Abstract: An optical pickup apparatus having laser light sources emit a first light beam having a relatively shorter wavelength for a DVD and a second light beam having a longer wavelength for a CD-R, an objective lens having a focal length of an information recording surface in the DVD, an optical path control unit controls the light beams so that the light beam emitted from one of the laser light sources is directed to the objective lens and the light output from the objective lens is directed to the optical detection unit, and a phase shift unit between the optical path control unit and the objective lens and which shifts a phase of the second light to reduce the size of a beam spot which is formed the information recording surface in the CD-R.

Abstract: The light modulator includes elongated elements and a support structure coupled to the elongated elements. Each element includes one or more lengthwise slits within an active optical area, and a light reflective planar surface with the light reflective planar surfaces lying in a grating plane. The support structure maintains a position of the elongated elements relative to each other and enables tilting of each element about a lengthwise axis. The elongated elements are tilted between a first modulator configuration wherein the elongated elements act to diffract an incident light into one or more diffraction orders, and a second modulator configuration wherein the elongated elements act to diffract the incident light into at least one diffraction order different than the one or more diffraction orders in the first modulator configuration.

Abstract: A modulator for and a method of modulating an incident beam of light including means for supporting a plurality of active elements and a plurality of bias elements, each active and bias element including a light reflective planar surface with the light reflective planar surfaces of the plurality of active elements lying in a first parallel plane and the plurality of bias elements lying in a second parallel plane wherein the plurality of active and bias elements are parallel to each other and further wherein the plurality of bias elements are mechanically or electrically deflected with respect to the plurality of active elements. Each of the plurality of bias elements is deflected an odd multiple of the wavelength of an incident light wave divided by four and the plurality of light reflective planar surfaces of the plurality of active elements move between the first parallel plane to the second parallel plane.

Abstract: Disclosed is a light modulator having a digital micro blaze diffraction grating. In the light modulator, a fine protrusion is formed on an edge of a lower surface of a diffraction member so that a reflective surface inclines due to the fine protrusion when the diffraction member is drawn downward.

Abstract: An optical MEM device is fabricated with a patterned device layer formed on a silicon wafer. Preferably, the patterned device layer is patterned with plurality of ribbons and/or access trenches. The central portion of the ribbon is released from the silicon wafer using a selective etch process, wherein a cavity is formed under the central portion of the ribbon, while opposing ribbon ends remain attached to the wafer. The selective etching process preferably utilizes an enchant comprising xenon difluoride. In accordance with further embodiments, the silicon wafer is doped, patterned or otherwise modified to enhance the selectivity of the etching process.

Abstract: An dynamic optical filter 10 is provided to selectively attenuate or filter a wavelength band(s) of light (i.e., optical channel(s)) or a group(s) of wavelength bands of an optical WDM input signal 12. The optical filter is controllable or programmable to selectively provide a desired filter function. The optical filter 10 includes a spatial light modulator 36, which comprises an array of micromirrors 52 that effectively forms a two-dimensional diffraction grating mounted in a retro-reflecting configuration. Each optical channel 14 is dispersed separately or overlappingly onto the array of micro-mirrors 52 along a spectral axis or direction 55 such that each optical channel or group of optical channels are spread over a plurality of micromirrors to effectively pixelate each of the optical channels or input signal.

Abstract: A security element for sticking onto a document comprises a layer composite of plastic material and has embedded, optically effective structures of a pattern . The optically effective structures in surface portions of the pattern are in a reference plane, defined by co-ordinate axis (x; y), of the layer composite and are shaped into a reflecting interface. The interface is embedded between a transparent shaping layer and a protective layer of the layer composite. At least one surface portion is of a dimension of greater than 0.4 mm and in the interface has at least one shaped macrostructure which is an at least portion-wise steady and differentiatable function of the co-ordinates (x; y). The macrostructure is curved at least in partial regions and is not a periodic triangular or rectangular function. In the surface portion adjacent extreme values of the macrostructure are at least 0.1 mm away from each other.

Abstract: A light reflection and diffraction element for enhancing the contrast of an image display device. In an off state of the element, a portion exhibiting a cyclic structure for diffracting incident light in a region where reflective members having reflection surfaces are aligned is reduced by preventing the generation of unrequired diffracted light. For example, by covering connection regions of the ribbon reflective members by light shielding masks, incident light is shielded. Preferably, any uneven state of the reflection surfaces of the ribbon reflective members is controlled, and a correlation length is made small.

