Study of Ultra-Small Optical Anisotropy Profile of Rubbed Polyimide Film by using Transmission Ellipsometry

Abstract

Anisotropy profile of a rubbed polyimide film is investigated using both a modified ultra high precision transmission ellipsometer and the analysis software previously developed to determine the optic axis distribution of discotic liquid crystals in the wide view film. The distorted sinusoidal variation of the ellipsometric constants obtained at an oblique angle of incidence indicates that the optic axis varies from 14.7° to 40.6° from the sample plane. The magnitude and distribution of anisotropy is expressed in terms of n o , n e , and the cosine-shaped tilt angle distribution of the optic axis in a rubbed polyimide film.

Measuring the Thickness of Flakes of Hexagonal Boron Nitride Using the Change in Zero-Contrast Wavelength of Optical Contrast

“…Optical methods have been used to observe the properties of the thin film [15,16]. Here, to determine the thickness of an h-BN flake, we propose an improved method that is more accurate and effective than the standard optical reflectivitycontrast method.…”

Parametrization of the Optical Constants of AlAsxSb1-x Alloys in the Range 0.74-6.0 eV

“…The optical properties such as complex refractive index ñ = n + ik, dielectric function ε = ñ 2 = ε 1 + iε 2 , and interband transitions including the band gap of AlAsSb are needed for further device optimization [7], such as designs for distributed feedback grating waveguides [4] and simulations to predict the performance of solar cells [8,9]. As a result, the dielectric functions and critical point (CP) energies of AlAs x Sb 1-x have been investigated using spectroscopic ellipsometry (SE) [10,11], which is an excellent technique for determining ε data directly [12,13]. However, no analytic representation of these ε spectra as a continuous function of As-composition x has been reported to date.…”