Abstract: A tunable filter is provided.

Abstract: Provided is a resonant reflective filter including a substrate and a grating layer, wherein the substrate is formed of a material having a lower reflective index than that of a material forming the grating layer. Thus, the resonant reflective filter can form a resonant spectrum having good symmetry and a sharp shape. Accordingly, the resonant reflective filter can have improved sensitivity and can be applied to optical systems that require a small linewidth.

Abstract: The present invention discloses a method for manufacturing a zero-order diffractive filter comprising a high-index material having an upper surface and a lower surface. The high-index material is positioned between a first low-index matter and a second low-index matter; the lower surface is adjacent to said first low-index matter and the upper surface is adjacent to the second low-index matter. Moreover, the high-index material has an index of refraction that is higher than the index of refraction of both said first low-index matter and said second low-index matter. The method comprises at least the following procedure: selectively providing, by employing at least one wet-coating technique, at least one of the following at least partially: the high-index material onto said first low-index matter.

Abstract: Color separation gratings, color separation microlenses and imaging arrays are provided. A color separation grating includes a transparent grating material having a grating formed therein. The transparent grating material has a first surface configured to receive incident light and a second surface opposite the first surface. The second surface is configured to pass selective separated colors from the incident light corresponding to different diffraction orders. The grating is formed in the first surface and includes a number of steps in a grating period and a number of sub-steps formed on each step. A combination of the number of steps and the number of sub-steps are selected to correspond to a number of diffraction orders produced by the color separation grating.

Abstract: A zoned order sorting filter for a spectrometer in a semiconductor metrology system is disclosed with reduced light dispersion at the zone joints. The order sorting filter comprises optically-transparent layers deposited underneath, or on top of thin-film filter stacks of the order sorting filter zones, wherein the thicknesses of the optically-transparent layers are adjusted such that the total optical lengths traversed by light at a zone joint are substantially equal in zones adjacent the zone joint. A method for wavelength to detector array pixel location calibration of spectrometers is also disclosed, capable of accurately representing the highly localized nonlinearities of the calibration curve in the vicinity of zone joints of an order sorting filter.

Abstract: A method of making a plurality of micro-optical systems includes providing a plurality of diffractive optical elements and aligning each diffractive optical element with a refractive optical element. Each micro-optical system includes a refractive optical element and a diffractive optical element. The diffractive optical element provides different focal lengths at three different wavelengths for each micro-optical system and includes adjacent steps within a cycle having a difference of more the 2? for at least one of the three different wavelengths.

Abstract: Provided is a photonics device. The photonics device includes a distribution Bragg reflector (DBR), first and second waveguides disposed at both sides of the DBR, first lenses disposed between the DBR and the first waveguides, and second lenses disposed between the DBR and the second waveguides.

Abstract: A double-layer grating structure for efficient retroreflection of incident radiation and efficient transmission of the undiffracted incident radiation is disclosed. The grating is constructed of two spaced-apart layers of periodically arranged metal stripes, wherein the stripes in one layer overlap with gaps between the stripes in the second layer. The layers are encapsulated with a dielectric material. A method for producing such grating is also described.

Abstract: A method and apparatus for a projection display system includes a spatial light modulator and a volume illumination hologram. The spatial light modulator comprises a digital micromirror device, and the projection system includes a laser light source to produce a sequence of collimated, colored, light beams for the illumination hologram. Waste light produced by the spatial light modulator is transmitted to the illumination hologram, and the illumination hologram emits waste light from at least one of its edges. Waste light emitted from an edge of the illumination hologram is absorbed by a light sensor to control the intensity of the light beams. A projection focusing element is mounted proximate a side of the illumination hologram to focus the image beam from the spatial light modulator for viewing. A projection hologram is interposed between the side of the illumination hologram and the projection focusing element to manage waste light.

