high precision,the point-diffraction interference technique has a wide application space both in military and civil areas,the measurement accuracy mainly depends on the dimension of the pinhole.This paper has taken the pinhole part in point-diffraction interferometer as a background and researched effects by the pinhole with wavelength order to the intensity in diffraction field,obtained the result of the relation between the intensity in diffraction field and the pinhole’s dimension.From the study of the scalar and vector diffraction theory,this paper has taken the ideal incident light and the incident light with primary spherical aberration as investigated subject,achieved the computational formula of diffraction intensity produced by the pinhole with wavelength order,acquired the relation between the intensity in diffraction field and the pinhole’s dimension.According to the numerical calculation,this paper has summarized the data and reason of the inaccurate representation in using scalar diffraction theory to analyse the pinhole diffraction problem.Then using the vector diffraction theory to analyse the influence by pinhole in diffraction light intensity,achieve the same conclusion from three different theory views.This paper also has achieved the objective data and relation between pinhole’s dimension and diffraction light intensity from the numerical calculation,and verified the conclusion of electric field component’s leading role in the contribution to diffraction light intensiry.This paper has programmed several kinds of calculation method of the diffraction light intensity by MATLAB,providing the necessary numerical calculation method to the following research.To get the result of diffraction light intensity by differentpinhole’s dimension,the handle only need to alter initial parameters in the program. The useful conclusions and necessary programs in this paper will help the following research to get more achievements.更多还原