Abstract: The invention concerns a grating structure by high dispersion volume holography and applies, for example, to pulse compression or stretching devices.

Abstract: A fiber-optic modulator based on a micromachined grating device which is both polarization independent and achromatic in behavior is described. The device is a two dimensional grating or periodic structure which is symmetric in the X and Y axes. It is comprised of a membrane with holes cut in it that moves downward with the application of a voltage which starts diffracting light. The hole region may have a raised island to provide achromatic behavior.

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: A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.

Abstract: A tunable filter includes a polarizer, a polarization rotator, a diffraction grating and a diffraction grating adjustor. The polarizer polarizes a light beam and splits the light beam into first and second light beams. The polarization rotator rotates a plane of polarization of the first light beam at 90° to generate a rotated light beam. The diffraction grating receives the rotated light beam and the second light beam. The diffraction grating adjustor adjusts the diffraction grating to change incident angles of the rotated light beam and second light beam.

Abstract: A diffraction grating that achieves high diffraction efficiency at all polarizations for optical signals at telecommunications wavelengths is provided. The diffraction grating has a substrate and a plurality of reflective faces oriented at respective blaze angles &thgr;b spaced along the substrate surface, with the blaze angles substantially differ from the Littrow condition. Each reflective surface is supported by a support wall connected substantially with the substrate surface.

Abstract: In one aspect of the invention, an apparatus operable to provide optical signal processing includes an inner conductive layer including an at least substantially conductive material and a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns. At least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a diffraction of the input optical signal wherein a majority of the diffracted input signal is communicated in one direction.

Abstract: A renewable liquid reflection grating. Electrodes are operatively connected to a conducting liquid in an arrangement that produces a reflection grating and driven by a current with a resonance frequency. In another embodiment, the electrodes create the grating by a resonant electrostatic force acting on a dielectric liquid.

Abstract: An optical beam steerer includes one or more layers of electro-optically active material in which is formed a chirped distributed Bragg reflector. An electric field generated across the electro-optically active material in the direction of propagation of the chirped distributed Bragg reflector causes the index of refraction within the material to change. The electric field varies in a direction normal to the direction of propagation of the chirped distributed Bragg reflector which causes a variation in the local index of refraction proportional to the strength of the electric field. Changes in the index of refraction cause the wavefront of the incident optical beam to experience different delays such that the incident optical beam is reflected out of the beam steerer at an angle that is tangential to the direction of variation of the applied electric field. Two dimensional beam steering is provided by the creation of two electric fields that are orthogonal to each other.

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: A micro-opto-electro-mechanical systems (MOEMS) modulator based on the phenomenon of frustrated total internal reflection (FTIR). The modulator effects amplitude and phase modulation at the boundary of a waveguide. Wavelength-specific switching is achieved by spatially separating the wavelength channels by dispersing a broadband input signal into its wavelength components through a grating. In exemplary embodiments, an array of micro-fabricated actuators is used to switch or modulate wavelengths individually. Applications include wavelength and space-resolved phase and amplitude modulation of optical beams, and re-configurable add/drop switching of dense wavelength-division multiplexed (DWDM) optical communication signals.

Abstract: A renewable liquid reflecting zone plate. Electrodes are operatively connected to a dielectric liquid in a circular or other arrangement to produce a reflecting zone plate. A system for renewing the liquid uses a penetrable substrate.

Abstract: The present invention provides an improvement in a wavelength division multiplexer and/or a dense wavelength division multiplexer (WDM/DWDM) by incorporating an electronically reconfigurable diffraction grating. The introduction of the electronically reconfigurable diffraction grating, which is typically fabricated using MEMS (microelectromechanical systems) technology, improves the compact design, durability, and dynamic functionality of the WDM/DWDM system.

