Chinese Journal of Liquid Crystals and Displays, Volume. 38, Issue 9, 1178(2023)
Laser scanning device and response speed modulation based on VA liquid crystal
In this work, the vertically aligned (VA) liquid crystal devices are prepared on a substrate with serrated ITO electrodes, the laser is coupled into the liquid crystal layer, and the voltage of the ITO electrodes is modulated. The output laser achieves deflection and the deflection angle increases with the increase of voltage until saturation. Under two serrated electrodes with a top angle of 20°, the laser spot deflects by about 4°. At the same time, since the voltage used for driving liquid crystals is an AC signal, by adjusting the minimum driving voltage, which is the bias voltage, the liquid crystal molecules start to rotate from a certain starting angle and are also driven within their fast rotation range, thereby improving the response speed of the liquid crystal molecules.Under the guidance of this strategy, the state and driving speed of liquid crystal molecules are determined by characterizing their polarization state during their rotation. Under the premise of balancing the refractive index and driving speed, the overall response speed of liquid crystal layer molecules under different bias voltages is compared. Under a certain bias voltage, the response time driven by the liquid crystal layer decreases from 55 ms to 2.5 ms, while the relaxation time after power outage decreases from 18 ms to 8.5 ms. This provides a new solution for laser deflection devices using this liquid crystal layer scheme to achieve faster scanning frequency and scanning angle in the future.
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Hong-jun LIU, Cheng-feng QIU, Zhao-jun LIU. Laser scanning device and response speed modulation based on VA liquid crystal[J]. Chinese Journal of Liquid Crystals and Displays, 2023, 38(9): 1178
Category: Research Articles
Received: May. 9, 2023
Accepted: --
Published Online: Sep. 19, 2023
The Author Email: Cheng-feng QIU (qiucf@sitan.org), Zhao-jun LIU (liuzj@sustech.edu.cn)