Class / Patent application number | Description | Number of patent applications / Date published |
349018000 | Variable or rotatable retarder used with other retarders to produce filtering effects (Solc, Lyot, Partial) | 30 |
20080198279 | Electro-Optical Filter - The present invention provides an electro-optical filter for filtering light from an object. The filter is arranged for receiving the light via a first imaging element and comprises a plurality of reflective elements for receiving and reflecting the light. Each reflective element has an optical property that is dependent on an intensity of the light at or near the reflective element. The optical property controls local filtering of the light intensity in a manner such that, above a predetermined intensity threshold, the filter reduces intensity differences of light originating from bright and dark regions of the object. | 08-21-2008 |
20080198280 | Light Module for Producing Light With a Scattering Pattern that is Electrically Variable and Use thereof as Multiple Purpose Light - The invention provides a light module ( | 08-21-2008 |
20090021657 | Viewing angle controllable liquid crystal display - One embodiment of the invention includes an LCD which comprises a back light module, a first polarizer, a second polarizer, an LCD panel, a first viewing angle controller and a third polarizer. The first polarizer and the second polarizer are disposed on the back light module and respectively have a first transparent axis and a second transparent axis which are perpendicular to each other. The LCD panel is disposed between the first polarizer and the second polarizer. The first viewing angle controller is disposed between the LCD panel and the second polarizer and has a first horizontal alignment liquid crystal layer. The third polarizer is disposed between the LCD panel and the first viewing angle controller and has a third transparent axis parallel to the second transparent axis. | 01-22-2009 |
20090073331 | TUNABLE LIQUID CRYSTAL DEVICES, DEVICES USING SAME, AND METHODS OF MAKING AND USING SAME - An electro-optical device comprises a liquid crystal material disposed in a cell and electrodes configured to bias the liquid crystal material into a generally in-plane director configuration having a non-constant spatial pattern selectable or adjustable by an in-plane component of the biasing to produce a desired refractive of diffractive optical effect. | 03-19-2009 |
20090167970 | Flexoelectro-optic liquid crystal device - A device for controlling the polarization state of transmitted light comprises first and second cell walls enclosing a layer of a chiral liquid crystal material. The material has a uniformly orientated helical axis in the absence of an applied field, and electrodes for applying an electric field substantially normal to the helical axis. An applied electric field flexoelectrically couples to the molecules, causing distortion of the helical structure and hence changes the bulk birefringence of the cell. | 07-02-2009 |
20090167971 | THERMALLY SWITCHED ABSORPTIVE WINDOW SHUTTER - The thermally switched absorptive optical shutter may be a self-regulating “switchable absorber” device that may absorb approximately 100% of incoming light above a threshold temperature, and may absorb approximately 50% of incoming light below a threshold temperature. The shutter may be formed by placing a thermotropic depolarizer between two absorptive polarizers. This control over the flow of radiant energy may occur independently of the thermal conductivity or insulation of the shutter device and may or may not preserve the image and color properties of incoming visible light. This has energy-efficiency implications as it can be used to regulate the internal temperature and illumination of buildings, vehicles, and other structures without the need for an external power supply or operator signals. It also has aesthetic implications since the shutter device has unique optical properties that are not found in traditional windows, skylights, stained glass, light fixtures, glass blocks, bricks, or walls. Additionally, the shutter device may have application as a building material. | 07-02-2009 |
20090195715 | FLAT TOP TUNABLE FILTER WITH INTEGRATED DETECTOR - A free space tunable filter produces a passband output as a result of sequential processing by an array of narrowband tunable filters (NBTFs) each tuned to a slIghtly different frequency. The present invention is comprised of one or more stages having multiple interleaved sectors and comprising an array of NBTFs having a masked outer surface reflective coating. Stages cascading is used to increase the device figure of merit and single stages are partitioned into multiple sectors that process a specific interleaved region of the bandwidth. Final stage output group passband signals are combined in a multiplexer and tapped with a partially transparent photodetector. | 08-06-2009 |