Abstract: An apparatus providing full spectrum electronic images includes a full-spectrum light source, a programmable diffraction grating to separate light from the source into its spectral components, a reflection system controllable on a pixel by pixel basis to modulate light output from the diffraction grating, and a scanning mirror to form an image from light modulated by the reflection system. A related method for displaying a full spectrum image includes providing full spectrum light, using a diffraction grating to separate the light into its spectral components, and for each pixel of the image, modulating the intensity of the spectral components to produce a light output characteristic of such pixel, and additionally using a scanning mirror arrangement to form the image.

Abstract: An optical pickup apparatus having laser light sources emit a first light beam having a relatively shorter wavelength for a DVD and a second light beam having a longer wavelength for a CD-R, an objective lens having a focal length of an information recording surface in the DVD, an optical path control unit controls the light beams so that the light beam emitted from one of the laser light sources is directed to the objective lens and the light output from the objective lens is directed to the optical detection unit, and a phase shift unit between the optical path control unit and the objective lens and which shifts a phase of the second light to reduce the size of a beam spot which is formed the information recording surface in the CD-R.

Abstract: A volume diffractive composite is disclosed for providing illumination at a first output angle. The volume diffractive composite comprises a first plurality of grating elements that are mutually spaced from another in a first position with a first spacing period along a first plane, and an actuation unit for changing at least one of the position or the spacing period of the first plurality of grating elements to a second position or spacing period to provide illumination at a second output angle.

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: An optical device includes a plurality of metallic stripes, arranged in a substantially planar, subwavelength grating having a laterally varying, continuous grating vector, deposited on a substrate such as GaAs or ZnSe. When used as a polarizer, the device passes a laterally uniform polarized beam of electromagnetic radiation incident thereon with a predetermined, laterally varying transmissivity. When used to effect polarization state transformation, the device transforms a beam of electromagnetic radiation incident thereon into a transmitted beam having a predetermined, laterally varying polarization state. The device can be used to provide radially polarized electromagnetic radiation for accelerating subatomic particles or for cutting a workpiece. The device also can be used, in conjunction with a mechanism for measuring the lateral variation of the intensity of the transmitted beam, for measuring the polarization state of the incident beam.

Abstract: Provided is a Fresnel lens the manufacture of that is unlikely to be affected by the working errors of the die in the optical axis and its neighborhood. Two lens surfaces 11, 11 that are disposed in the vicinity of the optical axis are disposed in the way they are shifted from each other in a direction along the optical axis, whereby the height Ha in this direction of the optical axis of a non-lens surface 12 located at the boundary between the two lens surfaces 11, 11 is made greater than an original height Ha of the non-lens surface 12 in a case where it is assumed that the lower ends 11a, 11a of each of these lens surfaces 11, 11 has been placed on the same flat plane intersecting the optical axis OA at a right angle with respect thereto. Also, the lens angle ?a of at least one piece of lens surface 21 that is disposed in the vicinity of the optical axis is set to be greater than the original lens angle that should be given according to the focus calculation with respect to the lens angle 21.

Abstract: A switching element capable of being used in an optical processing device includes an optical signal separator operable to separate a multiple wavelength optical signal into one or more optical signal wavelengths. The switching element further includes a plurality of semiconductor optical amplifiers located on a single semiconductor substrate. The plurality of semiconductor optical amplifiers operable to perform an optical switching operation on at least one of the optical signal wavelengths. The switching element also includes a controller operable to generate a control signal that affects the optical switching operation performed by one or more of the plurality of semiconductor optical amplifiers.

Abstract: One embodiment disclosed relates to an apparatus for controlled diffraction of light. The apparatus includes a plurality of vertically movable reflective members and an arrangement of the reflective members along a grating plane. The grating plane is configured to be controllably tiltable. Another embodiment disclosed relates to a method for controlled diffraction of light. The method includes illuminating incident light upon an element, and controllably deflecting reflective members within the element to control a fraction of the incident light reflected by the element. The reflective members may be controllably deflected so as to be positioned along a tiltable grating plane.

