利用液体透镜进行变焦系统设计可以大幅降低系统的复杂程度，本文介绍和讨论了该项技术的研究和应用现状。首先，基于液体透镜的分类即渐变折射率透镜和变曲率透镜介绍了几种主要液体透镜的原理和特点，给出了具有代表性的ARCTIC透镜系列和Optotune透镜系列的设计参数和优点。然后，对液体透镜技术在变焦系统中的应用进行了分析，描述了其在变焦眼镜、手机相机、内窥镜和显微镜等诸多领域中应用的现状和优势。最后，利用液体透镜设计了一种长焦距变焦系统，该系统可实现2.5倍的可见光变焦。

Zoom lens design with liquid lenses is a novel method to greatly reduce the complication of the whole system. This paper reviews the research situation and applications of the technology. Firstly, the principles and characteristics of the some types of liquid lenses are introduced according to the lens classifications on gradient refractive index lenses and variable curvature lenses. The specifications and advantages of several typical lens series such as ARCTIC lens series and Optotune lens series are given. Then, applications of liquid lens in zoom systems are analyzed, and their advantages in focus-tunable glasses, cell phone camera lenses, endoscopes and several types of microscopies are described. Finally, based on a liquid lens, a long focus zoom system with a high zoom ratio of 2.5 is designed for visible light.