Study on electrical characteristics of nematic liquid crystal cells under high-frequency pulsed driving

Liquid crystal on silicon (LCoS) has become a mainstream technology in modern display and photonic applications. High-frequency pulsed driving (HFPD) is often required to achieve high-spatial-bandwidth modulation. However, the transient electrical response of nematic liquid crystal (NLC) cells under HFPD still lacks a clear circuit-level description. Based on the Ericksen–Leslie (EL) director dynamic equation with rotational inertia and Maxwell’s displacement-current relation, this work develops a dual resistor-capacitor (dual-RC) equivalent-circuit model for NLC cells under HFPD conditions. The results show that the director dynamics are governed by two distinct time constants: a fast response dominated by rotational inertia and a slow relaxation process dominated by viscous effects. Within this framework, the transient electrical response of the liquid crystal (LC) cell can be effectively represented by a parallel dual-RC equivalent circuit, in which the two branches correspond to the inertial fast response and the viscous relaxation process. Conventional single-branch resistor-capacitor (RC) models are generally used under static or low-frequency conditions. In contrast, the proposed model maps two dynamic processes with different physical origins onto two RC branches. This mapping gives a clearer physical connection between director dynamics and the transient electrical response under HFPD. The proposed model is validated by simulations performed using the PSpice circuit-simulation platform and experimental measurements performed on a customized electrical characterization platform. Over the frequency range from 1 kHz to 10 kHz, good agreement between theoretical predictions and experimental results is obtained under both square-wave and sinusoidal driving conditions. These results provide a circuit-level reference for future analyses of waveform-dependent output stability and dynamic power consumption in LCoS driving circuits, and help in the design and optimization of LCoS-based display and photonic systems.