Abstract: A multimodal imaging system comprises a light source, an image sensor comprising a plurality of pixels, and an optical filter comprising a first filter element and a second filter element. The light source emits partially coherent polarized light, and the first filter element and second filter element are arranged as an array parallel to the image sensor. The first filter element is configured for attenuated transmission of a first light spectrum, which comprises polarized light emitted by the light source, and the second filter element is configured for transmission of a second light spectrum. The image sensor is configured to simultaneously capture light impinging on the image sensor from both the first filter element and the second filter element. Each filter element of the optical filter is configured for transmission of light to a subset of the imager pixels.

Abstract: An active prism structure includes: an isotropic layer made of a photocurable isotropic polymer having a predetermined refractive index np and stacked on a substrate; and a birefringent layer made of a birefringent material having an ordinary refractive index no and an extraordinary refractive index ne and stacked on the isotropic layer, an interface between the isotropic layer and the birefringent layer is formed in a prism shape, and refractive index differences occurring at the interface between the isotropic layer and the birefringent layer are different according to a polarization direction of incident light. The active prism structure is configured such that the refractive index differences are different according to the polarization direction of the incident light, and thus, it is possible to change a refraction angle and refraction direction of the prism by controlling the polarization direction of the incident light.

Abstract: A tunable film apparatus is provided. The apparatus includes: a first and second layer, a linear polarizer disposed in front of the first layer, liquid crystal elements disposed between the first and second layer; and a tuner configured to cause temporal averaging of a light received through the linear polarizer.

Abstract: A liquid crystal phase shifter, a method for producing the same and a method for shifting phase of electromagnetic wave are provided. The liquid crystal phase shifter includes: a first base substrate and a second base substrate opposed to each other; a first liquid crystal modulation portion and a second liquid crystal modulation portion between the first base substrate and the second base substrate; a first electromagnetic wave transport layer between the first base substrate and the first liquid crystal modulation portion; and a second electromagnetic wave transport layer between the first base substrate and the second liquid crystal modulation portion. The first liquid crystal modulation portion is configured to modulate a phase of electromagnetic waves in a first frequency range and the second liquid crystal modulation portion is configured to modulate a phase of electromagnetic waves in a second frequency range different from the first frequency range.

Abstract: A device has a hyperspectral imaging sensor including a polarizing device to receive and polarize an incoming beam of light, a liquid crystal variable retarder adjacent the polarizing device to receive the polarized beam of light from the polarizing device and to change polarization of the light in a wavelength dependent manner, an output polarizer to receive the wavelength-dependent polarized light and to convert polarization state information of the light into a form detectable as light intensity, a voltage source connected to the liquid crystal device, and a controller to control voltages applied to the liquid crystal variable retarder; an image sensor synchronized with the controller to receive the light in a form detectable as light intensity as a function of retardance of the liquid crystal variable retarder and convert the light to an output signal, and a processor to transform the output signal into spectral information.

Abstract: A method of driving an optical modulation device includes applying a voltage to an upper electrode; forming a forward phase slope by applying a first driving signal to a lower electrode in a first area; forming a backward phase slope by applying a second driving signal different from the first driving signal to another lower electrode in a second area; forming an area without phase retardation by applying a third driving signal to two lower electrodes in a third area between the first area and the second area; and forming a flat phase slope by applying a fourth driving signal different from the first to third driving signals one lower electrode in a fourth area between the first area and the second area.

Abstract: An image display system is provided. The image display system includes a display device; a reflecting unit; a first polarizer disposed between the display device and the reflecting unit; and a second polarizer, wherein the reflecting unit is located between the first polarizer and the second polarizer; wherein a first angle from an absorption axis of the first polarizer to an absorption axis of the second polarizer in counterclockwise direction is between 0±10 degrees.

Abstract: A display apparatus includes a light source and a display panel. The light source emits a light. The display panel includes a first polarizing plate, a second polarizing plate, a third polarizing plate, and a shutter. The first polarizing plate receives the light provided from the light source and incident to a lower portion thereof and linearly polarizes the light incident thereto. The second polarizing plate is disposed on the first polarizing plate and circularly polarizes the light exiting through the first polarizing plate. The third polarizing plate is disposed on the second polarizing plate and linearly polarizes the light incident thereto. The shutter is disposed on the first polarizing plate and mechanically deforms in a thickness direction of the first polarizing plate in response to an electrical signal. The display apparatus displays a grayscale in accordance with mechanical deformation of the shutter.