Abstract: Disclosed is a laser diode unit for an optical pick-up apparatus capable of applying a laser beam emitted from a laser diode to an optical disc and a monitor photodiode (PD) using an integral optical system. The laser diode unit includes a laser diode for emitting a laser beam, a monitor PD for controlling recording optical power, an optical disc on which data is written by the laser beam or from which data is read by the laser beam, and a lens module for reflecting a part of the light beam emitted, in the form of a divergent light beam, from the laser diode, thereby focusing the light beam onto the optical disc, the lens module also serving to transmit the remaining part of the light beam therethrough, thereby allowing the transmitted light beam to be converged by the monitor photodiode.

Abstract: A display system, that includes a light source for 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 lens system for projecting light onto a screen; an obstructing element for blocking a discrete number of diffracted light beams from reaching the screen; a scanning element for moving non-obstructed diffracted light beams on the screen; and a controller for providing a data stream to the individually operable devices.

Abstract: A polarization conversion optical system converts light having a nonuniform plane of polarization into light having a uniform plane of polarization. The system includes a multilayer dielectric film at the side upon which the target light is incident. The film exhibits the property that it reflects one polarized component of the light and transmits a second polarized component of the light at a first angle of incidence, but transmits the first component at a second angle of incidence. Incident target light that is transmitted through the film at the first angle of incidence passes through a quarter-wavelength plate and is reflected at the second angle, whereupon it is retransmitted through the quarter-wavelength plate to be converted from one plane of polarization to the other. It is then emitted from the dielectric film in the same plane of polarization as light reflected by the film.

Abstract: A diffraction grating for use in multiplexing and demultiplexing optical signals in optical communication systems having reduced polarization sensitivity has a plurality of grooves including reflective step surfaces and transverse riser surfaces separated by a flat. The step surfaces have a reflective coating and the riser surfaces do not have a reflective coating. A method of making a reflective diffraction grating includes forming a plurality of grooves in a substrate, the grooves having a step surface for reflecting an incident beam, a transverse riser and a flat therebetween and providing a reflective coating on the steps and not on the risers.

Abstract: The present invention relates to the tailoring the reflectivity spectrum of a SGDBR by applying digital sampling theory to choose the way each reflector is sampled. The resulting mirror covers a larger wavelength span and has peaks with a larger, more uniform, coupling constant (&kgr;) than the mirrors produced using conventional approaches. The improved mirror also retains the benefits of the sample grating approach. Additionally, most of the embodiments ate relatively simple to manufacture.

Abstract: Techniques for fabricating a well-controlled, quantized-level, engineered surface that serves as substrates for EUV reflection multilayer overcomes problems associated with the fabrication of reflective EUV diffraction elements. The technique when employed to fabricate an EUV diffraction element that includes the steps of: (a) forming an etch stack comprising alternating layers of first and second materials on a substrate surface where the two material can provide relative etch selectivity; (b) creating a relief profile in the etch stack wherein the relief profile has a defined contour; and (c) depositing a multilayer reflection film over the relief profile wherein the film has an outer contour that substantially matches that of the relief profile. For a typical EUV multilayer, if the features on the substrate are larger than 50 nm, the multilayer will be conformal to the substrate. Thus, the phase imparted to the reflected wavefront will closely match that geometrically set by the surface height profile.

Abstract: A dot matrix hologram with a hidden image is disclosed, wherein the hidden image technology is applied to a dot matrix hologram. Although the hidden image technology has been used in a conventional hologram, it has not been used in a dot matrix hologram. Although the above two kinds of hologram both can show hidden images with illuminating laser light, the disclosed dot matrix hologram with a hidden image and the conventional hologram with a hidden image use different working principles and have different detailed characteristics to create hidden image regions.

Abstract: Disclosed is a diffractive optical element which includes a diffractive grating pattern on a base plate. The diffractive grating pattern includes a plurality of phase gratings arranged in parallel lines extending along a predetermined direction to cause diffraction of an incident beam. Each of the plurality of phase gratings has an asymmetrical phase pattern. There is a phase gap, &Dgr;P, representing a phase difference (in radians) between an end point and a beginning point of each phase pattern. The phase gap, &Dgr;P, is substantially equal for each of the plurality of phase gratings and satisfies the relationship. 0.7&pgr;<|&Dgr;P|<1.2&pgr;.

