Analysis Technique for Wavelength Dispersion of Refractive Indices by Renormalized Transmission Spectroscopic Ellipsometry

Abstract

An improved analysis technique to determine the wavelength dispersion of refractive indices based on renormalized transmission spectroscopic ellipsometry was demonstrated. Twelve device parameters, including cell gap, twist angle, and rotation angle, nine Cauchy coefficients for birefringence, and refractive indices for ordinary and extraordinary rays are determined in a three-step manner. The refractive index for an ordinary ray at the wavelength λ=589.0 nm, which is measured by using an Abbe refractometer, is substituted as an original refractive index to guarantee the accuracy of the analysis for the absolute value of refractive indices. Compared with our previous technique, this analysis procedure is more simplified; as a result, the reproducibility and applicability were remarkably enhanced.

Evaluation of azimuthal anchoring energy for liquid crystal device equipped with color filter by means of renormalized transmission ellipsometry

“…The azimuthal anchoring energy can be determined by substituting obtained d and f t from the numerical calculations for Eq. (19). The obtained azimuthal anchoring energy for the LC cells assembled using AL-1254 and PIA-X001 equipped with/without a color filter as a function of the rubbing strength is shown in Fig.…”

“…By using the extended Cauchy equation, the expression of the refractive indices of ordinary and extraordinary rays of NLC is described as where α i and β i represent the i th Cauchy coefficients and λ is the wavelength in micrometers. The Cauchy coefficients of ZLI‐4792 are shown in Table and were determined by means of RTE …”

“…The Cauchy coefficients of ZLI-4792 are shown in Table 2 and were determined by means of RTE. 19,23,24 In this experiment, a color filter laminated on a glass substrate is employed. Here, the alternating stripe patterns of red, green, and blue of color filters are 100 mm, and the thickness of the glass substrate is 0.7 mm.…”

“…The expression of Δ and Ψ in the Eq. () is the same as that in the equation of the conventional RTE . It is assumed that no influence in the obtained Δ and Ψ from the ellipsometric measurements between the conventional RTE and RTE equipped with a color filter is found when a color filter is an isotropic medium.…”

Evaluation technique of cell thickness, pretilt angle, and twist angle for guest–host liquid crystal displays

“…Here, the elastic constants of the mixture of 5CB and the merocyanine dye were assumed to be the same as those of pure 5CB, i.e., K 11 6.37, K 22 3.81, and K 33 8.60 pN at 25°C. The refractive indices of ordinary and extraordinary rays for 5CB, which were preliminarily determined in our previous study [22,23], are listed in Table 1.…”