Abstract: A projection display apparatus 101 in which the light quantity adjusting means has a simple and readily interchangeable structure, and which can improve image quality by adjusting the quantity of light received by a light valve continuously, without causing illuminance irregularities, and without having unwanted light radiated onto the screen, the light quantity adjusting means 9 having light blocking members 91L, 91R for blocking light in transit to a second lens array 22, and rotational axes 91LA, 91RA for turnably supporting each of the light blocking members on an xy plane, the light blocking members 91L, 91R and rotational axes 91LA, 91RA being positioned so that the rotational axes 91LA, 91RA are disposed in positions symmetric with respect to the optical axis AX on the xy plane, and the turning range from the light blocking initiation position at which the light blocking members 91L, 91R, by being turned, start to block light in transit toward the second lens array 22 to the maximum light blocking posi

Abstract: A multiple path stereoscopic projection system is disclosed. The system comprises a polarizing splitting element configured to receive image light energy and split the image light energy received into a primary path and a secondary path, a reflector in the secondary path, and a polarization modulator or polarization modulator arrangement positioned in the primary path and configured to modulate the primary path of light energy. A polarization modulator may be included within the secondary path, a retarder may be used, and optional devices that may be successfully employed in the system include elements to substantially optically superimpose light energy transmission between paths and cleanup polarizers. The projection system can enhance the brightness of stereoscopic images perceived by a viewer. Static polarizer dual projection implementations free of polarization modulators are also provided.

Abstract: A touch screen device and method of displaying images using display windows and selecting execution menus displayed on the display windows in a touch screen device are provided. The touch screen device includes a screen, a display configured to display images thereon and a detector configured to detect a touch on the screen, and a controller configured to control operation of the touch screen device in accordance with the screen touch detected by the detector. The controller causes two or more display windows to be displayed in an overlapped manner. Further, if the touch is detected on an underlying display window covered by an overlying display window, the controller causes a display form to be changed in response to the touch. That is, if a touch is detected on the display window covered by the overlying display window, the touched display window is displayed as an overlying display window.

Abstract: An assembly for converting a microscope into a phase contrast microscope includes a first optical Fourier element that Fourier transforms light from a coherent light source, a cell in the Fourier plane arranged to receive light from the first optical Fourier element, a second optical Fourier element arranged to receive light from the cell and inversely Fourier transform the received light to provide an image, an image sensor that detects the image and generates an electronic representation of the image, and an adaptor capable of coupling the first and second Fourier elements, the cell, and the image sensor to the microscope such that the first Fourier element Fourier transforms light collected by the microscope objective.

Abstract: A process of producing an optical compensation sheet is provided, which comprises applying a solution comprising a liquid crystalline compound and a photo-polymerization initiator on a transparent support, drying the solution at a drying temperature which satisfies the following formula (1) to align the liquid crystalline compound, and then fixing the liquid crystalline compound by light irradiation to form an optical anisotropic layer: T?0.0014×Ecoh?65??(1) wherein T represents drying temperature (° C.), Ecoh represents condensation energy (J/mol) of the photo-polymerization initiator, by which an optical compensation sheet of stable optical characteristics can be obtained by using an essentially needed amount of photo-polymerization initiator for the photo-polymerization reaction. By the process of the present invention, the staining of the production facility of the optical compensation sheet derived from vaporization of photo-polymerization initiator can be reduced.

Abstract: 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.

Abstract: 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.

Abstract: A multiple path stereoscopic projection system is disclosed. The system comprises a polarizing splitting element configured to receive image light energy and split the image light energy received into a primary path and a secondary path, a reflector in the secondary path, and a polarization modulator or polarization modulator arrangement positioned in the primary path and configured to modulate the primary path of light energy. A polarization modulator may be included within the secondary path, a retarder may be used, and optional devices that may be successfully employed in the system include elements to substantially optically superimpose light energy transmission between paths and cleanup polarizers. The projection system can enhance the brightness of stereoscopic images perceived by a viewer. Static polarizer dual projection implementations free of polarization modulators are also provided.

