Journal ArticleDOI
Birefringence measurement using rotating analyzer approach and quadrature cross points
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TLDR
A new technique for birefringence measurement and extracting the coefficients of the dispersion relation such as Cauchy or Sellmeier equations is proposed and has been done on two different kinds of nematic liquid crystal wave plates.Abstract:
A new technique for birefringence measurement and extracting the coefficients of the dispersion relation such as Cauchy or Sellmeier equations is proposed. The main principle of the technique is based on finding accurately the wavelengths that the birefringent plate operates as a quarter-wave plate (QWP) and measuring the birefringence at these points. As the projections of the ordinary and extraordinary beams on the analyzer axis interfere, the setup is a form of common path interferometer and these QWP points are the quadrature points at which the sensitivity of the interferometer is optimum. An algorithm is developed to find these crossing points precisely. Implementation of this technique has been done on two different kinds of nematic liquid crystal wave plates made of Merck E44 and BL036.read more
Citations
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Lateral substituent effects on UV stability of high-birefringence liquid crystals with the diaryl-diacetylene core: DFT/TD-DFT study
TL;DR: In this paper, the effect of the lateral substituents on the UV stability of high birefringence liquid crystals (LCs) was studied using the DFT/B3LYP/6-311G (d, p) method.
Journal ArticleDOI
Optical system for measuring the spectral retardance function in an extended range
Abdelghafour Messaadi,María del Mar Sánchez-López,Pascuala García-Martínez,Asticio Vargas,Ignacio Moreno +4 more
TL;DR: In this paper, the authors apply a well-known technique for determining the spectral retardance by measuring the transmission spectra between crossed or parallel polarizers in a wide spectral range covering the visible and near infrared (NIR) spectrum in the range from 400 to 1600 nm.
Journal ArticleDOI
Improving target discrimination ability of active polarization imagers by spectral broadening.
TL;DR: It is shown that broadening the spectrum of the light entering the system can increase the contrast between two regions of a scene and can be further increased by taking into account the spectral dependence of the scene and of the polarimetric properties of the imaging system in the optimization of the measurement procedure.
Journal ArticleDOI
Phase interrogation birefringent-refraction sensor for refractive index variation measurements
Ruey-Ching Twu,Chia-Wei Hsueh +1 more
TL;DR: In this article, a birefringent-refraction (BR) sensor for measuring refractive indices of liquid solutions based on phase interrogation in a heterodyne interferometer is proposed.
Journal ArticleDOI
A Resolution-Enhanced Digital Micromirror Device (DMD) Projection System
TL;DR: In this article, the authors presented a resolutionenhanced system for digital micromirror device (DMD) projected images by utilizing time multiplexing and birefringence in order to achieve this with static components only.
References
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Journal ArticleDOI
Birefringence dispersions of liquid crystals.
TL;DR: T theory on the quantitative birefringence dispersions of liquid crystals was developed and found to have excellent agreement with experimental results throughout the entire visible and infrared spectral regions.
Journal ArticleDOI
Birefringence measurements of liquid crystals
Shin-Tson Wu,Uzi Efron,L.D. Hess +2 more
TL;DR: A liquid crystal based phase retardation plate which can be voltage tuned and calibrated to provide any degree of phase shift from 0 to 2π over a wide wavelength range (0.4–16 μm) is discussed.
Journal ArticleDOI
Refractive indices of liquid crystals for display applications
TL;DR: In this paper, the authors reviewed the extended Cauchy model and the four-parameter model for describing the wavelength and temperature effects of liquid crystal (LC) refractive indices.
Journal ArticleDOI
Extended Cauchy equations for the refractive indices of liquid crystals
Jun Li,Shin-Tson Wu +1 more
TL;DR: In this article, the Vuks equation was used to describe the wavelength and temperature-dependent refractive indices of liquid crystal compounds and mixtures, which fit experimental data well in the off-resonance spectral region.