Abstract: The quality of images produced by confocal microscopy, and especially scanning laser confocal microscopy, is enhanced especially for images obtained in turbid mediums such as many biological tissue specimens, by reducing speckle from scatterers that exist outside (above and below) the focal plane region which is being imaged by utilizing sheared beams, both of which are focused to spots in the focal or image plane (region of interest) and polarizing the beams to have opposite senses of circular polarization (right and left handed circular polarization). The return light from the image plane of certain polarization is detected after passing through the confocal aperture of the confocal microscope. Light from scatterers outside the region of interest, which are illuminated by both of the sheared beams, interfere thereby reducing speckle due to such scatterers, and particularly scatters which are adjacent to the image plane. Sheared beams having orthogonal linear polarization, as may be obtained from a Wollaston or Nomarski prism are converted into circularly polarized beams of opposite polarization sense by a quarter wave plate. The optical signals representing reflections from the focal plane are derived by polarizing optics which may either, be a polarizing beamsplitter in the incident beam path or with a retarder and analyzer. The retarder may be selected to provide different polarization phase shift of the return light, and with the analyzer, detects the degree of elliptical polarization representing the optical activity and circular dichroism producing the optical signal representing the image.

Abstract: A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction. Further, the polarized lights, which have uniform brightness, can be emitted. Consequently, the polarization luminaire is suited to be a luminaire for use in a projection display that has liquid crystal light valves.

Abstract: The polarization properties of light backscattered from a two layer scattering medium are investigated. Linear, circular and elliptical polarization states are considered and it is demonstrated that the degree of polarization of the backscattered light is sensitive to the optical properties of both layers and to layer thickness. Furthermore, it is shown that the polarization memory of circularly polarized light enables deeper layers to be probed whereas linearly polarized light is more sensitive to surface layers. This has applications for characterizing burns and melanoma.

Abstract: A transflective LCD device improves a light transmittance in both the transmissive mode and the reflective mode and improves efficiency in the use of the light regardless of wavelength. To properly control the ON/OFF-switch of the blue wavelength band or the red wavelength band, the transflective LCD device adopts a half wave plate (λ/2) and changes the optic axes of the polarizers and the retardation film.

Abstract: An in-line optical fiber polarimeter comprises a plurality of fiber gratings and a single wave plate, disposed sequentially along a length of optical fiber. The fiber gratings are precisely oriented and have a predetermined grating period such that each grating functions to out-couple a predetermined portion of the optical signal passing through the polarimeter. A separate detector is associated with each grating to measure the out-coupled signal. The four Stokes parameters can be determined from the set of measurements and then used to determine to state of polarization of an optical signal passing through the polarimeter.

Abstract: Methods and apparatus for enhancing the performance of a reflective liquid crystal display system The high-contrast color splitting prism system utilizes a “double-passed” prism assembly Polarized light enters the prism assembly, is color-split and emitted as separate colors to spatial light modulators which reflect each color in accordance with a desired image The reflective light is passed, once again, through the prism assembly where the separate colors converge and propagate to a projection lens for display of the image on a screen A waveplate retarder is positioned between the liquid crystal display and the polarizing element The waveplate retarder is tilted with respect to the optical axis to eliminate the deleterious effects of the Fresnel reflections at the interfaces of the waveplate retarder

Abstract: A signal light from an optical transmission line propagates on a first optical fiber and enters a polarization converter. The polarization converter converts the input light with the given polarization into a linear polarization with a desired angle using two Faraday rotators and a quarter wave plate between them. The output light of the polarization converter propagates on a second optical fiber and enters a polarization beam splitter. The polarization beam splitter splits the light from the second optical fiber into two mutually orthogonal polarization components (e.g. TE and TM components) and outputs either of them (e.g. the TE component) toward a third optical fiber. A portion of the light propagating on the third optical fiber is split by an optical coupler and enters a photodetector. A bandpass filter (BPF) extracts a clock component of the signal from an output of the photodetector. A controller controls the polarization converter to adjust the polarization angle of the output light so as to maximize the output of the BPF according to the output of the BPF.

Abstract: The present invention provides an improvement in the separation mechanism to be used in a dense wavelength division multiplexer. The separation mechanism in accordance with the present invention includes an asymmetric pass band interferometer. The interferometer includes a first glass plate optically coupled to a second glass plate, forming a space therebetween; a first reflective coating with a first reflectivity residing inside the space and on the first glass plate; a second reflective coating with a second reflectivity residing inside the space and on the second glass plate; a first waveplate with a first optical retardance residing inside the space; and a second waveplate with a second optical retardance, optically coupled to the first glass plate and residing outside the space, where a combination of values for the first reflectivity, the first optical retardance, and the second optical retardance effect a separation of channels in at least one optical signal into at least two sets, and where the at least two sets have asymmetrically interleaved pass bands. The asymmetric pass band interferometer in accordance with the present invention is capable of separating channels from signals with different data transfer rates. With the present invention, a maximum use of available bandwidth on an optical fiber may be accomplished. An added functionality of the asymmetric pass band interferometer of the present invention is the ability to facilitate an asymmetric or uneven add/drop function while also separating the channels.