Abstract: The present invention provides a retardation layer capable of effectively restraining the display quality deterioration without generating a bright and dark pattern in the display image even when a retardation layer is disposed in between a liquid crystal cell and a polarizing plate. The retardation layer comprises a plurality of minute units (domains) having molecular structure of cholesteric structure. Moreover, in the retardation layer, the helical pitch of the molecular structure is adjusted such that the selective reflected wavelength of the selected reflected light deriving from the molecular structure is shorter than the wavelength of the incident light on the retardation layer.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An optical modulator 100 includes an input unit 110, a splitter unit 120, a first waveguide 131, a second waveguide 132, a directional coupler unit 140, a first output unit 151, a second output unit 152, a first liquid-crystal cell 161, and a second liquid-crystal cell 162. The splitter unit 120, the first waveguide 131, the second waveguide 132, and the directional coupler unit 140 form an optical interferometer that branches an input light and causes the branched lights to interfere. The first liquid-crystal cell 161 and the second liquid-crystal cell 162 transmit the lights branched in the optical interferometer and delay the lights according to applied signals, respectively. The second liquid-crystal cell 162 is thinner than the first liquid-crystal cell 161.

Abstract: A variable retarder is inserted in one or more light channels of a kernel. The variable retarder is a nematic liquid crystal layer that is energized by an electric field and, for example, the voltage or frequency of the electric field dictates an amount of retardation effected by the variable retarder. The variable retarder either increases or decreases an optical path in which it is inserted relative to a reference. The amount of increase or decrease is utilized to place light paths in the kernel within acceptable tolerances. The acceptable tolerances are, for example, a tolerance of difference-light paths expected by a projection lens of device using the kernel for light modulation. In one embodiment, the variable retarder includes a polymer that can be used to fix a retardation value of the variable waveplate.

Abstract: 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.

Abstract: It is an object of the present invention to provide an optical waveform shaping device of high resolution. The above-mentioned problem is solved by an optical waveform shaping device (10) comprising a branching filter (1) for branching the light beam from a light source into light beams of each frequency, a condensing part (2) for condensing a plurality of light beams branched by the branching filter (1), a polarizing plate (3) for adjusting the polarization planes of the light beams having passed through the condensing part (2), and a spatial light modulator (4) having a phase modulation part and an intensity modulation part where the light beams having passed through the polarizing plate (3) are incident.

Abstract: It is an object of the present invention to provide an optical waveform shaping device of high resolution. The above-mentioned problem is solved by an optical waveform shaping device (10) comprising a branching filter (11) for dividing the light beam from a light source into light beams of each frequency, a condensing part (12) for condensing a plurality of light beams divided by the branching filter (11), a polarization separation means (13) for adjusting the polarizing planes of the light beams having passed through the condensing part (12), and a spatial light modulator (14) having a phase modulation part and an intensity modulation part where the light beams having passed through the polarizing plate (13) are incident.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed are digitally-switchable bandpass filters combining non-tunable retarder stacks with switchable liquid crystal cells. The disclosed filter embodiments function like a filter wheel with no moving parts that may provide faster switching, better image registration, compact size, and lower electrical power consumption. These benefits are attractive in portable handheld devices, such as bio-hazard sensors or glucose monitors.

Abstract: 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.

Abstract: An optical filter assembly having selectable bandwidth is presented. The optical filter assembly includes a first optical filter, a first optical retarder with optical retardance R1, a second optical retarder with optical retardance R2, a polarization switch positioned between the first and second retarders which causes their retardances to substantially add in a first switch setting and to substantially subtract in a second switch setting, and an exit polarizer. A multispectral imaging system using tunable optical filters having selectable bandwidth is presented. A method of filtering light is also presented. The method includes providing a first optical filter, providing a dynamic bandwidth stage including a polarization switch, selecting a first setting of the polarization switch, and producing a first filter action for light passing through the first filter and the dynamic bandwidth stage.

Abstract: A projection design configured for use with a projector having a projector lens is provided. The device includes at least one pi-cell or pi-cell electro-optical modulator in combination with a wire grid polarizer mounted proximate the pi-cell(s). The design may include a cleanup polarizer between the pi-cell(s) and the wire grid polarizer and optionally a protective window between the wire grid projector and projection lens. The device may be oriented at an angle substantially differing from the axis of the projector lens. The resultant device includes spacing for airflow and can offer improved performance, particularly in heating, over designs previously available.