Abstract: A system for modulating a beam of light in accordance with an input data stream having a data rate greater than 2 MHz, includes a source of light for directing light along a predetermined path, and a self-damped electromechanical conformal grating disposed in the predetermined path, the self-damped electromechanical conformal grating. The self-damped electromechanical conformal grating includes an elongated ribbon element including a light reflective surface, a substrate and a pair of end supports for supporting the elongated ribbon element at both ends over the substrate; and at least one intermediate support between the end supports so that there are deformable portions of the elongated ribbon element above and movable into a channel containing a gas.

Abstract: The invention relates to the field of optical fiber wavelength division multiplexed transmission, and more particularly to the field of narrow-band optical filters for dense multiplexing. The invention proposes a narrow-band optical filter with a group-delay response that is very flat in the working band, obtained by cascading two Bragg gratings having group delays that are linear as a function of wavelength in the working band, but with their gradients being of opposite signs. The present solution is easier and less costly to implement than the prior art solutions, and it should also offer higher performance.

Abstract: A system for modulating a beam of light in accordance with an input data stream having a data rate greater than 2 MHz, includes a source of light for directing light along a predetermined path; a self-damped diffractive light modulator disposed in the predetermined path and having a plurality of spaced apart self-damped deformable elements being disposed relative to each other and secured at opposite ends and suspended above and movable into a channel containing a gas, and each spaced apart self-damped deformable element having at least one reflective surface. The spaced apart self-damped deformable elements respond to an input data stream and are sufficiently damped to minimize the introduction of data errors into the modulator light beam.

Abstract: A reflection type diffraction grating according to the present invention has a structure in which a metal film as a first layer with reflectance not lower than 30% with respect to the wavelength of incident light and a transparent dielectric film as a second layer are laminated successively on the surface of the reflection type diffraction grating. With respect to the wavelength of incident light, the metal film has a refractive index selected to be not higher than 1.5 and an extinction coefficient selected to be not smaller than 6.0. The transparent dielectric film has a refractive index selected to be in a range of from 1.30 to 1.46, both inclusively, with respect to the wavelength of incident light and has an optical film thickness selected to be in a range of from 0.20&lgr; to 0.38&lgr;, both inclusively, when &lgr;is the wavelength of incident light.

Abstract: A surface pattern (1) has N visually recognizable patterns which are composed of optically diffractive, microscopically fine relief structures, plane mirror faces or absorbing or scattering structures. The N patterns share at least one independent common surface element (11). The surface element (11) is subdivided into surface parts and has an arrangement of the surface parts which is independent of the N patterns, which has a predetermined structure, and which is not recognizable to the naked eye. A single microscopically fine diffraction structure or a structure which has an absorbing or scattering property or is a plane mirror is applied to each surface part. The relief structures, diffraction structures and other structures are embedded in a plastic laminate (20) and can have their optical performance enhanced by a reflection layer (21). The surface pattern (1) is applied as a security element to a document (2) and allows the document (2) to be identified by machine in a reading machine.

Abstract: A diffraction grating (1) has a multiplicity of parallel diffraction structures succeeding one another periodically. The latter are arranged on a support (2) and each incorporate a slat (3) extending from a base area (4) of the support (2). Said slat has a substantially rectangular cross-section. The width w of the slat (3) comes to less than 100 nm, preferably between 20 nm and 60 nm, more preferably in the area of 50 nm. Advantageous uses of the diffraction grating (1) are obtained e.g. in a Littrow configuration, preferably in third order of the incident light beams (8), in particular at a light wavelength that is less than 250 nm.

