ABSTRACT
A double-layer liquid crystal (LC) lens array with composited dielectric layer is proposed. In our design, a spatially non-uniform electric field is generated between the strip electrodes, resulting in a gradient refractive index distribution in the LC layer. Since the upper and lower parts of the LC lens array both adopt a composite dielectric layer, the operation voltage of the LC lens array is effectively reduced. In terms of LC lenslet, the double-layer design doubles the phase difference between the centre and the periphery of the LC layer, thereby reducing the focal length of the LC lens array. In addition, the shortest focal length (~1.78 mm) of the LC lens array is obtained at V = 3.3 V, and the LC lens array has a large focusing range.
Graphical abstract
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Acknowledgments
The work is supported by the National Natural Science Foundation of China under Grant No. 61535007 and the Equipment Research Program in Advance of China under Grant No. JZX2017-1570/Y464.
Disclosure statement
No potential conflict of interest was reported by the authors.