Abstract: In an aspect, described herein is a dynamically controllable optoelectronic smart window which utilizes a diffraction grating for selective transmission or rejection of a specific region of the electromagnetic spectrum, for example the infrared, near-infrared and/or visible regions. Window embodiments described herein may further utilize a selectively controlled and/or patterned total internal reflection layer to assist with the selective rejection of a specific spectral region while allowing for transmission of another specific spectral region. In another aspect, the present invention provides methods for dynamically controlling the transmission or rejection of solar near-infrared and/or visible radiation.

Abstract: A detector includes a light detecting layer and a grating structure. The light detecting layer, which can be a photodiode, has an optical mode that resonates in the light detecting layer, and the grating structure is positioned to interact with the optical mode. The grating structure further couples incident light having a resonant frequency into the optical mode, and causes destructive interference to prevent light having the resonant frequency from escaping the detecting layer. The light detecting layer can be made transparent to light having other frequencies, so that a stack of such detectors, each having a different resonant frequency, can be integrated into a WDM detector that is compact and efficient.

Abstract: The present invention relates to pigments comprising or consisting of a layer made of a material with an index of refraction that is higher than the index of refraction of the adjacent material by at least 0.25; whereas said layer has a zero-order diffractive micro-structure; whereas said layer acts as an optical waveguide and whereas said layer has a thickness between 50 nm and 500 nm; to processes for its manufacture and to its use. These pigments show a colour effect upon rotation and/or tilting, and it is believed that this colour effect is based on zero-order diffraction.

Abstract: In the diffraction grating low-pass filter, the diffraction grating has a refractive index variation region having a refractive index different from that of the glass substrate and having a lattice shape in the glass substrate, and the refractive index variation region includes a plurality of phases depending on differences of optical path lengths. Furthermore, in the diffraction grating low-pass filter, a region having an array of two rows and two columns in which regions of phases 0 and 2? are arranged in one diagonal direction and regions of phases ? and 3? are arranged in the other diagonal direction is set as a unit grating.

Abstract: A spill light removing device includes a first blocker which is located perpendicularly to a stream route of light being irradiated from a light source and blocks a stream of light that is incident to the surface of the first blocker, except on a hole formed on the first blocker; a pass-through tunnel which is connected to the hole and is formed in the same direction to the stream route of light and allows the stream of the light to pass through; and a second blocker which has a irregularity pattern that is formed on a inner wall of the pass-through tunnel and reflects the light that is incident in the deviated direction of the stream route of light.

Abstract: An optical apparatus for transmitting light having a spectrum of wavelengths is disclosed. The apparatus comprises a plurality of optical devices design and constructed to decompose the light into a plurality of portions, respectively corresponding to different sub-spectra of the spectrum, such that each portion of the light is transmitted within a different optical device.

Abstract: A compact zoom lens includes a first lens unit disposed closest to an object side, an aperture, and a rear lens group. The first lens unit includes a first diffraction optical part having positive refractive power, and the rear lens group includes a second diffraction optical part having positive refractive power. The power relation between the two diffraction optical parts and the positions of the diffraction optical parts are set appropriately. The zoom lens can have a high zoom ratio wherein chromatic aberration is fully corrected, and an image pickup apparatus employing this zoom lens can be provided.

Abstract: An optical element includes: a substrate having a plurality of first regions and a plurality of second regions that are partitioned in plan view; a first grid one-dimensionally formed in the plurality of first regions on the substrate; a diffraction function portion including a plurality of grooves parallel to each other in the plurality of second regions on the substrate; and a second grid formed in a region excluding the plurality of grooves on the diffraction function portion. The optical element reflects a part of incident light and transmits a part of the incident light.

Abstract: A light is incident on a refractive diffraction grating 13, and is distributed for each of wavelengths at different angles to be outputted. A lens 14 converts the distributed lights into belt-shaped lights, and the belt-shaped lights are incident on a mirror substrate 15 having selective reflection regions 17-1 to 17-x. By moving the mirror substrate 15 toward a direction different from a distribution direction of the belt-shaped lights, only the light of any one of wavelengths is reflected. Then, the light returning to the refractive diffraction grating 13 is reflected to an incident direction of the original light. Accordingly, a tunable filter which is able to select a light of an arbitrary wavelength by moving the mirror substrate 15 can be realized.

