A Two-Dimensional Pretilt Angle Distribution Measurement of Twisted Nematic Liquid Crystal Cells Using Stokes Parameters at Plural Wavelengths

Abstract

We propose a Stokes parameter method for determining two-dimensional (2D) cell parameter distributions such as a pretilt angle in addition to the cell thickness and the twist angle of the twisted nematic liquid crystal display (TNLCD) by measuring Stokes parameters at plural wavelengths including a near-infrared region. The cell thickness and twist angle can be determined simultaneously by measurements of Stokes parameters at only one wavelength. The 2D cell parameter distributions of full-color LCDs can be obtained using near-infrared light. The pretilt angle can also be determined using at least two wavelengths. Measurement fluctuations or errors in cell parameters decrease with increasing wavelengths and are discussed in detail.