Abstract: An optical element includes an incidence surface, one or more reflecting surfaces reflecting light from the incident surface, an emergence surface, and off-axial curved surfaces causing the light to emerge from the emergence surface. At least one of the incidence surface, the emergence surface and the one or more reflecting surfaces is a surface having diffracting action. The surface having the diffracting action is a curved surface.

Abstract: A reflective-type diffraction grating structure for use in color display devices such as liquid crystal displays (LCDs). It contains: (1) a plurality of micro-lenses each having a smooth top surface and a blazed zig-zag-shaped grating surface at the bottom; (2) an optical coating formed below the zig-zag-shaped grating surface; and (3) a reflective member formed below the optical coating. With the cooperative actions of the zig-zag-shaped grating surface, the optical coating layer, and the reflective member, an incident light, when reflected, is separated into repeated sequences of red, green, and blue color components and a black matrix segregating the red, green, and blue color components. A sequence of micro-light valves are placed in the path of the reflected incident light to block the undesired color components. The reflective-type diffraction grating structure dispenses with the need for the various layers of color filters.

Abstract: A micro relief element which comprises a) a first layer of a first substrate, the first layer having a receptive surface capable of retaining a relief forming polymer; b) an overlay of a desired thickness of the relief forming polymer over the receptive surface; and c) at least one relief feature formed from the relief forming polymer and which protrudes above the overlay; structures and elements comprising such micro relief element; micro-optical, micro-fluidic, micro-electrical and micro-chemical applications thereof; and a method and apparatus for the preparation thereof.

Abstract: An apparatus consisting of a cable grid system for lighting in which a light can be positioned at any location on a ceiling. Optionally, the light fixtures can include a diffraction grating reflector (such as a music CD) to reflect light patterns onto the ceiling from a light source which is preferably a point source. Also, light fixtures with diffraction grating reflectors could be mounted on a wall, table, or on the ceiling without using a cable grid system.

Abstract: A reflective liquid crystal display panel has a two-dimensional array of reflective pixel electrodes. A diffraction grating is provided in the border spaces between the neighboring reflective electrodes. The diffraction grating diffracts the incident light sideways, thereby subtracting it from the total returned light, which increases the available optical contrast. The diffraction grating is tuned to the peak wavelength of the ambient illumination. It is formed as additional structure on the substrate during fabrication. The structure uses raised mesas arranged in a checker board pattern. The mesas define floors between them, and have roofs that are raised from the floors by a quarter wavelength.

Abstract: An optical device is described. In one embodiment, the optical device includes first and second concave diffraction gratings, first and second concentrators, first and second sets of fibers, and an array of optical elements. The first concave diffraction grating reflects light from an input beam into multiple light waves of different wavelengths focused at spatially separate locations. The first concentrator has a first set of light guiding channels to transfer the light waves. The first set of fibers is optically coupled to the first set of light guiding channels. The array of optical elements includes optical elements that have at least one input and at least one output. Such inputs of each optical element in the array is coupled to one of the first set of light guiding channels. The second set of fibers is optically coupled to outputs of optical elements in the array. The second concentrator has a second set of light guiding channels.

Abstract: A diffractive optical element includes a first layer having a relief type grating, a second layer having a relief type grating, and a third layer having a relief type grating. The first, second and third layers are formed of different materials. The diffractive optical element has at least three diffraction optical parts in the boundary areas of the respective layers. The diffractive optical element is set so that at least wavelengths, the diffraction efficiency thereof for diffracted light of a predetermined order may be maximum. The three wavelengths are substantially coincident with the main wavelengths of the three primary colors.

Abstract: A pixellated diffractive device includes a multiplicity of pixels (12,22) in turn divided into multiple sub-pixels (13,23). The device is related to one or more pixellated diffraction surface structures which when illuminated generate respective corresponding optically variable images. The sub-pixels (13,23) of each pixel of the diffractive device include diffractive elements (13a,23a) arranged in one or more groups, the diffractive elements of each group matching diffractive elements of a corresponding single pixel of the respective pixellated diffraction surface structures. In each pixel of the device the diffractive elements (13a,23a) of the or each said group are intermixed with other sub-pixels and cooperatively contribute a single element of the corresponding optically variable image which is generated on illumination of the diffractive device.