Abstract: The present invention provides a wavelength-selective diffraction element, configured such that light having a plurality of wavelengths are incident thereon as incident light, which is provided with: a transparent substrate; a concavo-convex part, formed on the transparent substrate such that concave portions and convex portions are cyclically extended in one direction, and comprised of a first material which is optically isotropic; and a filling part, filling at least the concave portions and comprised of a second material which is optically isotropic. The first material and the second material have no absorbance with respect to the wavelengths of the incident light. The first material and the second material have an identical refractive index with respect to light having a first wavelength which is at least one of the wavelengths of the incident light.

Abstract: The present invention relates to an isotropic zero-order diffractive colour filter, to a method to manufacture an embossing tool and to a method to manufacture such a filter. The zero-order diffractive colour filter comprises diffractive microstructures and a wave-guiding layer, wherein the diffractive microstructures possess a short range ordering over at least four times the period of the microstructures, and the diffractive microstructures possess a long range disordering over length scales of more than 100 ?m.

Abstract: Disclosed herein is a display device using a single-panel diffractive light modulator. The display device includes a light source unit, a condensing unit, an illumination unit, a diffractive light modulator, a projection unit, a filter unit, and a distortion correcting means.

Abstract: A zero order diffractive filter for polarised or unpolarised polychromatic light, comprises a grating line (10) microstructure (1) formed by a surrounding medium (12) with low index of refraction nlow and a waveguiding layer (11) with high index of refraction nhigh, the grating lines (10) having a period length ? that is smaller than the wavelength of light for which the filter is designed. A plurality of single nanostructures (2) with dimensions in the nanometre range is superposed on a first interface (13) between the surrounding medium (12) and the waveguiding layer (11).

Abstract: A beam steering system having first diffraction gratings, each one being associated with a corresponding one of a first plurality of grating vectors disposed substantially in a first plane. The gratings diffract optical energy from any one of a plurality of input directions of resonance to a corresponding one of a plurality of output directions. Second diffraction gratings are associated with a second plurality of grating vectors disposed substantially in a second plane. Each one of the second gratings diffracts optical energy from any one of a plurality of input directions of resonance to a corresponding one of a plurality of output directions.

Abstract: A microscope apparatus is based on structured illumination that can obtain an excellent super-resolved image by using even an optical system in which distortion aberration remains. Therefore, the microscope apparatus includes an illuminating optical system for illuminating a sample with light from a light source, a modulating unit that is disposed in the illuminating optical system and spatially modulates the light from the light source, an image-forming optical system for forming an image of a modulated image from the sample illuminated with the spatially modulated light, an imaging unit for picking up the demodulated image, a correcting unit for correcting distortion of the modulated image due to at least one of the illuminating optical system and the image-forming optical system, and an image generating unit for generating an image of the sample from the modulated image corrected by the correcting unit.

Abstract: A diffractive optical filter comprises a bulk material (1) having a first refractive index, a volume diffraction grating structure (2,3) having a second, different, refractive index embedded in the bulk material (1), and a mirror (4) formed within or on the surface of the bulk material (1) behind the grating structure (2,3). By placing the mirror (4) immediately behind the grating structure (2,3) the diffractive structure is effectively doubled and consequently the number of effective optically active layer is doubled. Such diffractive optical filters may be used as diffractive identification devices bonded to articles whose authenticity needs to be established.

Abstract: The present invention relates to conjugated polymers and a method for their synthesis. Furthermore, the present invention relates to electro-synthesis methods for producing polymers that include the use of at least one Lewis acid and at least one proton trap to form organic conjugated polymers having elevated refractive indices. In one embodiment, the present invention relates to an organic polymer having an elevated refractive index, the organic polymer formed by a process comprising the steps of: providing a solution of unsaturated organic monomer units and at least one acidic component; impeding saturation of the unsaturated organic-monomer units by at least one protic element in the solution; and polymerizing the unsaturated organic monomer units to form a conjugated organic polymer having a refractive index of at least about 2.3 for electromagnetic energy having a wavelength of about 700 nm.

