Optimizing low frequency electro-optic response of nematic liquid crystals

摘要

Optimized enhanced electro-optic (EO) response of nematic liquid crystals (NLC) driven by low modulation frequency AM electric signal is investigated. A perturbed non-uniform transmitted output signal was observed at modulating frequencies (f(m)) lower than 80 Hz due to the effect of free charges, and optimized uniform response is achieved by adding a small holding voltage to the AM driving signal. The minimum applied holding voltage required for attaining uniform response at frequencies < 80 Hz decreases as the modulating signal frequency increase. As the frequency increases from 10 Hz to 70 Hz, the total response time decreases from 8.8 ms to 4.7 ms at field strength 1.2 V/mu m and at holding voltage (V-h,); 1.95V and 0.7 V (peak voltage), respectively. By such way the response times is effectively stabilized and enhanced for NLC low frequency EO applications.