(Received August 26, 2003; accepted October 27, 2003; published February 10, 2004)
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.
KEYWORDS:nematic liquid crystal cell, Stokes parameters, several wavelengths, cell thickness, twist angle, pretilt angle, Jones matrix representation