Patent application number | Description | Published |
20080226844 | Space-Variant Liquid Crystal Waveplate - The invention provides a space-variant liquid-crystal (LC) photo-aligned waveplate having a vortex optic axis pattern, and an apparatus and method for fabricating thereof. The method in it preferred embodiment includes exposing a substrate coated with a photo-alignable material such as LPP to linearly polarized UV radiation through a wedge-shaped aperture, while rotating two of the aperture, the substrate and the polarization of the UV light, so that an exposure area performs a full rotation about a center point on the substrate, at angular velocities selected so as to form a vortex alignment pattern of a pre-defined order. An LC material is then deposited on the substrate in direct contact with the photo-alignable material so that the LC director is aligned according to the photo-induced vortex alignment pattern. The method enables to fabricate vortex waveplate of any pre-defined vortex order. | 09-18-2008 |
20090009668 | Non-Etched Flat Polarization-Selective Diffractive Optical Elements - A polarization-selective diffractive optical element includes a liquid crystal polymer film supported by a substrate. The liquid crystal polymer film includes an array of pixels, each pixel encoded with a fixed liquid crystal director such that each liquid crystal director is aligned in a common plane perpendicular to the liquid crystal polymer film and provides a predetermined pattern of out-of-plane tilts. A size of the pixels in the array and the predetermined pattern are selected such that the liquid crystal polymer film forms a phase hologram for diffracting light polarized parallel to said common plane and a zeroth order diffraction grating for light polarized perpendicular to the said common plane. The non-etched and flat phase hologram is suitable for a wide range of applications. | 01-08-2009 |
20090122402 | Achromatic Converter Of A Spatial Distribution Of Polarization Of Light - An achromatic converter of spatial distribution of polarization from a first to a second pre-defined distribution of polarization is described. The converter comprises a plurality of photo-aligned quarter-wave or half-wave liquid crystal polymer layers, wherein the patterns of alignment of the layers are correlated with each other so as to make polarization conversion achromatic. Achromatic polarization vortices can be formed. The polarization conversion efficiencies over 97% have been demonstrated over most of the visible spectrum of light. The polarization converters can be used in imaging, photolithography, optical tweezers, micromachining, and other applications. | 05-14-2009 |
20090257106 | RETARDER-BASED DESPECKLE DEVICE FOR LASER ILLUMINATION SYSTEMS - A method and apparatus for reducing speckle in a laser illumination system uses a despeckle device including an optical retarder providing an odd integer multiple of substantially half-wave retardation for light emitted from a coherent laser in the laser illumination system. The near half-wave optical retarder has a substantially constant retardance and a spatially varied slow axis. The spatially varied slow axis imposes a phase mask on the beam of light, which provides sub-resolution optical phase modulation to a resolution spot on the detector. The near half-wave optical retarder is actuated mechanically or electrically to vary the sub-resolution optical phase modulation within an integration time of the detector. | 10-15-2009 |
20100066929 | OPTICAL VORTEX RETARDER MICRO-ARRAY - A micro-array of optical vortex retarders is provided by forming an alignment layer having a plurality of discrete alignment patches with different orientations. A layer of birefringent material, including one of a liquid crystal and a liquid crystal polymer precursor material, is provided adjacent to the alignment layer. The aligning orientation and position of each discrete alignment patch in the plurality of discrete alignment patches is selected to induce the layer of birefringent material to form at least one optical vortex retarder adjacent to a substantially non-oriented region of the alignment layer. | 03-18-2010 |
20110027494 | NON-ETCHED FLAT POLARIZATION-SELECTIVE DIFFRACTIVE OPTICAL ELEMENTS - A method of fabricating an optical element including a liquid crystal layer having a spatially-varying tilt angle includes coating a substrate with a linearly photopolymerizable polymer layer, irradiating the linearly photopolymerizable polymer layer with linearly polarized ultra-violet light at a oblique angle, and coating a layer of liquid crystal material on a surface of the irradiated linearly photopolymerizable polymer layer. The liquid crystal material has a predetermined relationship between its tilt angle and a total dose of the linearly polarized ultra-violet light. The linearly photopolymerizable polymer layer is irradiated with at least one dose of linearly polarized ultra-violet light that is sufficient to induce formation of a plurality of discrete regions within the liquid crystal layer having a larger in-plane birefringence than an adjacent or surrounding region. | 02-03-2011 |
20110032483 | MULTI-SEGMENT OPTICAL RETARDER FOR CREATING 3D IMAGES - A multi-segment optical retarder that can be used with or within a single projector for creating 3D images. The multi-segment optical retarder is coupled to an actuator used to effect some predetermined linear, rotary, or oscillating movement of the multi-segment optical retarder such that a fast axis orientation of each segment is substantially constant relative to itself over time and for a given area of incidence. | 02-10-2011 |