Abstract: An anti-glare device comprising: a first electrode and a second electrode configured to be opposite to each other; an anti-glare layer provided between the first electrode and the second electrode; and a reflector layer provided on the second electrode, wherein the anti-glare layer comprises a plurality of deflection molecules, which are capable of switching between an ordered deflection and a disordered arrangement when different voltage differences are applied between the first electrode and the second electrode; and the reflector layer is configured to reflect a light passing through the first electrode and transmitting through the anti-glare layer. In the anti-glare device, the multi-stable liquid crystal molecules or the Bi-stable liquid crystal molecules have a property of ordered arrangement during power on and disordered arrangement during power off, whether or not performing anti-glare function can be automatically switched, and an automatic partition control may be realized as well.

Abstract: The present invention provides a polarizing plate comprising a substrate, a polarizing coating layer formed on one side of the substrate, a first adhesive layer formed on the polarizing coating layer, a first retardation coating layer formed on the first adhesive layer, a second adhesive layer formed on the first retardation coating layer, a second retardation coating layer formed on the second adhesive layer, and a soft layer formed on the second retardation coating layer, wherein, the soft layer has an amended toughness of 1,000 to 40,000 MPa·%. The polarizing plate according to the present invention has excellent bending resistance and thus can be effectively used for a flexible display.

Abstract: A tunable optical filter integrates the functions of wavelength tuning and power isolation of back reflection. The optical signal enters a Faraday rotator twice, and isolation is provided by two birefringent crystals, having their optical axes oriented at 45 degrees with respect to each other. The two birefringent crystals are on the same side of the Faraday rotator. The integration of an optical tunable filter and an isolator function into a single packaged component helps to reduce the size and complexity of optical amplifier systems, such as EDFAs and PDFAs, operating in the 1550 nm and 1310 nm transmission bands, respectively.

Abstract: A head mountable display (HMD) is operable to detect the HMD's overall motion relative to its current orientation, and to display extra image material so that the extra image material moves in the same general direction as real objects would be seen by the user to move if the user were not wearing the HMD.

Abstract: A solid state photonics circuit having a liquid crystal (LC) layer for beam steering. The LC layer can provide tuning of an array of waveguides by controlling the application of voltage to the liquid crystal. The application of voltage to the liquid crystal can be controlled to perform beam steering with the light signal based on different tuning in each of the waveguides of the array. The waveguides are disposed in a substrate having an oxide or other insulating layer with an opening. The opening in the oxide layer exposes a portion of a path of the array of waveguides. The waveguides are exposed to the liquid crystal through the oxide opening, which allows the voltage changes to the liquid crystal to tune the optical signals in the waveguides.

Abstract: The present invention relates to a device for regulating the passage of energy through a light-transmitting area, comprising a first polarization layer, a second polarization layer and a switching layer which is arranged between the two polarization layers and changes the polarization properties of polarized light as a function of temperature, where the two polarization layers are characterized by a suitable choice of their transmission in the transmission direction and their degree of polarization. The invention furthermore relates to a process for the production of the device according to the invention and to the use of the device for influencing light transmission and/or the passage of energy into an interior as a function of temperature.

Abstract: The present invention relates to a layer arrangement which changes the transmission of light depending on its temperature, where the layer arrangement has a first polarization layer, a switching layer which influences the polarization properties of light depending on the temperature, and a second polarization layer, as well as an additional NIR transmission-preventing layer.

Abstract: An optical shutter employed in an enhanced vision system includes a wavelength selective polarizing filter in optical association with a liquid crystal polarization modulator to rapidly switch between optical states to alternately transmit visible (VIS) radiation and near infrared (NIR) radiation. The wavelength selective polarizing filter imparts a polarization state to incident radiation and transmits polarized radiation within at least the visible wavelength region. The liquid crystal polarization modulator receives incident radiation for internal propagation through the modulator and responds to first and second values of an applied control signal to switch the internally propagating radiation to, respectively, first and second polarization states. The switching between first and second polarization states produces, in cooperation with the wavelength selective polarizing filter, optical shutter output VIS and NIR radiation.

