Abstract:
A wavelength converter which performs simultaneously wavelength conversion for a plurality of input light wavelengths that are unequally intervals, is provided. The nonlinear material of the wavelength converter has a modulation structure which has modulation of a nonlinear optical constant at a period Λ 0 in a propagating direction of light, a phase being continuously changed each period Λ 0 and a continuous phase modulation for a different period Λ ph being added to the modulation structure. The nonlinear material has a modulation structure obtained by changing a modulation curve for the phase modulation, wherein a phase mismatch Δβ is represented by Δβ = 2π(n 3 /λ 3 - n 2 /λ 2 - n 1 /λ 1 ), and at least three peaks at unequally intervals within a plurality of peaks for conversion efficiency represented by 2π/Λ 0 + 2πi/Λ f (i = m, m+1, ... , n: where m and n are positive or negative integers) have highest conversion efficiency.
Abstract:
L'invention concerne un dispositif de modulation spatiale d'un faisceau lumineux, comprenant un élément à cristal liquide dispersé dans du polymère (PDLC), ledit élément comprenant au moins deux zones pouvant être adressées indépendamment l'une de l'autre au moyen d'un système à au moins deux électrodes (31,32,33,...,411,412,413,...). Selon l'invention, lesdites électrodes présentent un motif prédéterminé non rectiligne (31,32,33,...), choisi de façon à réduire la sensibilité à la polarisation dudit dispositif, due à l'apparition d'au moins un champ électrique transverse entre lesdites au moins deux électrodes et ledit dispositif comprend également des moyens optiques de réduction de la sensibilité à la polarisation comprenant au moins une lame à retard de phase anisotrope (44,51).
Abstract:
In a vertically aligned mode LCD, a gate line and a storage line are formed on a substrate in parallel, and a storage electrode and a cover pattern are formed as branches of the storage line. The storage electrode is overlapped with an aperture of a common electrode formed on an upper substrate. The cover pattern is located between a pixel electrode and a data line to prevent a light leakage. Accordingly, an alignment error margin of the upper substrate and the lower substrate is increased, an aperture ratio is enhanced, and repairing the high pixel defect is possible. Further, the light leakage caused by a voltage of the data line is prevented.
Abstract:
A liquid crystal display device has a plurality of pixel elements, the optical transmissivity of which is varied by suitable electrical signals. The liquid crystal display device has electrodes which apply electric fields to a liquid crystal layer (50), the electric fields having components in a direction generally parallel to the liquid crystal layer (50). Each pixel element has at least one pixel electrode (1) which extends in a common direction as signal electrodes (12) and common electrodes (2) which extend over several pixel elements. The common electrodes (2) may be on the same side of the liquid crystal layer (50) as the pixel and signal electrodes (1,2), or they may be on opposite sides. Each pixel may have two pixel electrodes (1) with the signal electrode (12) therebetween and there are then a pair of common electrodes (2) with the pixel electrodes (1) therebetween. The common electrodes (2) may be common to adjacent pixel elements. The pixel electrodes (1) and the common electrodes (2) may be separated by an insulating film.
Abstract:
A liquid crystal device and a method of forming a liquid crystal device are disclosed. The device comprises a layer of liquid crystal material bounded by a first cell wall and a second cell wall, the first cell wall being provided with a first electrode structure and the second cell wall being provided with a second electrode structure. The first cell wall and the second cell wall are separated by a distance dc, wherein the layer of liquid crystal material is associated with a plurality of defect generation sites. Defects are generated by the defect generation sites, increasing switching speed and decreasing the time it takes to switch large area displays employing such devices.
Abstract:
This invention relates to methods and apparatus for displaying images holographically. A method of displaying an image holographically using a spatial lightmodulator (SLM), said SLM having a plurality of SLM pixels, the method comprising: displaying a diffraction pattern on said pixels of said SLM; and illuminating said pixels of said SLM such that light diffracted by said diffraction pattern on said SLM pixels comprises a content of said displayed image, a variation in brightness of said displayed image across said displayed image being modulated by an intensity envelope determined by the diffraction pattern of an individual said pixel, for example a sinc envelope; and wherein the method further comprises moving a peak or centre of gravity of said intensityenvelope away from a zero order spot and towards a centre of said displayed image by imposing a pattern of phase delay across said SLM pixels, said pattern of phase delay repeating at a spatial interval corresponding to a pixel interval of said SLM.