Abstract: Focal plane wideband infrared digital polarization imagery will be compared with visual wideband focal plane digital imagery of a camouflaged C-130 aircraft to show the extreme enhancement possible using digital imagery. The experimental observations will be compared with theoretical calculations and modeling results of both specular and shadowed areas. The relationship of both the specular and the shadowed areas to surface structure, orientation, specularity, roughness, shadowing, orientation and complex index of refraction will be illustrated. The imagery was obtained in four plane polarized directions with axes oriented vertically, horizontally and at plus and minus 45 degrees to the vertical. Nine locations on the aircraft were chosen (tail, fuselage, wing and propeller as well as five sky locations to establish sky background. Both sunlit and shadowed locations were examined. The direction of the dominant plane of polarization was obtained, but not the existence of circular polarization, which requires a quarter wave plate to resolve temporal coherence. Unpolarized radiation exists in the imagery,but its coherence is not evident without a phase resolving element.

Abstract: PROBLEM TO BE SOLVED: To provide a device for reducing speckles which can decrease the speckle pattern appearing on the illumination face to produce uniform illumination. SOLUTION: The laser light 1 with linearly polarized light having the polarization plane rotated by 45° is made incident on a first polarization beam splitter 4-1 to be separated into the P polarized light component and S polarized light component. The P polarized light component is transmitted while the S polarized light component is reflected to equally separate the both polarized light components. The P polarized light component directly propagates while the S polarized light component is reflected by a return prism 6-1 to produce an optical path difference longer than the coherence length from the optical path length of the P polarized light, and both components are separately made a second polarization beam splitter 5-1. Thus, incoherent laser light 1 having two kinds of polarized light components with the optical path difference longer than the coherence length is obtained as the output from the second polarization beam splitter 5-1. COPYRIGHT: (C)2001,JPO

Abstract: A display system, including: a light source providing illumination; a linear array of electromechanical grating devices of at least two individually operable devices receiving the illumination wherein a grating period is oriented at a predetermined angle with respect to an axis of the linear array wherein the angle is large enough to separate diffracted light beams prior to a projection lens system for projecting light onto a screen; a polarization sensitive element that passes diffracted light beams according to their polarization state; a segmented waveplate for altering the polarization state of a discrete number of selected diffracted light beams wherein the segmented waveplate is located between the linear array and the polarization sensitive element, a scanning element for moving the selectively passed diffracted light beams on the screen; and a controller for providing a data stream to the individually operable devices.

Abstract: An illumination system for a flat panel micro-display device includes a flat panel edge lit lightguide having a polarizing layer on a major surface and a polarization rotator and reflector proximate to an edge face of the lightguide. The polarization rotator changes the polarization state of light that is initially reflected from the polarization layer to a desired polarization state from an undesired polarization state and the reflector reflects the light back to the polarization layer. The rotated and reflected light propagating within the lightguide passes though the polarizing layer and illuminates a LCD panel of the micro-display. The combination of the polarization rotator and the reflector provide a controlled system in which most of the initially reflected light is utilized to illuminate the LCD panel. In an embodiment, the polarizing layer is a polarizing film that passes P polarized incoming light and reflects S polarized incoming light, the polarization rotator is a quarter wave plate that rotates light by a quarter wave, and the reflector is a mirror that reflects light without changing the polarization state of the light.

Abstract: An optical imaging assembly for imaging light from a display. The optical assembly is constructed from first and second linear polarization filters, first and second lenses that are preferably concave-convex lenses, and first and second ¼ wave plates. The first linear polarization filter passes light polarized in a first direction, and second linear polarization filter passes light polarized in a second direction that is orthogonal to the first direction. A folded imaging assembly is constructed from the first and second lenses and the first ¼ wave plate. The first and second lenses have partially reflecting coatings on one surface of each lens. The folded imaging assembly and the second ¼ wave plate are located between the first and second linear polarization filters. In the preferred embodiment of the present invention, the first ¼ wave plate has a birefringence axis that is orthogonal to the birefringence axis of the second ¼ wave plate and the two ¼ wave plates are constructed from the same material. The partially reflective coating of one of the first and second lenses preferably includes a material having a reflectivity that depends on the direction of linear polarization of light striking the reflective coating. The surfaces of the convex-concave lenses are preferably spherical. The lenses preferably provide a substantially telecentric optical imaging system.

