The optical properties of twisted nematic liquid crystal structures with twist angles ⩽90 degrees
| Autor: | C H Gooch, H A Tarry |
|---|---|
| Rok vydání: | 1975 |
| Předmět: |
Physics
Acoustics and Ultrasonics Condensed matter physics Biaxial nematic business.industry Polarizer Elliptical polarization Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Condensed Matter::Soft Condensed Matter Optics law Liquid crystal Perpendicular Twist business Anisotropy Refractive index |
| Zdroj: | Journal of Physics D: Applied Physics. 8:1575-1584 |
| ISSN: | 1361-6463 0022-3727 |
| DOI: | 10.1088/0022-3727/8/13/020 |
| Popis: | Liquid-crystal twisted nematic structures can be made with twist angles other than the conventional 90 degrees . It is shown that theoretically the transmission of such a structure when placed between two polarizers aligned parallel and perpendicular to the respective surface molecular directors is given by T=(1+u2)-1 sin2( theta (1+u2)12/) where u= pi d Delta n/ theta lambda , and theta is the twist angle, d being the cell thickness, Delta n the refractive index anisotropy of the nematic material, and lambda the wavelength of the transmitted radiation. In the idealized case T is taken to be zero. The departures from this, predicted by the above expression, are due to the fact that plane-polarized light becomes elliptically polarized as it passes through the nematic structure. Experiments confirm the validity of the theoretical model. |
| Databáze: | OpenAIRE |
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