Abstract: An electrostatic micromechanical device with continuously variable displacement, that includes: a movable member having a first electrode; an opposing surface having a second electrode; a channel separating the movable member from the opposing surface; a liquid situated in the channel, wherein the liquid has a sufficiently high dielectric constant so as to enable continuously variable and stable control of a displacement of the movable member over a travel range spanning at least half of the channel; the displacement being a result of a voltage applied between the first electrode and the second electrode; and at least one solid dielectric layer physically situated between the first electrode and the second electrode.

Abstract: A security element (2) comprising a plastic laminate has a surface pattern (12) composed mosaic-like from surface elements (13; 14; 15). Shaped into at least two of the surface elements (14; 15) is a respective diffraction structure {B(x, y, T)} produced from a superimposition of a low-frequency grating structure {G(x, y)} with a high-frequency relief structure {R(x, y)}. In the one surface element (14) a grating vector of the grating structure {G(x, y)} and a relief vector of the relief structure {R(x, y)} are parallel and in the other surface element (15) the grating vector (16) and the relief vector (17) include a substantially right angle. In addition the grating vectors (16) of the grating structures {G(x, y)} in the two surface elements (14; 15) are parallel. A common boundary (18) of the two surface elements (14; 15) is visible only upon lighting with linearly polarized light, in daylight both surface elements (14; 15) have the same surface brightness.

Abstract: The invention refers to electrically reconfigurable optical devices based on the use of a layer of dielectric and transparent viscoelastic material (G) opposing at least a first electrode structure (ES1). According to the invention the arrangement of the individual electrode zones in the first electrode structure (ES1) in order to deform the viscoelastic layer (G) complies with one of the following alternatives. According to the first alternative, the electrode zones of the first electrode structure (ES1) are grouped into groups composed of two or more adjacent electrode zones and within each of said groups individual electrode zones are supplied each with a substantially different voltage. According to the second alternative, the electrode zones of the first electrode structure (ES1) are substantially annular, elliptical, rectangular or polygonal closed-loop electrodes. The invention allows, for example, for creating electrically reconfigurable blazed gratings (30) or Fresnel zone lenses (40).

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 diffraction grating device operable as a reflection or transmission grating, and a method of manufacturing and using any number of such grating devices so that each device is individually electrically addressable to diffract radiation of different wavelengths. The grating device comprises first and second sets of interdigitated elements so that each element of the first set defines an element pair with an immediately adjacent element of the second set, a first gap is defined between the elements of each element pair, and a second gap is defined between each adjacent pair of element pairs. The elements of an element pair are selectively movable toward and away from each other. As such, the widths of the gaps can be selectively sized to diffract radiation of a desired wavelength.

Abstract: A diffractive focusing device includes a light transmissive substrate and a plurality of selectively light opaque elements formed in the light transmissive substrate. The selectively light opaque elements are capable of being electronically activated. Particular elements of the plurality of selectively light opaque elements are selectively rendered substantially light opaque or substantially light-transmissive in order to create light transmissive channels in the light transmissive substrate with desired diffractive characteristics.

Abstract: The present invention relates to a precision phase mask for forming diffraction grating in optical fiber and optical waveguide, to provide them with nonlinear chirped grating for dispersion compensation use and having low fluctuation or crosstalk in the group delay characteristics. The diffraction grating is formed by means of interference fringe between diffracted lights of different orders, in which the cycle of the diffraction grating 20 increases nonlinearly, wherein plurality of diffraction gratings G1, G2, G3 . . . having different cycles are assembled on a plane in increasing order of the cycle with the directions of the diffraction gratings directed to the same direction, and assembled in such a manner that, where the cycle of grating changes nonlinearly and discontinuously, the regions having larger rate of change of the cycle contain proportionally more discontinuous phases per unit length.

Abstract: A tunable optical device for adding or dropping one or more channels in a wavelength division multiplexing communication system is disclosed. The tunable optical device comprises one or more filters, wherein at least one filter comprises (a) one or more elastimers and (b) one or more gratings. An elastimer is a polymer that expands and contracts with a change in a voltage applied across the polymer or when a certain wavelength of light is diffracted from or transmitted through the polymer.