Abstract: We report the appearance of circular birefringence (optical activity) in amorphous side-chain azobenzene polymer films on illumination with circularly polarized light. The effect is observed only if an optical axis is previously created in the film with the help of linearly polarized light. The photoinduced optical activity is believed to be due to changes in the polymer structure initiated by a circular momentum transfer from the circularly polarized light to the azobenzene chromophores.

Abstract: An imaging system, comprising a broadband unpolarized white light source (81), a polarization converter system for converting polarization axes of unpolarized white light into a substantially single polarization axis, to produce a beam of polarized light, a selective polarization filter (82), adapted to selectively rotate a polarization axis of a selected spectral band of light of the with respect to remaining polarized light based on a control signal (119), a polarized beam splitter (84), for separating light having a the substantially single polarization axis from light having a rotated polarization axis, a pair of electro-optic spatial light modulators (86, 89), disposed along a path of light within the spectral band and a path of remaining light outside the spectral band, respectively, and being adapted to modulate an image therein, and a polarized beam splitter (88), for recombining modulated light from the pair of light modulators. In a preferred embodiment, the selective polarization filter (82, 72) is divided into a plurality of regions (70, 71), each adapted to independently and selectively rotate a polarization axis of a selected spectral band of light of the with respect to remaining polarized light.

Abstract: An assembly for restricting the angle of vision of an image emitted from an LCD screen (10) comprising a linearly parallel arrangement of two polarizing films (22, 24) with at least two waveplates (30, 32) therebetween. The transmission planes of the polarizing films are at an angle, preferably 90° to each other. At least two parallel waveplates are positioned between the polarizing films. Each waveplate has parallel transmitting regions alternating between birefringent (36) and isotropic regions (34). The waveplates are positioned in a spaced apart relationship to each other such that substantially orthogonal light passing through the first polarizing screen and one of the birefringent or isotropic alternating transmitting regions of the first waveplate will pass through the other of the alternating striped transmitting regions of the second waveplate. Light so transmitted will then pass through the second polarizing film and be viewable. At least a portion of the horizontal components of non-orthogonal light incident on the waveplate assembly will not pass through the second polarizing film. This assembly results in an angle of vision narrower than from the LCD screen.

Abstract: A polarized component is obtained with a high conversion efficiency in a light guide which produces one of the polarized components by having it transmitted. The light from a light source is incident to a light guide which comprises a plurality of light guide layers and reflected by the end surface to an interface between the light guide layers. The polarized component transmitting through the end surface is rotated in its polarization plane by a wave length plate and reflected by a reflecting plate for reentrance to the light guide at the end surface of the light guide toward the interface. The reentering light mostly transmits through the interface because the polarization plane is rotated. A reflected light polarized component is returned to the wave length plate and the reflecting plate, and directed back to the interface again. The polarized component transmitting through the interface is similarly transmitted and reflected in the next interface. The number of interfaces can be reduced by increasing the reflection of the polarized component reflected in the interface. For this purpose, the index of refraction in the direction along the axis of the reflected polarized component is increased by making the index of refraction of the light guide layer anisotropic.

Abstract: A method and apparatus for multiplexing/de-multiplexing optical signals, comprising of a linear polarizer (450, fig. 4c), wave plates (452, fig. 4c), and a beam displacer/combiner (454, fig. 4c), wherein the wave plates (340, 342, 344, 346, fig. 4c) optically coupled to the linear polarizer (400, 402, 404, AB, fig. 4c), and the wave plates rotate both odd and even channel components of an optical beam between a linear and an orthogonal relationship depending on the propagation direction, and each of wave plate is of a selected length and index of refraction which together determine a free spectral range which corrresponds to a spacing between adjacent gridlines of a selected wavelength grid, and each of the wave plates is tuned to even symmetry with the selected wavelength grid and wherein the beam displacer/combiner (420, AB, 422 AB, 426, 428, FIG. 4c) displaces and combines orthogonally polarized odd and even channel components of an optical beam depending on a propagation direction.

Abstract: The touch-panel equipped liquid crystal display apparatus has a polarizing plate, a ¼ wave plate, a touch panel, a ¼ wave plate, and a liquid crystal cell, which are disposed in the above-mentioned order from the display surface side. The arrangement is made such that the polarization axis of the polarizing plate and the slow axis within the film surface of the ¼ wave plate make an angle of 45° substantially, and the slow axis within the film surface of the ¼ wave plate and the polarization axis of the emission light from the liquid crystal cell make an angle of 45° substantially. Further, the slow axes of the ¼ wave plates and are arranged not in parallel with each other, or not cross over at right angles.