Abstract: The invention concerns a surgical microscope (2, 3, 5) having a novel laser illumination system (11) and, in a preferred embodiment, an arrangement in which a diffractive element (7) produces an additional illuminating beam and a measurement beam.

Abstract: The invention concerns an optical security element having a substrate layer, in which a first microstructure for producing a first optically perceptible effect is shaped region-wise in a surface region. The surface region is divided into microscopically fine pattern regions and a background region. The first microstructure is shaped in the pattern regions but not in the background region. The microscopically fine pattern regions in the surface region are arranged in the form of a moire pattern into which a concealed item of information which can be evaluated by means of an associated verification element is encoded as a security feature. The microscopically fine pattern regions are further substructured in accordance with a substructuring function which describes a microscopic substructuring, serving as a further security feature, of the moire pattern.

Abstract: A beam steering system having first diffraction gratings, each one being associated with a corresponding one of a first plurality of grating vectors disposed substantially in a first plane. The gratings diffract optical energy from any one of a plurality of input directions of resonance to a corresponding one of a plurality of output directions. Second diffraction gratings are associated with a second plurality of grating vectors disposed substantially in a second plane. Each one of the second gratings diffracts optical energy from any one of a plurality of input directions of resonance to a corresponding one of a plurality of output directions.

Abstract: An exit pupil extender wherein the relative amount of different color components in the exit beam is more consistent with that of the input beam. In order to compensate for the uneven amount in the diffracted color components in the exit beam, the exit pupil extender, comprises a plurality of layers having additional diffraction gratings so as to increase the amount of diffracted light for those color components with a lower amount. Additionally, color filters disposed between layers to reduce the diffracted light components with a higher amount.

Abstract: Affords efficiently and at low cost optical fibers capped at the end with a working, tiny optically diffractive film. An optical fiber includes a diffractive film formed onto an endface thereof, or onto the endface of a collimator joined to the endface of the fiber; the diffractive film includes a transparent DLC (diamond-like carbon) layer; and the DLC layer includes a modulated-refractive-index diffraction grating containing local regions of relatively high refractive index and local regions of relatively low refractive index.

Abstract: A diffracting optical filter for use with telescopes provides a plurality of cells separated by opaque lines on an translucent substrate, the spacing of the cells proportionally spaced to match the Airy disk of a specific optical system for the telescope to aid observation through a turbulent atmosphere.

Abstract: All-dielectric diffractive pigment flakes can be applied to an object to impart a diffractive effect to the object without substantially changing the background color of the object. In one case, such diffractive pigment flakes can be applied to a white object to impart a white diffractive effect. The thickness of the dielectric layers in the diffractive pigment flakes can be chosen to provide thin-film interference, as well as diffraction from the interfaces between layers patterned with a diffraction grating. In some cases, the thin-film interference can provide color shifting in addition to the diffractive effect.

Abstract: A grating that includes a multilayer structure that has alternating layers of materials, a plurality of grooves formed between a plurality of lands, wherein at least one structural parameter of the plurality of grooves and plurality of lands is formed randomly in the multilayer structure.

Abstract: Output power fluctuations in a distributed feedback laser arrangement are reduced by inducing a saturable absorption grating in a saturable absorption region. Light is coupled into a DFB region and amplified in an amplification region. A feedback loop reflects a portion of the amplified light, and the counter-propagating beams induce an absorption grating in a saturable absorption region which suppresses output oscillations. The amplification region can comprise an erbium doped fiber, and the saturable absorption region can comprise an underpumped portion of such a fiber, or a further length of such fiber, or a planar waveguide.

Abstract: A display system includes a diffraction grating that generates exit-pupil images, where one of the exit-pupil images has a first intensity and the remaining exit-pupil images each have or approximately have a second intensity that is less than the first intensity. The system also includes a filter that attenuates the intensity of the one exit-pupil image. In one example, the filter attenuates the 0th-order exit-pupil image so that all of the exit-pupil images have the same or approximately the same intensities.