20090284671 | CONTROLLABLE DEVICE FOR PHASE MODULATION - A controllable device for phase modulation of coherent light with modulator cells comprising liquid crystal molecules is provided which realises a large number of phase steps per modulator cell and whose switching delay is shorter than 1 ms. The device can include a spatial light modulator with a modulator matrix having regularly arranged controllable LC modulator cells, a light source which illuminates the modulator matrix, and control means for controlling the phase modulation in the LC modulator cells. The modulator matrix can be configured to comprise a controllable λ/2 plate disposed between two non-controllable λ/4 plates; the controllable LC modulator cells can be PSS liquid crystal; each LC modulator cell is controllable locally with a positive or negative voltage value, depending on the actual phase values to be written; and the control means generate a globally constant phase offset for the phase values to be written in every other frame. | 11-19-2009 |
20090290079 | DISPLAY, INSTRUMENT PANEL, OPTICAL SYSTEM AND OPTICAL INSTRUMENT - A multiple depth display provided for displaying images at different depths comprises a single display device ( | 11-26-2009 |
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 |
20100103335 | POLARIZATION SELECTIVE SCATTERING SECURITY DEVICE AND METHOD FOR MANUFACTURING THE SAME - A polarization selective scattering security device comprising a printed patterned birefringent matrix of LCP polymer comprising a dispersed phase and optionally one or more additives, wherein the ordinary or the extra-ordinary refractive index of the birefringent matrix of LCP polymer is approximately matched by one of the indices of refraction of the dispersed phase aligned in the same direction whereas the other refractive index is not matched. Moreover, a process for producing such security device is disclosed. | 04-29-2010 |
20100118219 | Phase-Modulating Light Modulator and Method for Ensuring a Minimal Amplitude Modulation in Phase-Modulating Light Modulators - The invention relates to a phase-modulating light modulator and to a method for ensuring a minimal amplitude modulation in phase-modulating light modulators, wherein the phase-modulating light modulator comprises an optically active layer with at least one optically active volume region and with boundary surfaces, wherein the optically active layer is assigned at least one transparent compensation volume region which comprises at least one birefringent material with fixed refractive index ellipsoids, and has a polarizer arranged on the output side. An object is to achieve a reduced angle-dependence of the averaged amplitude modulation in the observation angle region. The object is achieved by optimizing the orientation with respect to one another of the refractive index ellipsoids of the optically active layer and of the compensation layers in a simulative manner. | 05-13-2010 |
20100141857 | OPTICAL WAVEFORM SHAPING DEVICE - It is an object of the present invention to provide an optical waveform shaping device of high resolution. | 06-10-2010 |
20100157179 | OPTICAL WAVEFORM SHAPING DEVICE - It is an object of the present invention to provide an optical waveform shaping device of high resolution. | 06-24-2010 |
20100177255 | METHODS SYSTEMS AND DEVICES FOR UTILIZING DIRECTIONS OF LIGHT RAYS - The present invention provides a multi layer directional filter comprising (a) a front polarizer, (b) a front glass plate provided with a plurality of transparent, individually addressable upper electrodes and addressing lines, said front glass plate being disposed behind said front polarizer, (c) a front transparent insulating layer, said front transparent insulating layer being disposed behind said front glass plate, (d) a middle liquid crystal layer containing liquid crystal molecules, (e) a hind transparent insulating layer, said hind transparent insulating layer being disposed behind said middle liquid crystal layer, (f) a hind glass plate provided with a plurality of transparent, individually addressable lower electrodes and addressing lines, (g) a hind polarizer, said hind polarizer being disposed behind said hind glass plate, and, (h) control circuitry adapted to provide sequences of voltage patterns to said electrodes of said front glass plate and said hind glass plate. | 07-15-2010 |
20100231817 | PHASE MODULATOR AND OPTICAL MODULATION DEVICE - An optical modulator | 09-16-2010 |
20100277658 | LIQUID CRYSTAL OPTICAL SWITCH CONFIGURED TO REDUCE POLARIZATION DEPENDENT LOSS - An optical device has the structure to perform switching and attenuation of an optical beam with reduced polarization dependent loss (PDL). The optical device includes a birefringent displacer and two liquid crystal (LC) structures. The first LC structure is used to condition s-polarized components of the optical beam and the second LC structure is used to condition p-polarized components of the optical beam. Each LC structure has a separate control electrode so that the s-polarized components of the optical beam and the p-polarized components of the optical beam can be conditioned differently and in such a manner that reduces PDL. The optical device may be configured for processing multiple input light beams, such as the multiple wavelength channels de-multiplexed from a wavelength division multiplexed (WDM) optical signal. | 11-04-2010 |
20100302469 | LIQUID CRYSTAL OPTICAL DEVICE CONFIGURED TO REDUCE POLARIZATION DEPENDENT LOSS AND POLARIZATION MODE DISPERSION - An LC-based optical device compensates for differences in optical path lengths of polarization components of input beam. As a result, PDL and PMD of the optical device are reduced. The compensation mechanism may be a glass plate that is disposed in an optical path of a polarization component so that the optical path length of that polarization component can be made substantially equal to the optical path length of the other polarization component that traverses through a half-wave plate. Another compensation mechanism is a birefringent displacer that has two sections sandwiching a half-wave plate, wherein the two sections are of different widths and the planar front surface of the birefringent displacer can be positioned to be non-orthogonal with respect to the incident input light beam. | 12-02-2010 |
