反射式离轴数字全息显微光强参数研究

Light intensity parameters of reflective off-axis digital holography

为了探究光强参数对于反射式离轴数字全息显微再现像质量的影响,概述了数字全息显微技术的研究现状以及影响全息图再现像质量的因素,基于菲涅尔衍射积分,论述了离轴数字全息图的记录与再现像过程,分析了一定记录距离下物光和参考光光强比对于全息图再现像质量的影响。通过控制物光路以及参考光路中滤光片的滤光能力来实现不同的物参光强比,从而记录下标准分辨率板的反射式显微全息图并进行重构。其实验结果表明:在记录距离已知的情况下,物光和参考光的光强比对反射式显微全息图再现像质量有着显著影响。因此在保证其他实验条件不变的情况下,确定适当的物参光强比是提高全息图质量的关键。通过理论分析,确定了实验的记录距离,并对该记录距离下的频谱图进行分析,验证记录距离的正确性。在相同记录距离下进行不同物参光强比下的对比实验,确定了可以实现较好重构效果的物参光强比范围。实验结果亦为进一步研究基于反射式数字全息的三维重构提供了理论依据与技术条件。

This paper summarizes the research status of digital holography microscopy technology and factors affecting the quality of the reconstructed image of hologram in order to investigate the influence of object light intensity parameters on the quality of reconstructed image of reflective off-axis digital holography. Based on Finel diffraction integral,the process of recording and reproducing the off-axis digital hologram is discussed. The influence of object light intensity and reference light intensity ratio on the reconstructed image quality of hologram is analyzed. The standard resolution plate is the research object.By controlling the filtering capability of filter in the object light and reference light path,we can achieve different light intensity ratio of material reference,and record the reflection hologram of standard resolution plate and reconstruct it. The experimental results show that the object and reference light intensity ratio have a significant impact on the quality of hologram recurrent image when the recording distance is known. Therefore,it’s the key to determining an appropriate recording distance and the object and reference light intensity ratio for improving the quality of hologram under the condition that other experimental conditions remain unchanged. Through theoretical analysis,the recording distance of the experiment is determined,and the spectrum chart under the recording distance is analyzed to verify the correctness of the recording distance. Under the same record distance,the contrast experiment of light intensity ratio of different material reference is carried out,and the range of light intensity ratio of material reference which can achieve better reconstruction effect is determined. The experimental result will provide theoretical basis and technical conditions for studying the reflective digital holography based on three-dimensional reconstruction.