Abstract: A reduced minimum configuration (RMC) fiber optic current sensor (FOCS) is proposed which includes a sensing coil or sensing region, a light source and an optical path arranged between the front output of the light source and the fiber optic sensing coil/region. At least one quarter wave plate is disposed between the optical path and the sensing coil/region for converting linearly polarized light beams into circularly polarized light beams propagating through the sensing coil/region. The circularly polarized light beams propagating though the sensing region experience a differential phase shift caused by a magnetic field or current flowing in a conductor proximate to the sensing coil. A light detector is located at the back output of the light source and produces an output signal in response to return light intensity transmitted through the light source. The return light intensity is a measure of the magnetic field in the sensor coil/region. The magnetic field may be produced by an electric current flowing through a wire, wherein the sensor coil can be wound around the wire. Electronics is described which minimizes effects caused by changes in the environmental conditions.

Abstract: A polarization-mode-dispersion emulator in accordance with the principles of the present invention includes a plurality of PMD-generating stages aligned in cascade so as to form a clear light-path through the stage concatenation. Each PMD-generating stage includes an optical birefringent crystal or crystals for the purpose of imparting differential group delay and a polarization-rotating plate such as a half-wave waveplate for the purpose of imparting state-of-polarization rotation from one PMD-generating stage to the next. The polarization-rotating plates are mounted to rotation apparatuses and a controller coordinates the relative rotation of each waveplate for the purpose of generating PMD in a controlled manner.

Abstract: A polarization conversion system comprises a polarized light selective reflector that divides incident unpolarized light into first and second types of polarized light, transmits the first type of polarized light and reflects the second type of polarized light, a relay optical system that relays an incident light beam onto the polarized light selective reflector, a polarized light reflector, disposed on an optical path of a reflected light beam reflected by the polarized light selective reflector, that reflect the reflected light beam back to the polarized light selective reflector while converting the second type of polarized light to polarized light of the first type.

Abstract: An apparatus for scanning an object comprising a liquid crystal display; a light source optically coupled to said liquid crystal display; a beam splitter optically coupled to said liquid crystal display; an optical microscope optically coupled to said beam splitter; and a quarter wave plate optically coupled to said optical microscope, said quarter wave plate being for transforming linearly polarized light into circularly polarized light.

Abstract: An optical film is disclosed which is reduced in diffuse reflection while retaining anisotropy in the scattering of a linearly polarized light and is practically usable in a light diffuser film or viewing-side polarizing film for liquid crystal displays and the like. The optical film comprises a light-transmitting resin and dispersedly contained therein minute regions differing from the light-transmitting resin in birefringent characteristics, wherein the difference in refractive index between the minute regions and the light-transmitting resin in a direction perpendicular to the axis direction in which a linearly polarized light has a maximum transmittance, Δn 1 , is from 0.03 to 0.5 and that in the maximum-transmittance axis direction, Δn 2 , is smaller than 0.03, and the diffuse reflectance of linearly polarized light in the Δn 1 direction is lower than 30%. Also disclosed are: an optical element comprising two or more layers of the optical film, wherein the layers are superposed such that the Δn 1 directions for any of the layers are parallel to those for the adjacent layers; and an optical element comprising a multilayer structure which comprises at least one of a polarizing film, retardation film, transparent resin plate, and reflecting layer and one or more layers of the optical film.

Abstract: PROBLEM TO BE SOLVED: To provide an optical element capable of forming a surface light source device, which hardly cause degradation of performance of damage to a shape due to adhesion to adjacent members, has excellent workability is handling and emits light with excellent forward directivity, and an LCD device excellent luminance. SOLUTION: The optical element comprises cholesteric liquid crystal layers (1, 2) with Grandjean orientation which are mutually laminated, in combination of the selective reflection wavelength regions of circularly polarized light common to each other and with the left- or right-handed polarization of the circularly polarized light reversed by the selective reflection, or in combination of the selective reflection wavelength regions common to each other and with the left- or right-handed polarization of the circularly polarized light unchanged by the selective reflection via a half-wave plate. The surface light source device comprises the optical element arranged on a sidelight type or a direct lower type surface light source provided with a fluorescent lamp composed of a tube with three wavelengths as a light source. The optical element forms the LCD device. In the optical element and the devices, the light in a specified wavelength region transmitting through the first cholesteric liquid crystal layer is selectively reflected and shielded by the second cholesteric liquid crystal layer. COPYRIGHT: (C)2002,JPO

Abstract: A liquid crystal panel has a cholesteric filter and the quarter wave plate inserted between a glass substrate and color filter elements, and each section of the cholesteric filter reflects either right-handed or left-handed circularly polarized light component recognized as one of the three primary colors and the circularly polarized light components recognized as other primary colors toward a light source so as to recycle these circularly polarized light components, thereby enhancing the utilization factor of incident light without increase of power consumption.