Abstract: A display device includes a transparent display panel and an adjustable light valve. The transparent display panel and the adjustable light valve are disposed opposite to each other. The transparent display panel includes a plurality of pixels including active-matrix organic light-emitting diodes for generating an image. When the display device operates under a transparent display mode, the adjustable light valve is in a transparent status. When the display device operates under a high color saturation display mode, the adjustable light valve is in a non-transparent status. Thereby, the display device will not be limited to having only a display mode.

Abstract: The invention relates to a polarization rotator with small polarization ellipticity. The rotator includes a first optical unit (401) and a second optical unit (402) on a common optical axis. The first optical unit (401) is formed by a rectilinear polarizer (205) and a first quarter-wave plate (210), where the polarization direction of the polarizer is a bisector of the neutral axes of the quarter-wave plate. The second optical unit (402) is formed by a variable-delay plate (220) and a second quarter-wave plate (230), where the neutral axes of the second quarter-wave plate are bisectors of the neutral variable-delay plate axes.

Abstract: A wavelength selective switch device includes an incidence part where wavelength multiplexed light made of light of a plurality of wavelengths enters, an exit part that includes a plurality of fiber that outputs light of a wavelength selected from a signal in which wavelength multiplexed light that entered from the incidence part enters, a polarization diversity part that separates incidence light that entered the incidence part according to polarization components of the incidence light to make first and second optical beams, a wavelength dispersion and synthesis element that spatially disperses incidence light according to a wavelength of the incidence light and multiplexes the spatially dispersed reflected light according to the wavelength, and a wavelength dispersion and synthesis element that spatially disperses incidence light according to a wavelength of the incidence light and multiplexes the spatially dispersed reflected light according to the wavelength.

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: Thermochromic filters use combinations of absorptive, reflective, thermoabsorptive, and thermoreflective elements covering different portions of the solar spectrum, to achieve different levels of energy savings, throw, shading, visible light transmission, and comfort. Embodiments include stopband filters in the near-infrared spectrum.

Abstract: The invention relates to a polarisation rotator with small polarisation ellipticity. The rotator includes a first optical unit (401) and a second optical unit (402) on a common optical axis. The first optical unit (401) is formed by a rectilinear polariser (205) and a first quarter-wave plate (210), where the polarisation direction of the polariser is a bisector of the neutral axes of the quarter-wave plate. The second optical unit (402) is formed by a variable-delay plate (220) and a second quarter-wave plate (230), where the neutral axes of the second quarter-wave plate are bisectors of the neutral variable-delay plate axes.

Abstract: 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.

Abstract: A cholesteric liquid crystal device is provided. The cholesteric liquid crystal device includes a first substrate, a second substrate disposed opposite to the first substrate, a first reflective layer disposed over the first substrate, a second reflective layer disposed over the second substrate, facing the first reflective layer, and a partition structure disposed between the first and the second substrates, wherein a cavity is formed by the partition structure, the first reflective layer and the second reflective layer, and a cholesteric liquid crystal layer is filled in the cavity.

Abstract: 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.

Abstract: 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.

Abstract: Three dimensional projection systems may be single projector or multiple projector systems. These 3D projection systems may include a one or more polarization conversion systems (PCS). Each PCS may be designed for relatively small throw ratios and thus, may be designed to accommodate the small throw ratios. Each PCS may include a polarizing beam splitter, a first optical stack, a reflector and a second quarter wave retarder. The first optical stack may include a rotator, a polarizer, a polarization switch and a first quarter wave retarder. Each PCS may receive light from a respective projector, and the PBS in each PCS may direct the light toward the first optical stacks. The light may be converted to a different polarization state as it passes through the first optical stack. The converted light may then be re-directed by a reflecting element to a second quarter wave retarder. The second quarter wave retarder may convert linearly polarized light to circularly polarized light.

Abstract: 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.