Abstract: An aberration correction device for correcting aberration produced in a light beam, which includes: a first electrode layer and a second electrode layer being opposed to each other; and a liquid crystal disposed between the first electrode layer and the second electrode layer for producing a change in phase in a light beam passing therethrough in accordance with voltages applied to the first electrode layer and the second electrode layer. The first electrode layer is divided into a plurality of phase adjustment portions which are electrically isolated each other. Each of the plurality of phase adjustment portions includes a pair of electrodes arranged in such a form that produces an electric field distribution for correcting the aberration by applying predetermined voltages thereto.

Abstract: A reflective liquid crystal display (1) is provided with a front illumination unit. The front illumination unit comprises a flat waveguide (2), at least one surface of which is provided with a diffraction grating (7). A period of the diffraction grating (7) is of the order of the wavelength of the light. A light source (4) generates light of one or more colors, and the colors of light are sequentially coupled into the flat waveguide (2). The diffraction grating (7) is divided into separate areas (10, 11, 12). Each of these separate areas (10, 11, 12) is tuned to one particular wavelength of the light generated by the light source (4). Each separate area (10, 11, 12) is subdivided into various small areas so that the surface of the flat waveguide is subdivided into a large number of small areas (10-1, 11-1, 12-1, . . . 10-11, . . . 12-41). Each small area (10-1, 11-1, 12-1, . . . 10-11, . . . 12-41) is bounded by small areas (10-1, 11-1, 12-1, . . . 10-11, . . . 12-41) tuned to other light wavelengths.

Abstract: A system to project the image of a virtual input device includes a substrate bearing a diffractive pattern, and a source of collimated light, such as a laser diode. The collimated light interacts with the substrate and the pattern to project a user-viewable image that preferably is the image of a virtual input device. Interaction between a user and the projected image of the virtual input device can then be sensed, and used to input information or otherwise control a companion device, for example a PDA or a cellular telephone.

Abstract: Disclosed is an illumination system using optical feedback to maintain a predetermined illumination output. The illumination system employs an electrically controllable optical filter for filtering light incident thereon. The illumination system also includes a light detector for detecting at least a portion of the light filtered by the electrically controllable optical filter. The light detector is in data communication with the electrically controllable optical filter. Some or all light filtered by the electrically controllable optical filter is detected by the light detector, which, in turn generates a corresponding signal that is compared to at least one predetermined value. If the signal generated by the light detector differs when compared to the at least one predetermined value, one or more filtering characteristics of electrically controllable optical filter are varied which, in turn, varies the amount of light filtered by the electrically controllable optical filter.

Abstract: A method and apparatus for control of optical trap arrays and formation of particle arrays using light that is in the visible portion of the spectrum. The method and apparatus provides a laser and a time variable diffractive optical element to allow dynamic control of optical trap arrays and consequent control of particle arrays and also the ability to manipulate singular objects using a plurality of optical traps. By avoiding wavelengths associated with strong absorption in the underlying material, creating optical traps with a continuous-wave laser, optimizing the efficiency of individual traps, and trapping extended samples at multiple points, the rate of deleterious nonlinear optical processes can be minimized.

Abstract: The use of one or more wavefront modulators in the observation beam path and/or illumination beam path of a microscope provide various advantageous results. Such modulators may be adapted to change the phase and/or the amplitude of light in such a way to carry out displacement and shaping of the focus in the object space and correction of possible aberrations. The possible areas of use include confocal microscopy, laser-assisted microscopy, conventional light microscopy and analytic microscopy.

Abstract: A condenser system for generating a beam of radiation includes a source of radiation light that generates a continuous spectrum of radiation light; a condenser comprising one or more first optical elements for collecting radiation from the source of radiation light and for generating a beam of radiation; and a diffractive spectral filter for separating first radiation light having a particular wavelength from the continuous spectrum of radiation light. Cooling devices can be employed to remove heat generated. The condenser system can be used with a ringfield camera in projection lithography.

