Low-voltage driving high-resistance liquid crystal micro-lens with electrically tunable depth of field for the light field imaging system

Abstract

Light field imaging (LFI) based on Liquid crystal microlens array (LC MLAs) are emerging as a significant area for 3D imaging technology in the field of upcoming Internet of things and artificial intelligence era. However, in scenes of LFI through conventional MLAs, such as biological imaging and medicine imaging, the quality of imaging reconstruction will be severely reduced due to the limited depth of field. Here, we are proposed a low-voltage driving LC MLAs with electrically tunable depth of field (DOF) for the LFI system. An aluminum-doped zinc oxide (AZO) film was deposited on the top of the hole-patterned driven-electrode arrays and used as a high resistance (Hi-R) layer, a uniform gradient electric field was obtained across the sandwiched LC cell. Experimental results confirm that the proposed LC MLAs possess high-quality interference rings and tunable focal length at a lower working voltage. In addition, the focal lengths are tunable from 3.93 to 2.62 mm and the DOF are adjustable from 15.60 to 1.23 mm. The experiments demonstrated that the LFI system based on the proposed structure can clearly capture 3D information of the insets with enlarged depths by changing the working voltage and driving frequency, which indicates that the tunable DOF LC MLAs have a potential application prospects for the biological and medical imaging.

Four-channel voltage-driven cylindrical liquid crystal lenses with a laterally shiftable optical axis

“…LC lenses have been applied in many fields, such as imaging system [2][3][4][5][6], auto focus [7], optical tweeze [8,9], et.at,. In recent years, 3D display has become a research focus to enhance visual experience, and cylindrical LC lenses commonly used to increase depth of field [10][11][12][13][14] and enable switching between 2D and 3D display [15][16][17][18][19][20]. Although many structures of cylindrical LC lenses have been proposed [21][22][23][24][25][26], there are still some issues that need to be addressed, such as high driving voltage, complex control, complicated fabrication processes, and large aberrations.…”