Abstract: A birefringent optical filter and associated method are described which demonstrate improved performance for both fixed and tunable filter configurations. One exemplary embodiment involves an initial filter configuration, having an output polarizer, that exhibits an initial spectral filter response having an undesired transmission feature and a desired transmission feature. An additional polarizer follows the output polarizer and an adjustable retarder is disposed directly between the output polarizer and the additional polarizer to produce an overall spectral filter response that eliminates the undesired transmission feature, while passing the desired transmission feature. Another exemplary embodiment uses at least one reflective polarizer for passing light along the filter optical path, which light is characterized by a selected polarization, and for reflecting a rejected light that is characterized by a different polarization such that the rejected light is directed out of the optical path.

Abstract: A multiple depth display provided for displaying images at different depths comprises a single display device (61), for displaying all of the images. An optical system (62, 63, 64) is disposed in front of the display device (61). The optical system comprises first and second spaced-apart partial reflectors (62, 63) and polarization optics (64) for providing first and second light paths for first and second images or sequences of images displayed by the device (61). The first light path (65) comprises partial transmission through the first reflector (62), partial reflection from the second reflector (63), partial reflection from the first reflector (62), and partial transmission through the second reflector (65) towards a viewing region.

Abstract: 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 ?/2 plate disposed between two non-controllable ?/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.

Abstract: 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.

Abstract: A phase plate having a reduced size and a reduced weight and having accurately parted regions while it has the same function as a conventional two-parted optical rotation plate and an optical data recording/reproducing device capable of stably recording and reproducing are presented. A phase plate P1 comprising a polymer liquid crystal film 2 held between transparent substrates i, 4, wherein the polymer liquid crystal film 2 is parted spatially in the region into which an incident light enters, so that the light transmitting the phase plate assumes a different state of polarization depending on an aligning direction of the molecules of the polymer liquid crystal film 2. The phase plate is located as a two-parted optical rotation plate in an optical data recording/reproducing device.

Abstract: 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.

Abstract: 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.

Abstract: A switchable apochromatic polarization rotator is provided. A first fixed waveplate has a first principal axis fixed in a first orientation. A second fixed waveplate has a second principal axis fixed in a second orientation. First and second switchable waveplates have principal axes oriented such that broad spectral range electromagnetic radiation transmitted through all of the waveplates has a first rotated polarization, wherein, in response to one or more control signals applied to the switchable waveplates, the principal axes of the switchable waveplates rotate such that the electromagnetic radiation transmitted through all of the waveplates has a second rotated polarization. The switchable waveplates utilize ferroelectric liquid crystal material, nematic liquid crystal material, or be mechanically rotated to adjust for orientation of their principal axes. Utilizing waveplates as described may be used to tune for a desired spectral range and/or compensate for temperature dependencies.

Abstract: The present invention relates to a display device with a birefringent lens system having cylindrical lenses, extending in a main direction. The polarisation of light modulated by a LC layer is twisted by a rotator layer (25?) in order to be perpendicular or parallel with this main direction. A birefringent compensation layer (26) is used to remove any ellipticity introduced by the rotator layer (25?). This provides improved contrast when the display device is used e.g. in a switchable 2D/3D display.

Abstract: An athermalized birefringent filter for shifts in center wavelength and in bandwidth incorporates fixed retarder elements such as quartz or film retarders, along with electrically-variable retarder elements such as liquid crystal variable retarder cells. A control mechanism determines the amount of thermal drift in the fixed retarder element and produces an equal change in the variable retarder element. The sign of the change depends on whether the variable retarder element adds its retardance with that of the fixed retarder element, or opposes it. This change compensates for the thermal drift of the fixed retarder element. Further, the variable retarder element is constructed to provide the necessary range of retardance adjustment for spectral tuning and thermal compensation over a target thermal range. The control mechanism ensures that, for any specified wavelength, the birefringent filter operates in the same order over the full target thermal range.

Abstract: 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.

Abstract: A liquid crystal display comprising a first polarization film, a first retardation region, a second retardation region, a liquid crystal layer, a liquid crystal cell, and a second polarization film disposed in this order, liquid crystal molecules of the liquid crystal layer being aligned in parallel with surfaces of the substrates at the time of dark state, wherein Re of the first retardation region is 70 nm to 330 nm, Nz value of the first retardation region is greater than 0 and less than 0.

