基于数字全息显微术的液体透镜参数测量方法

Measurement of Liquid Lens Parameters Based on Digital Holographic Microscopy

提出了一种利用数字全息显微术测量液体透镜表面曲率半径及焦距参数的实验方法。针对液体透镜表面不能接触、直径较小、侧壁材料非透明等因素,采用具有像差校正功能的立式马赫-曾德尔干涉仪光路实验记录液体透镜液面的数字全息图,数值再现得到携带液面信息的物光波前相位分布信息,并经数值计算和拟合得到液面轮廓曲线,最终得出液面曲率半径以及液体透镜的焦距等参数,进而利用该方法对标准平凹透镜的曲率半径和焦距等参数进行了测量,以验证其正确性。结果表明,所提出的方法是一种高精度、非接触测量液体透镜液面曲率及焦距参数的有效手段。

We present an experimental method to measure the curvature radius and focal length of liquid lens based on digital holographic microscopy.Considering the features of liquid lens such as non-contact,small size and nontransparent wall,a vertical optical path based on Mach-Zehnder interferometer with aberration correction capacity is used to record the hologram of sample.The phase distribution of the object wavefront carrying the liquid level information is numerically reconstructed from the recorded digital hologram and the surface contour curve is achieved by numerical computation and fitting.Then the curvature radius and focal length of the liquid lens can be obtained.In order to certify the validity of this method,a standard plano-concave lens is measured.The experimental results show that this method is an effective approach with high precision and non-contact for measuring the curvature radius and focal length of liquid lens.