关键词: 电润湿/
液体透镜/
焦距/
动态过程
English Abstract
Test and analysis of the dynamic procedure for electrowetting-based liquid lens under alternating current voltage
Xie Na1,2,Zhang Ning1,
Zhao Rui3,
Chen Tao3,
Hao Li-Li2,
Xu Rong-Qing2
1.School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China;
2.Institute of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China;
3.School of Optoelectronic Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
Fund Project:Project supported by the National Natural Science Foundation of China (Grant No. 61302155), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20151508), and the Nanjing University of Posts and Telecommunications Foundation, China (Grant No. NY215163).Received Date:17 February 2016
Accepted Date:23 August 2016
Published Online:05 November 2016
Abstract:An experimental setup used to measure the important optical properties of electrowetting liquid lens is proposed. The simple and precise method of measuring dynamic responses and focal lengths of liquid lens under different excitation signals is based on Gaussian beam transmission theory. The measurement method can be widely used in all kinds of zoom lens systems. The device is simple and economical, and also has the advantages of convenient operation, high measurement precision and wide range measurement. This work provides a new way to study the dynamic response of electrowetting liquid lens and the the mechanism of electrowetting liquid lens.The fabrication process and some relevant noticeable points for the homemade liquid lens are introduced. The testing device of dynamic process of lens consists of a He-Ne laser, an electrowetting lens, a circular diaphragm, a phototube, a digital storage oscilloscope and a computer. The change of the focal length of liquid lens due to the applied voltage will affect the flux detected by the photoelectric receivers. It is proved according to Gaussian beam transmission theory that the light flux received by the phototube changes with time, which represents the relationship between the focal length and time and the dynamic characteristics of the liquid lens. Therefore, the intensity of output signal of photoelectric receiver reflects the focal length of liquid lens.A dynamic changing process of the focal length of a self-regulating varifocal liquid lens based on electrowetting technology is tested under alternating current signal. It shows that the focal length of the liquid lens changes with the corresponding amplitude and polarity of the sine voltage. In one cycle, 4 peak signals of 50 Hz appear in turn, and the peak amplitude increases with the increase of voltage. Peaks 1 and 2 are caused by the voltage polarity, while peaks 3 and 4 by the oscillation modes. This is due to the fact that the liquid surface changes with time in the spherical shape under low voltage, but it will generate new oscillation mode when the amplitude is high.
Keywords: eletrowetting/
liquid lens/
focal length/
dynamic procedure