20100315567 | LIQUID CRYSTAL BASED BROADBAND FILTER FOR FAST POLARIZATION IMAGING - A liquid crystal based broadband filter and imaging system for analyzing the polarization state of radiation. The filter includes four elements: a quarter wave plate; a 45° polarization rotator; a 90° polarization rotator; and a fixed polarizer. The first three of these elements are electronically switchable, allowing the user to select from any of the six possible polarization states. The switchable elements use multiple liquid crystal cells made from dual-frequency materials. A dual-frequency signal is used to activate and deactivate the various elements to achieve the desired state configuration. The dual-frequency signal drives the liquid crystal cells in and out of states, improving the overall switching time of the filter. The configuration of the liquid crystal cells within each of the filter allows broadband operation over most of the visible, infrared and ultraviolet spectra. The filter cycles through six configurations corresponding to the six polarization states of the incident radiation. Thus, the polarization state of the radiation can be completely characterized using the four Stokes parameters. Information related to the intensity and polarization of the radiation can be stored, displayed and analyzed. | 12-16-2010 |
20110001895 | DRIVING MECHANISM FOR LIQUID CRYSTAL BASED OPTICAL DEVICE - An optical device with liquid crystal (LC) cells for conditioning the polarization of incident light includes a drive unit for the LC cells that employs a digital technique. According to this digital technique, the drive unit generates control signals for opposing electrodes of the LC cells based on digital signals that have the same period but differ in phase by up to one-half period. By employing digital signals that differ in phase by up to one-half period with high resolution, the differential voltage across the LC cells can be controlled precisely to a desired RMS value. | 01-06-2011 |
20110007232 | POLARIZATION CONTROL SYSTEMS AND METHODS WITH ENDLESS POLARIZATION TRACKING USING A DITHERING ALGORITHM - The present disclosure includes a configuration of a polarization control system and an algorithm that realize fast polarization controlling and tracking while avoiding the Glitch problems (i.e., loss of polarization tracking). The polarization controller includes multiple stages along with tunable orientation and retardation angles. The retardation angles are initialized to at least two different values for better polarization tracking in normal mode. In a normal mode, only the orientation angles of the polarization controller are dithered. When the monitored error is higher than the threshold, the polarization controller enters a glitch mode, and Glitch detection can be improved through error signal data processing. In the Glitch mode, at least one retardation angle is dithered along with the orientation angles. After the Glitch problem is avoided, the polarization controller stops dither the retardation angles and move all wave plates back to their initial values, and the polarization controller enters the normal mode. | 01-13-2011 |
20110279744 | Short wave infrared multi-conjugate liquid crystal tunable filter - A SWIR hyperspectral imaging filter has serial stages along an optical signal path with angularly distributed birefringent retarders and polarizers. The retarders can include active retarders such as tunable liquid crystal birefringent elements, passive retarders such as fixed retarders, and/or combinations thereof. Distinctly different periodic transmission spectra are provided by different filter stages, each having multiple retarders, in particular with some stages having broad bandpass peaks at wide spectral spacing and other stages have very narrow closely spaced peaks. The respective spectra include at least one tunably selectable band at which the transmission spectra of the filter stages coincide, whereby the salutary narrow bandpass and wide spectral spacing ranges of different stages apply together, resulting in a high finesse wavelength filter suitable for spectral imaging. The filter may be configured to provide faster switching speed and increased angle of acceptance and may operate in the rage of approximately 850-1700 nm. | 11-17-2011 |
20120169950 | Variable Transmission Window - The various embodiments include variable optical transmission devices with uniform or patterned polarizers or wave retarders configured to provide continuous or nearly continuous variations in light transmission based on linear translation. For example, embodiments include a variable transmission window including a first uniform polarizer with a first polarization axis, a second uniform polarizer with a second polarization axis, a first patterned wave retarder positioned between the first and second polarizers and including a first plurality of domains configured to vary in at least one of optic axis, thickness, or birefringence, and a second patterned wave retarder positioned between the first and second polarizers and including a second plurality of domains configured to vary in at least one of optic axis, thickness, or birefringence. The first or second wave retarder is configured to be linearly translatable relative to the other wave retarder. | 07-05-2012 |