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: A directional filter device for controlling direction of maximal blocking of incident light, including: (a) a front polarizer; (b) a plurality of front electrodes; (c) a liquid crystal layer having a front surface for receiving light and a back surface for emitting light; (d) a plurality of back electrodes; (e) a back polarizer; and (f) circuitry for applying a voltage between said front electrodes and said back electrodes, wherein said circuitry is configured to apply voltage between front and back electrodes that do not face each other using voltage sequences that create electric fields at angles selected from a range of angles, which are not perpendicular to the front surface of the liquid crystal layer.

Abstract: 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.

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: 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: Three dimensional projection systems may be single projector or multiple projector systems. These 3D projection systems may include a polarization conversion system (PCS). The PCS may be designed for relatively small throw ratios and thus, may be designed to accommodate the small throw ratios. The PCS may include a polarizing beam splitter, a first optical stack, a reflector and a second quarter wave retarder. The first optical stack may include a rotator, a polarizer, a polarization switch and a first quarter wave retarder. The PCS may receive light from a projector and the PBS may direct the light toward the first optical stack. The light may be converted to a different polarization state as it passes through the first optical stack. The converted light may then be re-directed by a reflecting element to the second quarter wave retarder. The second quarter wave retarder may convert linearly polarized light to circularly polarized light.

Abstract: 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.

Abstract: A liquid crystal spatial light modulator for adjusting an optical signal is configured in such a manner that a region of one element is partitioned into two regions so as to perform intensity modulation in one region and phase modulation in the other region. Since the region for performing the intensity modulation and the region for performing the phase modulation can be formed by partitioning one region of the liquid crystal spatial light modulator, only one element allows adjusting functions, both the optical signal intensity modulation and phase modulation.

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: 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.

Abstract: A controllable device for phase modulation of coherent light with modulator cells comprising liquid crystal molecules is provided which realizes 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: 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.

Abstract: The present invention provides an optical waveform shaping device (10) of high resolution 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: A variable optical device for controlling the propagation of light has a body of liquid crystal optical material with a center and a periphery, a heating system including an electrically controllable heat source and a thermal radiator arranged at the periphery for cooling a portion of the body of material. The heating system is operative to generate a spatially modulated temperature gradient and to provide a desired light propagation behavior.

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: 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: A projection type display device includes: a light emitting unit that includes at least one light source for emitting a coherent light. An image light generating unit modulates the light emitted by the light emitting unit to generate an image light. A projecting unit projects the image light. A phase modulating unit is arranged either between the light emitting unit and the image light generating unit or between the image light generating unit and the projecting unit and has an area where at least one of a retardation value and an azimuth direction of a slow axis is distributed respectively in different directions or values in a plane orthogonal to an optical axis.

Abstract: A liquid crystal spatial light modulator for adjusting an optical signal is configured in such a manner that a region of one element is partitioned into two regions so as to perform intensity modulation in one region and phase modulation in the other region. Since the region for performing the intensity modulation and the region for performing the phase modulation can be formed by partitioning one region of the liquid crystal spatial light modulator, only one element allows adjusting functions, both the optical signal intensity modulation and phase modulation.

Abstract: Imaging systems and methods for generating images of a sample wherein the system comprises an illumination source for illuminating the sample; an image viewing subsystem for capturing images from the sample; one or more liquid crystal panels and one or more birefringent elements, which are positioned between the sample and the image viewing subsystem, so that the images from the sample pass through the liquid crystal panels and the birefringent elements before reaching the image viewing subsystem; a device that changes one or more polarization states of the liquid crystal panels; and a controller that is configured to cause the device to change the polarization states of the liquid crystal panels.

Abstract: 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.

Abstract: The disclosure is directed to projectors, optical compensation methods and liquid crystal devices. In one example, a liquid crystal panel has a liquid crystal layer pinched between a pair of substrates. A pair of polarizing plates is disposed with the liquid crystal panel in between the polarizing plates. A first phase difference plate is disposed between the pair of polarizing plates for compensating for a phase difference of the liquid crystal panel. A second phase difference plate is disposed between the pair of polarizing plates for compensating for a phase difference of the pair of polarizing plates. In certain embodiments, the first phase difference plate may have an optically anisotropic layer having a negative refractive index anisotropy and an optical axis oriented in a thickness direction of the first phase difference plate. This abstract is intended only to aid those searching patents, and is not intended to be used to interpret or limit the scope or meaning of the claims in any manner.

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.