Abstract: An apparatus comprises a display panel having a back side and a front side. A mirrored surface receives sunlight and reflects the sunlight towards a lens system. The lens system focuses the reflected sunlight and directs the focused light towards the back side of the display panel to provide backlighting for the display panel. The backlighting enables the front side of the display panel to be viewed with improved contrast. Preferably, the display panel is of the liquid crystal display (LCD) type, and the mirrored surface is parabolic in shape.

Abstract: A light valve includes a light valve layer for forming an optical image as variations in its ability to scatter light, and two substrates between which the light valve layer is sandwiched and at least one of which is transparent. The light valve satisfies the following condition: ##EQU1## where t denotes a central thickness of the at least one of the substrates, n denotes a refractive index of the at least one of the substrates and d denotes a maximum diameter of an effective display area of the light valve layer. Alternatively, a transparent plate can be optically coupled to one of the substrates by a transparent body. In this case, the same condition is satisfied except that the thickness refers to a central thickness from a face of the transparent plate remote from the transparent body to the light valve layer.

Abstract: The invention relates to an electrooptical systemwhich between 2 electrode layers contains a liquid crystal mixture and a further optically transparent polymer medium, in which one of the electrode layers is in the form of an active matrix having nonlinear addressing elements integrated with the image point, while the other electrode layer forms the counter electrode,whose liquid crystal molecules have irregular orientation in the switched-off state,in which one of the refractive indices of the liquid crystal mixture is substantially the same as the refractive index of the medium n.sub.m and/or in which the quotient from the weight of the liquid crystal mixture and the weight of the optically transparent medium is 1.

Abstract: An optically addressed spatial light modulation system includes a ferroelectric liquid crystal spatial light modulator. A writing light source irradiates a writing light for recording an image onto the spatial light modulator. A read-out light source irradiates a bias light for adjusting the sensitivity of the spatial light modulator and a read-out light for reading a recorded image from the spatial light modulator. An adjusting circuit is used to adjust the bias light intensity or irradiation time in synchronism with the writing light to increase the sensitivity of the spatial light modulator. A driving circuit supplies writing voltage signals to the spatial light modulator. The irradiation times of the write light and the bias light overlap with the application of the writing voltage signals for a predetermined time for adjusting the sensitivity of the spatial light modulator.

Abstract: An apparatus for the generation of different given fringe-like light patterns in space is disclosed. The light patterns are predominantly used in optical metrology, for the three-dimensional acquisition of the shape of objects. Said light patterns are generated by astigmatic projection of a specially designed mask with sub-areas, the brightness of said sub-areas can be controlled, for example by implementing the mask as a liquid crystal light valve. The sub-areas are controlled in a way that by combination of bright and dark sub-areas, different sub-masks are formed. The astigmatic projection of any sub-mask generates one of the given fringe-like light patterns. In spite of the binary transparency of the sub-masks, continuously varying brightness can be achieved. All necessary sub-areas are located on the same area, interlaced such as in a mosaic work. On this area, any of the required sub-masks can be generated.

Abstract: A common path point diffraction interferometer uses dyed, parallel nematic liquid crystals which surround an optically transparent microsphere. Coherent, collimated and polarized light is focused on the microsphere at a diameter larger than that of the microsphere. A portion of the focused light passes through the microsphere to form a spherical wavefront reference beam and the rest of the light is attenuated by the dyed liquid crystals to form an object beam. The two beams form an interferogram which is imaged by a lens onto an electronic array sensor and into a computer which determines the wavefront of the object beam. The computer phase shifts the interferogram by stepping up an AC voltage applied across the liquid crystals without affecting the reference beam.

Abstract: An adaptive optics system which simultaneously measures the phase function and corrects the phase distortion of a wavefront using a liquid crystal device placed in an interferometer. The liquid crystal device inserts the conjugate phase function in the path and obtains a null in the interference pattern.

Abstract: A method and device for shaping both the temporal and spatial profiles of an input optical pulse to generate an output optical waveform are described. The method includes the step of dispersing the spectral frequencies of the input pulse. These frequencies are then focused with a cylindrical lens to form a two-dimensional optical field. The field is imaged on a mask featuring a two-dimensional array of pixels. The amplitudes, phases, or phases and amplitudes of the two-dimensional optical field are then filtered with the mask. The filtered spectral frequencies are then recombined to form the collective temporal profile of the output waveform. The two-dimensional optical field is then imaged in a sample plane to form the spatially coherent regions.

Abstract: An optical transmittance adjusting device which includes an optical transmittance adjusting plane divided into a plurality of areas; and adjusting means for detecting an amount of light incident on each of the areas and adjusting an optical transmittance separately for each of the areas based on the detected amount of light.

Abstract: An LCD projection system, located within a standard color CRT, is used to oject toward the screen decay stimulation patterns that vary dynamically from one frame to the next for each pixel based on the video signals received from external sources. This controls the output light intensity of the phosphors that are excited by a single electron gun. This system eliminates the three-electron-gun configuration of the standard CRT as well as the requirement of a shadow mask. What results is a CRT that is more rugged, easier to manufacture and that produces brighter and sharper images on its screen.

Abstract: An apparatus for selecting waveguide modes in optical fibers is disclosed, which comprises an optical fiber having of a core and a cladding sheathing the core. The optical fiber has a selected portion of the cladding removed and forms a recessed space in the cladding while preserving a predetermined thickness of the cladding remaining covering the core. The optical fiber is selected for allowing the transmission of light having multiple waveguide modes with radial and azimuthal electric field components. The apparatus further comprises a birefringent material filled in the recessed space. The birefringent material has the first and second refractive indices and the first refractive index is larger than the core index of the optical fiber, while the second refractive index is smaller than the cladding index of the optical fiber.