Abstract: A plane diffraction grating based on surface normal rotation according to the present invention is designed so that the profile of the grooves at a radial area is determined depending on a rotational position of the area about a rotational center defined as a foot of the rotational axis on the surface of the plane diffraction grating. An optical system such as a spectrometer or a monochromator according to the present invention uses such a plane diffraction grating, and requires a special arrangement. The optical system includes: a plane diffraction grating as described above; a mechanism for rotating the plane diffraction grating about the rotational axis; an incidence optical system for casting a converging beam of light on a point of the surface of the plane diffraction grating, where the point is set apart from the rotational center.

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 light modulator includes elongated elements arranged parallel to each other. In a first diffraction mode, the light modulator operates to diffract an incident light into at least two diffraction orders. In a second diffraction mode, the light modulator operates to diffract the incident light into a single diffraction order. Each of the elongated elements comprises a blaze profile, which preferably comprises a reflective stepped profile across a width of each of the elongated elements and which produces an effective blaze at a blaze angle. Alternatively, the blaze profile comprises a reflective surface angled at the blaze angle. Each of selected ones of the elongated elements comprise a first conductive element. The elongated elements produce the first diffraction when a first electrical bias is applied between the first conductive elements and a substrate.

Abstract: Novel structure of the optical elements (i.e. filter) to be operated in the long, mid, and near infrared wavelengths of lights is provided. The filter can offer very narrow linewidth, and high reflectivity (or transmissivity) at the peak wavelength. The optical element consists of the substrate, first diffraction grating and single uniform surface, and the second grating. Alternatively, the optical element again consists of the substrate, single uniform surface and the diffraction grating on the top of it. Alternatively, filter may also consist of number of sequence of layers, wherein each sequence comprises the single uniform layer sandwiched by the two diffraction grating layers. Filter again alternatively consists of the number of sequences wherein each sequence comprises the single uniform layer and the single diffraction grating. Diffraction grating may be two-step grating or multilevel grating with synchronously or nonsynchronously samples diffraction gratings.

Abstract: An optical system provides high-contrast operation by collecting zero order light. The optical system comprises a light modulator and a collector. The light modulator is preferably a grating light valve™ light modulator including a plurality of elements selectively operable in a first mode and a second mode, wherein a gap between adjacent elements is equal to or less than a wavelength of an incident light beam. The plurality of elements in the first mode reflect light along a return path, where the plurality of elements in the second mode direct light away from the return path. The collector is coupled to the light modulator to collect zero order light along the return path while the plurality of elements are in the first mode and to collect zero order light along the return path while the plurality of elements are in the second mode.

Abstract: An optical device and a display apparatus of the present invention are constructed so as to improve display characteristics of output light intensity, display contrast, and reduction of scattered light due to external light, and also to provide a large-screen. The optical device has a first stacked body and a plurality of second stacked bodies. The first stacked body includes a light guide, a first electrode, and an optical control layer. The second stacked body includes a plurality of second electrodes, the reflection film and a substrate. At least one of said first electrode and said second electrode has a periodic structure for inducing a fine periodic structure for light diffraction in said optical control layer.

Abstract: Integrated semiconductor waveguide gratings, methods of manufacture thereof and methods of apodizing thereof are described. A semiconductor waveguide grating includes a substrate, a cladding layer disposed on the substrate, a guide structure that includes a plurality of discrete transverse sections implanted with ions disposed between adjacent transverse sections substantially free of implanted ions.

Abstract: A tunable optical filter utilizes multiple electroholographic (EH) gratings with different center wavelengths to filter an optical signal over a wide wavelength range. The EH gratings are connected such that an input optical signal passes through at least one of the EH gratings. The EH gratings are activated and tuned by electrode pairs that are controlled through a voltage controller. The tunable optical filter is coarse tuned by activating the EH gratings having a wavelength range that includes the center wavelength that is to be filtered and fine tuned by adjusting the voltage that is applied across the activated EH gratings.

Abstract: A 2D diffraction grating light valve modulates an incident beam of light. A plurality of elements each have a reflective surface with their respective reflective surfaces substantially coplanar. Alternatively, the reflective surfaces of the plurality of elements lie within one or more parallel planes. The elements are supported in relation to one another. Preferably, a planar member includes a plurality of holes arranged in a symmetrical two-dimensional array and configured such that the holes substantially optically extend the elements. Alternatively, one or more elements substantially optically extends the plurality of holes. The planar member includes a light reflective planar surface that is parallel to the plane of the elements within a functional area of the device. The planar member is supported in relation to the elements. By applying an appropriate biasing voltage to the planar member, the planar member can be moved in a direction normal to the plane of the elements.