Abstract: The invention relates to a system comprising a series of data carriers, in particular identity cards, papers of value or the like, whereby the data carriers belonging to the system exhibit diffraction structures containing standard information and parts of the series are changed by additional measures in the area of the diffraction structures or combined with other elements and they differ from the rest of the series in optically recognizable fashion, whereby the change in the diffraction structures and/or the combination with other elements convey an esthetic overall impression and the change and/or combination with the other elements cannot be undone without destruction of the diffraction structures.

Abstract: A mechanical grating device for modulating an incident beam of light by diffraction includes an elongated element including a light reflective surface; a pair of end supports for supporting the elongated element at both ends over a substrate; at least one intermediate support between the end supports; and means for applying a force to the elongated element to cause the element to deform between first and second operating states

Abstract: A spatial light modulator pixel includes a flexible reflective surface that is electrostatically actuated to control the surface shape and thereby phase-modulate reflected light. The reflected light is filtered by a projection aperture, wherein the phase modulation controls the amount of light from the pixel that is filtered through the aperture. The spatial light modulator includes and array of such pixels, which are imaged onto a conjugate image plane, and each pixel controls the image brightness at a corresponding conjugate image point. High image contrast is achieved by using a dual-flexure pixel design in which two flexure elements operate conjunctively to maintain well-defined diffraction nodes at or near the projection aperture edges over the full modulation range.

Abstract: The object to be identified is affixed with an identification medium comprising a reflective layer consisting of a reflective hologram or diffraction grating. The high polymer cholesteric liquid crystal provides an inexpensive identification medium, and the use of the second light receiving unit for providing a reference signal provides a high S/N output signal which is highly distinct and resistant to the contamination of the identification medium. Also, the elimination of the need for expensive optical elements such as beam splitters also contributes to the reduction of cost.

Abstract: Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

Abstract: A method for damping electro-mechanical ribbon elements over a channel defining a bottom surface and having a bottom conductive layer formed below the bottom surface includes the steps of: providing at least one constant amplitude voltage pulse to at least one ribbon element wherein the actuation pulse causes the ribbon element to contact the bottom surface of the channel; and providing at least one braking pulse to the ribbon elements wherein the braking pulse is separated by a narrow temporal gap from the constant amplitude voltage pulse. Furthermore, the method can also provide a sophisticated damping for ribbon elements which are actuated so that they do not contact the bottom of the channel.

Abstract: A mechanical grating device for improving the diffraction efficiency. The mechanical grating device is built on a base having a surface. Above the base a spacer layer, having an upper surface, is provided, and a longitudinal channel is formed in said spacer layer, said channel having a first and second opposing side wall and a bottom. A plurality of spaced apart deformable ribbon elements are disposed parallel to each other. The deformable elements are organized in groups of N elements wherein N is greater than 2. When the device is actuated each of said groups forms a pattern of discrete levels wherein the pattern has n levels wherein n is greater than 2.

Abstract: An optical switch uses a micromachined adjustable phase hologram device to route optical signals from an input fiber to selected output fibers is described. The adjustable phase hologram includes a large number of micromachined reflective ribbons which can be individually controlled and adjusted to produce a wide range of phase profiles to route the light beams from the input fiber. This optical switch is capable of dealing directly with optical signals, has fast switching speeds, is capable of routing WDM input signals, is polarization independent, is scalable to large switches, and avoids the complexity of other switches.

Abstract: Stepped diffractive surfaces (13) are used to reduce variations in the optical properties of an optical system as a result of a change in the temperature of all or a portion of the system. Such surfaces have optothermal coefficients which differ from the optothermal coefficients of both kinoforms and refractive elements. Accordingly, stepped diffractive surfaces can be combined with such elements to achieve overall thermal control of optical systems employing such elements.