Abstract: The present invention is a method and apparatus for a rotating, tunable, holographic drop filter connected to a fiber optic source. The filter uses a quasi phase-conjugate optical system for a drop-channel fiber coupling and WDM channels which are introduced to the system. The light from these channels is collimated and passed through a volume phase holographic material so that only one WDM channel is diffracted and the rest pass through the holographic material unaffected. A quasi phase-conjugate diffracted beam is generated by the optical system to reflect the diffracted channel back towards the holographic material. The reflected light is Bragg matched to the holographic material so that it is re-diffracted along a path identical to the original incident light beam. A free-space circulator may be used to direct the diffracted beam to a fiber optic collimator, which is different from the fiber optic collimator of the incident light beam.

Abstract: In a FLIR/laser based targeting and imaging system, the ability to recognize, detect, locate, and/or track targets in an area of interest is significantly improved by reducing the fixed and dynamic alignment errors between the IR LOS and the laser LOS. Fixed alignment errors are reduced with an improved internal boresight module and corresponding boresight method. Dynamic alignment errors are reduced with an opto-electric subsystem that employs a single pitch bearing and a common pitch/yaw afocal for both the laser energy and the IR energy. A segmented window in the system housing includes a circular EMI grid pattern which significantly reduces the amount of off-axis EMI entering the optical pathways, and improved signal processing techniques are employed to enhance the quality of the IR image after the image has been digitized.

Abstract: Disclosed is a projection optical system with a diffractive optical element, wherein the diffractive optical element is arranged so that a portion of or most of diffraction light not to be used for projection of an image is prevented from being incident inside an image projection range upon an image plane.

Abstract: A fabric is constructed to act as a diffraction grating for deBroglie waves of the continuous electromagnetic spectrum. The fabric is made by coating or laminating emissive layers on each side of a fabric and then etching one side to create a diffraction grating. The thickness of the fabric and the width of the etch determine diffracted wave lengths. Constructive or destructive interference can be established to increase the energy (constructive) or decrease the energy (destructive) of the waves diffracted proportionate to the amplitude squared.

Abstract: Disclosed is a method of characterizing a coded object having a plurality of regions. A luminosity value of a first region of the coded object is compared to a luminosity value of a second region of the coded object, wherein the second region's color is known. The first region's color is then determined based on the comparison of the first and second region's luminosity values. In one aspect, the second region's color is known to be white. It is determined that the first region's color is white when the first region's luminosity value is not less than the second region's luminosity value by more than a predetermined constant k, and it is determined that the first region's color is black when the first region's luminosity value is less than the second region's luminosity value by more than a predetermined value. Various coded object configurations are also disclosed.

Abstract: An energy saving window system operates selectively in different seasons and climatic conditions to optimize transfer of the sun's radiation through the window into an interior space. Two sets of diffraction gratings are deployed, with two mode settings--a summer or capture mode and a winter or transmittance mode. In the summer mode, transfer of heat into the interior is undesirable. Unwanted heat rays are redirected to a scupper by additive diffraction through two diffraction gratings in series. The scupper redirects the undesired radiation to a heat sink or back out through the window. In the winter mode, transfer of heat into the interior is desirable. By repositioning the two diffraction gratings so that their deflections are subtractive, the sun's rays are redirected to be essentially undiffracted so as to miss the scupper and enter the room. The essentially undiffracted light rays are acceptable as a view and are effectively unblocked as to solar heat gain.

Abstract: An advanced design for a phase plate enables the distribution of spots in arbitrarily shaped patterns with very high uniformity and with a continuously or near-continuously varying phase pattern. A continuous phase pattern eliminates large phase jumps typically expected in a grating that provides arbitrary shapes. Large phase jumps increase scattered light outside of the desired pattern, reduce efficiency and can make the grating difficult to manufacture. When manufacturing capabilities preclude producing a fully continuous grating, the present design can be easily adapted to minimize manufacturing errors and maintain high efficiencies. This continuous grating is significantly more efficient than previously described Dammann gratings, offers much more flexibility in generating spot patterns and is easier to manufacture and replicate than a multi-level phase grating.