Abstract: A volume diffractive composite is disclosed for providing illumination at a first output angle. The volume diffractive composite comprises a first plurality of grating elements that are mutually spaced from another in a first position with a first spacing period along a first plane, and an actuation unit for changing at least one of the position or the spacing period of the first plurality of grating elements to a second position or spacing period to provide illumination at a second output angle.

Abstract: An optical device includes a planar subwavelength grating (10) formed in a dielectric material and having a laterally varying, continuous grating vector. When used to modulate a beam of laterally uniform polarized electromagnetic radiation incident thereon, the device passes the incident beam with a predetermined, laterally varying transmissivity and/or retardation. When used to effect polarization state transformation, the device transforms a beam of electromagnetic radiation incident thereon into a transmitted beam having a predetermined, laterally varying polarization state. The device (214) can be used to provide radially polarized electromagnetic radiation for accelerating subatomic particles or for cutting a workpiece. The device (108) also can be used, in conjuction with a mechanism for measuring the lateral variation of the intensity of the transmitted beam, for measuring all four Stokes parameters that define the polarization state of the incident beam.

Abstract: In a diffractive optical element, which is formed by laminating at least three layers of diffraction gratings made of at least three kinds of materials which differ in dispersion, at least three design wavelengths are set.

Abstract: An electro-mechanical grating device including: a base having a surface; a bottom conductive layer provided above said base; a spacer layer is provided and a longitudinal channel is formed in said spacer layer, wherein said spacer layer defines an upper surface and the channel having a first and a second opposing side wall and a bottom; a plurality of spaced apart ribbon elements disposed parallel to each other and spanning the channel, said ribbon elements are fixed to the upper surface of the spacer layer on each side of the channel and each of the ribbon elements is provided with a conductive layer; a mechanical stop provided between the bottom conductive layer and the bottom of the channel wherein the mechanical stop forms a rigid barrier that is separated from a lower ribbon surface of the ribbon elements by a distance h0.

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 (108). The introduction of the electronically reconfigurable diffraction grating (108), which is typically fabricated using MEMS (microelectromechanical systems) technology, improves the compact design, durability, and dynamic functionality of the WDM/DWDM system.

Abstract: A diffractive optical element for white light is composed of a plurality of layers of optical materials and has a relief pattern constituting a diffraction grating formed at least at one cementing interface between the two different optical materials. The grating height of the relief pattern constituting the diffraction grating is defined by the following formula: h=&lgr;/|n−n′| where h represents the grating height of the relief pattern constituting the diffraction grating; &lgr; represents the wavelength (here it is assumed that &lgr;≦450 (nm)); n represents the refractive index of the optical material abutting the interface from the object side for light of the wavelength &lgr;; and n′ represents the refractive index of the optical material abutting the interface from the image side for light of the wavelength &lgr;.

Abstract: The tunable optical filter includes an elastic substrate, a diffractive element in the elastic substrate, an actuator for stretching the elastic substrate to control the pitch of the diffractive element, a first optical path and a second optical path. The diffractive element optically couples the second optical path to the first optical path at an optical frequency determined by the pitch of the diffractive element.

Abstract: An optical MEM device is encapsulated with a dampening gas to reduce oscillatory vibrations of movable parts during the operation of the device. Preferably, the dampening gas comprises one or more noble gases, such as neon and/or krypton with a partial pressure in a range of 50 to 100% of the total dampening gas pressure. In further embodiments, the dampening gas comprises a mixture of one or more noble gases and an inert carrier gas, such as nitrogen. Preferably, the optical MEM device is sealed within a die with a dampening gas pressure between 0.5 to 3.0 atmospheres at 20 degree Celsius. The current invention is particularly useful for reducing oscillatory vibrations of optical MEM devices having a plurality of movable ribbon structures configured to modulate light with one or more wavelengths in the near infrared (800 to 4000 nanometers) and which operate at high switching rates (4-40 Volts/nano second) and at high switching frequencies (1 kHz and greater).

