数字全息参数优化

摘要

为了提高数字全息图的质量,文中从菲涅尔衍射积分出发,从理论上分析重构距离对全息图质量的影响.采用重构图的平均梯度为判断重构距离的标准,并通过参数调整重构距离的精度,提出了自动调整重构距离的方法,并设计离轴数字全息光路对其进行实验.实验结果表明:该方法可以显著提高全息图的质量.其中为了避免物光受共轭物光与零级像的干扰,在衍射场宽度的基础上,建立了CCD平面、重建像与参考光方向的模型,通过分析参考光与各个坐标轴之间的角度,推导出参考光角度的公式,通过分析与实验表明公式对参考光角度的可控性.%In order to improve the quality of digital hologram,the paper theoretically analyzes the influ-ence of reconstruction distance on the quality of hologram based on Fresnel diffraction. The average gra-dient of the reconstructed image is used as the standard to judge the reconstruction distance,and the pre-cision of reconstruction distance is adjusted by parameters. A method of adjusting the reconstruction dis-tance is proposed,and the experiment of off-axis digital holography is designed. The experimental results show that this method can improve the quality of hologram. In order to avoid the interference of the ob-ject light by the zero-order and twin-image,a model of the CCD plane,reconstructed image and the di-rection of the reference light is established on the basis of the diffraction field width. By analyzing the angle between the reference beam and each axis, a formula of the angle of the reference light is de-duced. Experiments show the controllability of the formula to the angle of reference light.