20120257130 | Tunable Wavelength Filter - A wavelength filter based on a symmetric PLC circuit comprising an MZ filter-based demultiplexer, a waveguide resonator, and an MZ filter-based multiplexer is presented. The wavelength filter is tuned using pulse width modulated drive signals that enable fine wavelength control resolution. Embodiments in accordance with the present invention attain narrow spectral filtering capability over a wide wavelength tuning range. Further, embodiments in accordance with the present invention mitigate chromatic dispersion. | 10-11-2012 |
20120300143 | VIS-SNIR multi-conjugate liquid crystal tunable filter - A VIS-NIR hyperspectral imaging filter has serial stages along an optical signal path with angularly distributed birefringent retarders and polarizers. The retarders can include active retarders such as tunable liquid crystal birefringent elements, passive retarders such as fixed retarders, and/or combinations thereof. Distinctly different periodic transmission spectra are provided by different filter stages, each having multiple retarders, in particular with some stages having broad bandpass peaks at wide spectral spacing and other stages have very narrow closely spaced peaks. The respective spectra include at least one tunably selectable band at which the transmission spectra of the filter stages coincide, whereby the salutary narrow bandpass and wide spectral spacing ranges of different stages apply together, resulting in a high finesse wavelength filter suitable for spectral imaging. The filter may be configured to provide faster switching speed and increased angle of acceptance and may operate in the rage of approximately 400-1100 nm. | 11-29-2012 |
20140055695 | VARIABLE OPTICAL RETARDER - A sub-wavelength grating is placed inside a liquid crystal variable optical retarder to reduce polarization dependence of the optical retardation generated by the variable optical retarder. A small thickness of the sub-wavelength grating, as compared to a conventional waveplate, reduces the driving voltage penalty due to the in-cell placement of the sub-wavelength grating. | 02-27-2014 |
20140098309 | Short-Wavelength Infrared (SWIR) Multi-Conjugate Liquid Crystal Tunable Filter - A SWIR hyperspectral imaging filter has serial stages along an optical signal path with angularly distributed birefringent retarders and polarizers. The retarders can include active retarders such as tunable liquid crystal birefringent elements, passive retarders such as fixed retarders, and/or combinations thereof. Distinctly different periodic transmission spectra are provided by different filter stages, each having multiple retarders, in particular with some stages having broad bandpass peaks at wide spectral spacing and other stages have very narrow closely spaced peaks. The respective spectra include at least one tunably selectable band at which the transmission spectra of the filter stages coincide, whereby the salutary narrow bandpass and wide spectral spacing ranges of different stages apply together, resulting in a high finesse wavelength filter suitable for spectral imaging. The filter may be configured to provide faster switching speed and increased angle of acceptance and may operate in the rage of approximately 850-1700 nm. | 04-10-2014 |
20140168550 | POLARISATION ROTATOR WITH SMALL INDUCED ELLIPTICITY - The invention relates to a polarisation rotator with small polarisation ellipticity. The rotator includes a first optical unit ( | 06-19-2014 |
20160048049 | TUNABLE ACHROMATIC WAVEPLATES - The invention is a tunable achromatic wave plate comprised of two or more retarders made of electrooptic or magnetooptic materials arranged at different orientations with respect to each other and at least one voltage source configured to tune the retardation dispersion of each of the retarders by applying an external electric or magnetic field to each retarder separately. Also described are examples of optical systems in which the invention can be employed. | 02-18-2016 |
20160070113 | VARIABLE FOCAL BACKLIGHTING - A backlight unit includes a waveguide assembly having a first wedge and a birefringent wedge disposed adjacent to, and arranged nose-to-tail with, the first wedge, to define an interface of the waveguide assembly. The birefringent wedge has different indices of refraction for light propagating through the waveguide assembly in first and second polarization states. The first wedge is configured to propagate the light in the second polarization state at a different speed than the birefringent wedge. A liquid crystal layer is configured to selectively switch the light between the first and second polarization states. An extraction grating is configured to extract the light from the waveguide assembly at an emission angle established in accordance with an angle of incidence of the light on the extraction grating determined by an extent to which the light encountered the interface while propagating through the waveguide assembly in the second polarization state. | 03-10-2016 |