Controllable pretilt angle of liquid crystals with the formation of microgrooves

This work investigates the controllability of the pretilt angle of liquid crystals (LCs) in a cell with an initial vertical alignment through microgrooves induced by the holographic fast-writing method. By changing the writing time or intensity of the pumped beam, the microgrooves with various surface modulations can form and provide distinct planar anchoring strength for the LCs. The pretilt angle of the LCs can be controlled over a range from 18.3 degrees to 89 degrees. The writing time of the microgrooves takes less than 25 s, which is a two-fold reduction in the time taken in previous investigations using other photoaligned methods.