Abstract: The present invention provides a tunable terahertz (THz) wavelength selector device, which includes a fixed phase retarder, a tunable phase retarder and a pair of linear polarizers to form a unit. The fixed phase retarder and tunable phase retarder basically utilizes liquid crystals to provide phase retardation, moreover, utilizing birefringence phenomenon possessed by liquid crystals can provide adequate phase retardation. The fixed phase retarder utilizes horizontal orientation of liquid crystal cell to provide fixed phase retardation, while the tunable phase retarder however utilizes homeotropic liquid crystal cell and a rotatable magnet to provide a tunable phase retardation, wherein the tunable phase retarder can provide the positive or negative phase retardation relative to the fixed phase retarder, based on the direction of the magnet's rotating axes and totally use the entire tunable range into adjusting frequencies which can pass through.

Abstract: 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.

Abstract: The invention concerns an image display system comprising: a light source emitting an illuminating laser beam, a spatial light modulator controlled by control video signals corresponding to a succession of image frames; a matrix filter consisting of an array of different elementary color filters, illuminated by said illuminating beam and transmitting a spatially color-filtered beam to the spatial light modulator, an image of said filter being produced on an input surface of the spatial light modulator; means for displacing the filter image on the input of the spatial light modulator; and a control device for controlling at least one sequence of displacements of the filter image upon each image frame display.

Abstract: A polarization component, capable of efficiently reflecting an obliquely transmitted light beam toward a light source without degrading the transmission-polarization property of a perpendicular incident light beam, is provided. A C-plate having an oblique retardation of at least ?/8 with respect to a light beam inclined by at least 30° is disposed between at least two reflective circular polarizer layers whose selective reflection wavelength bands of polarized light overlapping each other. A combination of a reflective linear polarizer and a quarter wavelength plate may be used instead of the reflective circular polarizer. Alternatively, a combination of two reflective linear polarizer layers and two quarter wavelength plate layers (Nz?2) disposed therebetween can provide a similar effect. Further, a combination of two reflective linear polarizer layers and a half wavelength plate (Nz?1.5) disposed therebetween may be used.

Abstract: 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.

Abstract: The invention provides a light module (1) arranged to produce a beam of light (25) with a scattering pattern that is electrically variable. The module comprises a light source (2) arranged to provide a beam of light (5); and an electrically adjustable optical element (300) arranged to adjust the beam of light (5) from light source (2). The adjustable optical element comprises a first cell (10) with a first liquid crystal gel (11); optionally a polarization rotator (30); a second cell (20) with a second liquid crystal gel (21); and a unit 40 for applying a voltage across at least one of the first and second cells (10,20). Especially, the light module (1) provides a beam of light (25) with an anisotropic light distribution.

Abstract: An optical wavelength filter uses birefringence and polarization to discriminate and block a wavelength stop band. Birefringent elements, each having a fixed retarder and a liquid crystal, are placed along the signal path with the fast and slow axes in each pair being aligned and rotationally displaced from other pairs. The birefringence parts are arranged by their thickness, birefringence and progressive rotational orientation so that each pair contributes to achieving a specific polarization state for specific periodic wavelength discrimination bands. A selection polarizer at the output blocks bands that have this polarization state. The birefringence elements are tuned in a coordinated manner and thereby to select one or more wavelengths as the band stop discrimination band.

Abstract: A rotatory polarization plate capable of extracting an emission polarized light from an incident polarized light and rotating an azimuth angle of an polarization axis of the incident polarized light, wherein a rotatory polarization angle of the azimuth angle is changed by an incidence angle of the incident polarized light, is useful for an optical element capable of condensing and collimating incident light from a light source in a specific direction.

Abstract: A polarization controller includes a plurality of liquid crystal cells positioned as cladding on a waveguide that propagates a beam of light so that the evanescent field extends into the liquid crystal cells, and a ½-wave birefringent retarder for rotating the eigenstates of polarization between the liquid crystal cells. For fast response, the evanescent field preferably extends only into the surface effect region of the liquid crystal cells, where directors in the liquid crystal respond faster to changes in voltages applied across the liquid crystal cells.

