Use of a hybrid pseudospectral time-domain–finite-difference time-domain method for optical simulation of liquid crystals

Abstract

In order to reduce the computational cost of the finite-difference time-domain method, the pseudospectral time-domain method is applied to the glass substrate direction with a large surface and smooth internal media, while the finite-difference time-domain method is applied to the thickness direction of a cell with a small thickness and fine structures. A fast Fourier transform algorithm, instead of the central-difference in the finite-difference time-domain method, is used to represent the spatial derivatives in the pseudospectral time-domain method, which greatly reduces the spatial sampling rate in the glass substrate direction. Both the hybrid method and the finite-difference time-domain method are used to simulate the propagation of light through the same twisted nematic pixel in the on state for 100 fs. The maximum deviation of the transmittance obtained using both methods is less than 5.1%; the memory capacity and computational time required for the hybrid method are about 8.5% and 21% respectively compared with those required for the finite-difference time-domain method. The use of the hybrid method reduces the memory capacity and computational time required for the finite-difference time-domain method while its accuracy is preserved.

Keywords:

• liquid crystal
• optical simulation
• finite-difference time-domain method
• pseudospectral time-domain method

Acknowledgement

The authors thank the National Natural Science Foundation of China (No. 60878048) for its financial support.