Abstract: An improved micro machine has at least a first element which is moveable relative to a second element such that the first and second elements can be in contact with each other. The contacting portions of both the first and second elements are protected with a long-lasting lubricant to prevent the elements from sticking or adhering to each other. The lubricant is a polar low molecular weight compound preferably applied as a vapor. This class of low molecular weight lubricants consists of acetone, ethanol, ethylene glycol, glycerol, isopropanol, methanol, and water. According to the disclosure a lubricant has a low molecular weight if its molecular weight is less than ˜100 amu, or has a vapor pressure ≧5 Torr at room temperature. The preferred micro machine is a GLV wherein the bottom of the deformable ribbon contacts the landing electrode when the reflector is in a down position (close to the substrate).

Abstract: A electro-mechanical grating device for diffracting an incident light beam has a base which defines a surface. A spacer layer is provided above the base, said spacer layer defining an upper surface of said spacer layer. A longitudinal channel is formed in said spacer layer, said channel having a first and second opposing side walls and a bottom. The side walls are substantially vertically disposed with respect to the bottom, and said channel having a constant cross section along the entire length of the mechanical grating device. A plurality of spaced apart deformable ribbon elements are disposed parallel to each other and span the channel. The deformable ribbon elements are fixed to the upper surface of the spacer layer on each side of the channel. A bottom conductive layer is provided within said base and said bottom conductive layer is limited essentially to the cross-section of the channel.

Abstract: An optical demultiplexer has light input means, a collimator lens, a substrate with a diffraction grating formed thereon, and light detecting means for detecting light demultiplexed by the diffraction grating. The diffraction grating comprises a reflective diffraction grating having a reflecting surface. The light input means and the light detecting means face the reflective diffraction grating with the collimator lens interposed therebetween. The reflecting surface includes a light transmitting area in at least a portion thereof. An optical demultiplexer having an input optical fiber, a collimator lens, a diffraction grating having a reflecting surface which includes a partial light transmitting area, and light detecting means for detecting light demultiplexed by the diffraction grating is assembled by monitoring light having passed through the light transmitting area and adjusting the position of the optical axis of the diffraction grating.

Abstract: An electro-mechanical grating device for diffracting an incident light beam has a base which defines a surface. A spacer layer is provided above the base, said spacer layer defining an upper surface of said spacer layer. A longitudinal channel is formed in said spacer layer. A plurality of spaced apart deformable ribbon elements are disposed parallel to each other and span the channel. The deformable ribbon elements define a ribbon structure which comprises at least one layer of a single material. The ribbon elements and the electro-mechanical grating device are formed so that charge build-up in layers of the electro-mechanical grating device can be avoided during operation of the device.

Abstract: A method for transferring an image to a medium includes: generating a substantially uniform line of radiation; producing diffractive light from the uniform line of radiation; passing zero order diffractive light to the medium in a telecentric fashion while blocking non-zero order diffractive light; adjusting image magnification on the medium independent of image focus in response to the zero order diffractive light; and adjusting image focus on the medium independent of image magnification in response to the zero order magnification-adjusted diffractive light.

Abstract: A photolithography system that employs a condenser that includes a series of aspheric mirrors on one side of a small, incoherent source of radiation producing a series of beams is provided. Each aspheric mirror images the quasi point source into a curved line segment. A relatively small arc of the ring image is needed by the camera; all of the beams are so manipulated that they all fall onto this same arc needed by the camera. Also, all of the beams are aimed through the camera's virtual entrance pupil. The condenser includes a correcting mirror for reshaping a beam segment which improves the overall system efficiency. The condenser efficiently fills the larger radius ringfield created by today's advanced camera designs. The system further includes (i) means for adjusting the intensity profile at the camera's entrance pupil or (ii) means for partially shielding the illumination imaging onto the mask or wafer.