Abstract: A liquid crystal optical performance monitor is described that employs a liquid crystal tunable filter for receiving a P-polarization beam and a rotated S-polarization beam from a C-polarizer. The rotated S-polarization beam from a birefringent crystal in C-polarizer propagates through a waveplate which rotates the polarization by 90 degrees, resulting in the rotated S-polarization beam having the same polarization orientation as the P-polarization beam. The liquid crystal tunable filter therefore receives just the P-polarization orientation. The C-polarizer and a small beam collimator are rotated so that the polarization orientation of the P-polarization beam and the rotated S-polarization beam matches the orientation of the LC inside the LC cavity of the LC tunable filter. In a first embodiment, the liquid crystal optical performance monitor is implemented with a photodiode. In a second embodiment, the liquid crystal optical performance monitor is implemented with a bi-cell photo diode.

Abstract: The present invention is directed to the provision of an optical pickup apparatus in which a liquid crystal optical element constructed by combining an aberration correcting liquid crystal panel and a ?/4 liquid crystal panel in an integral fashion is mounted in a tilted position. More particularly, the invention provides a liquid crystal optical element comprising a first liquid crystal layer for correcting aberration, a second liquid crystal layer functioning as an n?/4 plate and combined in an integral fashion with the first liquid crystal layer, a transparent electrode for generating a potential difference on the second liquid crystal layer in order to control an amount of phase difference for the light beam passing through the second liquid crystal layer, and a driver for driving the transparent electrode so as to generate a potential difference that is the lowest among a plurality of potential differences that cause the second liquid crystal layer to function as an n?/4 plate.

Abstract: The transparent electrode of the liquid crystal panel includes the first partial electrode portion constituted by the pattern electrodes and the second electron portion constituted by the pattern electrodes. When the central axis of the objective lens and the central axis of the liquid crystal panel are aligned with each other, the light beam passes through the first electrode portion. In this case, wavefront aberration is compensated by providing a predetermined phase difference to the light beam in the region of the liquid crystal corresponding to the first electrode portion. When the positions are not aligned and misalignment occurs, the light beam passes through the first electrode portion and the second electrode portion. In this case, wavefront aberration is compensated by providing a predetermined phase difference to the light beam in the region of the liquid crystal corresponding to the first electrode portion and the second electrode portion.

Abstract: The present application describes a retarder stack color switch using a single polarization analyzer for reflective-mode projection displays. The single polarization analyzer permits additive mode switching, which optimizes the chrominance of the additive primary outputs and the black state. Moreover, the single analyzer color switch provides a white state, which is frequently used in sequential systems. The single analyzer color switch overcomes some of the cost and manufacturing challenges associated with conventional transmissive full color switches based on retarder-stack-filters. The single analyzer color switch according to an embodiment uses a split-path so that relatively weak colors can follow a “high-efficiency” path.

Abstract: A liquid crystal optical attenuator is provided that is used to control the intensity of a light signal. The optical attenuator includes at least one polarizing element having an optical polarization axis, wherein the polarizing element transmits a portion of a light signal proportional to the angular difference between the optical polarization axis of the light signal and that of the polarizing element. The optical attenuator also comprises a variable liquid crystal rotator that includes a semi-transparent liquid crystal device, and a plurality of electrodes configured to conduct electricity to the liquid crystal device. The polarization axis of the light signal transmitted through the liquid crystal device will be rotated by an amount proportional to the magnitude of the electricity applied to the plurality of electrodes. In one embodiment, the optical attenuator is employed as part of a laser package that includes a laser, a pair of polarizing elements, and a faraday rotator.

Abstract: A liquid crystal variable wavelength filter unit and its driving method applicable for a Wavelength Division Multiplexing (WDM) communication system and an optical network using an optical fiber. The liquid crystal variable wavelength filter unit (130) includes a band pass filter (111) configured of a dielectric multi-layered film inclined by a predetermined angle of ? between a first liquid crystal beam deflector (101) and a second liquid crystal beam deflector (103) and held between a first wedge prism (121) and a second wedge prism (123). The first drive device (141) is connected to the first liquid crystal beam deflector (101), and the second drive device (143) is connected to the second liquid crystal beam deflector (103). The wavelength is selected by the liquid crystal beam deflector by making the outgoing angle variable with respect to the band pass filter.