菲涅尔数字全息的脉冲响应

数字全息是用CCD记录全息图并用计算机数值重建全息像的一种全息新方法.在数字全息中,通过对不同记录参数下记录的全息图的数值处理,可以消除零级光和共轭光,从而将数字全息系统看作是一个线性系统.本文依据全息理论和付里叶频谱分析,对菲涅尔数字全息系统的脉冲响应和分辨本领进行了理论分析.结果表明,在矩形等间隔抽样的情形下,菲涅尔数字全息的脉冲响应是由CCD有限大小的孔径衍射斑调制的矩形函数;菲涅尔数字全息的分辨率由CCD的孔径尺寸决定;由于CCD像素具有一定的大小,使得点光源的像发生弥散.

The impulse response of Fresnel digital holography

The digital holography is a new method of holography to replaced the hologram plate by a CCD array and to substitute for the optical reconstruction process by a numerical calculation of the complex wave field in the computer.In the digital holography,the zero-light and conjugate light can be eliminated by numerically processing the holograms of object with different recording parameters and the digital holography system can be interpreted as a linear system.In this paper,By use of the holographic theory and Fourier transform spectrum analysis,The impulse response and resolving power of Fresnel digital holography is presented.The results show:the impulse response is a rectangle function modulated by diffraction factor of the aperture defined by the CCD;The resolving power of Fresnel digital holography is defined by the aperture of the CCD;the image size of impulse function is defined by the size of the CCD pixel.