With today's organic photopolymer materials allowing high resolution, it is possible to record subwavelength volume holographic index gratings, i.e. index gratings with a period much smaller than the wavelength operating in the form birefringence regime. Such components are of interest for the direct view liquid crystal displays that suffer from a narrow viewing angle. In fact, by providing high birefringence, they compensate the intrinsic birefringence of the liquid crystal and thus, improve the viewing angle properties of the liquid crystal displays. Recently, we introduced a hybrid holographic compensator combining an "in plane" commercially available birefringent film and a slanted optical-axis subwavelength volume index grating recorded in a Dupont photopolymer. In this paper, we present the hybrid holographic compensation and its interesting features for TN-LCD viewing angle improvement. More particularly, a hybrid holographic compensator is designed for avionics application. It is based on a 120nm-period volume index gratings achieving an index modulation of 0.045 with a 33 degrees -slant angle of the optical axis. The hybrid holographic compensator was manufactured and implemented on an avionics equipment from Thales Avionics. Visual inspection as well as contrast measurements showed a good improvement of the viewing angle characteristics.
Subwavelength volume holographic grating in photopolymer for the liquid crystal display viewing angle compensation
2003
8 Seiten, 16 Quellen
Aufsatz (Konferenz)
Englisch
Holographic grating recorded in photopolymer composed of photosensitive polymer binder [4929-36]
British Library Conference Proceedings | 2002
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