Abstract: In one embodiment of the invention, a grating structure etched on a mirror substrate has a grating period causing diffracting, out of an optical path, a first incident radiation within a first band around a first wavelength. A multi-layer coating deposited on the grating structure reflects the first incident radiation, in the optical path, within the first band and a second incident radiation within a second band around a second wavelength. In another embodiment, a first multi-layer coating deposited on a mirror substrate reflects a first incident radiation within a first band around a first wavelength and a second incident radiation, in an optical path, within a second band around a second wavelength. A grating structure is deposited on the first multi-layer coating. The grating structure is etched to have a grating period causing diffracting, out of the optical path, the second incident radiation within the second band.

Abstract: A tunable phase mask assembly for use in photoinducing an optical wavelength filter in an optical waveguide. The phase mask assembly includes a phase mask having a length extending between two opposite longitudinal ends. The phase mask has grating corrugations projecting from its surface and distributed with a periodicity along its length. The periodicity of the phase mask is tuned by reversibly changing its length between the two longitudinal ends, such as by compressing or stretching the mask. In this manner, the interference pattern of a light beam passing through the phase mask is also tuned, which allows to control the characteristics of a wavelength filter photoinduced using this phase mask assembly.

Abstract: A variable spacing diffraction grating is fabricated using micro-electromechanical (MEMS) technology. An array of interconnected beam elements is fabricated into a diffraction grating and mounted in such a manner that one or both ends of the array of beam elements may be actuated using a mechanical actuator. The beam elements may be linear, spiral shaped or arranged in a staircase structure. Applying a force to one or both ends of the array of beam elements changes the spacing of the grating, and presents a different ruling spacing distribution to incoming radiation, thus altering the diffracted angle among individual diffraction orders of the wavelength. Controlling the diffracted signal in this way allows for specific diffraction pass bands to be fixed on a particular detector or a particular area of a detector or optical relay lens or lenses.

Abstract: A light modulator includes elongated elements arranged parallel to each other and suspended above a substrate. The light modulator operates in a first diffraction mode and in a second diffraction mode. In the first diffraction mode, an incident light diffracts into a single diffraction order. Each of the elongated elements comprises a central blazed portion, a first outer blaze transition, and a second outer blaze transition. The central blaze portion, couples the first outer blaze transition to the second outer blaze transition. Each of the central blazed portions comprises a reflective surface. Selected ones of the central blazed portions comprise a first conductive element. The first outer blaze transition and the second outer blaze transition are coupled to the substrate.

Abstract: The methods and apparatus according to the invention equalize the power of at least one frequency in a multi-wavelength optical signal, or limit the power contained in a single or multi-frequency signal. More particularly, the optical power equalizer according to the invention is a filter with separably variable wavelength dependent transmission coefficients, wherein each coefficient decreases with increasing power for each respective wavelength coupled to the equalizer. Thus, the highest power wavelength output from an EDFA will be filtered more than the lower power wavelengths, making the output power from the EDFA more evenly distributed among the wavelengths. Such an equalizer can be placed downstream from each EDFA without destabilizing the optical network so that no changes need to be made to the EDFA or to the other components in the system.

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: A diffractive optical element includes a plurality of laminated diffraction grating surfaces. Each of the diffraction grating surfaces is formed to have a sufficiently small grating thickness as compared with a grating pitch thereof.

Abstract: A light valve of deformable grating type and a method for light modulation using the light valves is provided. The light valve of deformable grating type, includes at least three beams, one beam of the at least three beams being of a substantially fixed-position, and at least two beams of the at least three beams being deformable by electrostatic force in a substantially staircase structure, each step of the staircase creating a predefined change in the phase of an impinging light beam, a first electrode and a second electrode, the electrodes transmitting electrostatic force to at least the deformable beams of the at least three beams. The beam of a substantially fixed-position may be deformable by electrostatic force.

Abstract: A micromechanical reflection phase grating may be formed of spring-like ribbon reflectors that are secured to a transparent cover positioned over a substrate such as a silicon substrate. The ribbon reflectors are formed independently of the silicon substrate. If a defect occurs in the phase grating and particularly the ribbon reflectors, the top plate assembly can be reworked or discarded without sacrificing the relatively expensive silicon substrate.