Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to transmission of large volumes of data over long distances at high rates. An improved apparatus achieving precise dispersion compensation in a fiber span is disclosed. In particular, the invention teaches a configurable dispersion compensation trimmer with automatic detection of configuration.

Abstract: A wavelength selective optical switch of the present invention separates a WDM light emitted from an input port of an input and output optical system, according to wavelengths, by a diffraction grating, and thereafter, condenses the lights of respective wavelengths on MEMS mirrors respectively corresponding to the respective wavelengths, in a mirror array, to reflect them by a condenser optical system, to thereby switch optical paths for the respective lights. The condenser optical system is configured by combining a plurality of lenses whose focal distances are different from each other, and positions in an optical axis direction of the lenses are adjustable by a slide mechanism. Thus, despite an error in the focal distances of the condenser lenses, in a mounting angle of a spectral element or the like, a beam pitch at the condensing positions of the lights of respective wavelengths can be coincident with a mirror pitch in the mirror array.

Abstract: An optical connector (10) comprises at least one optical guide (12) for carrying optical radiations; a total internal reflection surface (11) upon which, in use, said radiations impinge, so that the radiation in the optical guide is reflected by said surface towards an optical element (14) of the connector and means enabling the connector (10) to interlock with any other optical connector which is appropriately matingly configured.

Abstract: A fiber coupler for coupling light into an optical fiber and/or coupling light out of the fiber, has two holder elements, namely a fiber holder for holding the fiber, and a lens holder for holding a focusing lens. The holder elements are adjustable in the axial and transversal direction, respectively. In order to make such a fiber coupler available, which allows precise adjustment of the position of the focusing lens relative to the fiber, and which is furthermore compact in structure and inexpensive to produce, the holder elements are connected with a base body by way of at least one elastic monolithic joint, in each instance.

Abstract: A domestic appliance includes a cover element, an optical operation indicator that can be covered by the cover element, and a fibre optic coupled to the optical operation indicator for transmitting a emitted light signal. The fibre optic has a light route along which light is guided, the light route being configured such that it can be adapted to the thickness of the cover element, and the fibre optic is composed a first part and a second part that are displaceable relative to one another. The relative displacement of the first part and the second part of the fibre optic permit adaptation of the light route to the thickness of the cover element.

Abstract: The present invention provides a memory element for providing compatibility information and/or parametric data about a scanning beam device to a universal base station. The present invention provides a memory coupled to the scanning beam device that provides parametric data, such as an identifier code, compatibility information, and other characteristics of the scanning beam device that is coupled to the universal base station. A controller of the base station may use the parametric data to configure or generate a control routine so as to allow the base station to properly operate the device.

Abstract: An improved waveguide shuttle optical switch design which provides the function of a variable optical attenuator (VOA). A small degree of intentional misalignment of the waveguide will create different levels of optical attenuation. By finely controlling the misalignment of a selected switched position, a single device may be realized that will provide the functions of both switching and attenuating or just attenuation alone. The optical MEMS device utilizes a latching mechanism in association with a thermal drive actuator for aligning a waveguide shuttle platform. The integration of the switching function and the VOA function reduce the optical loss which is otherwise unavoidable when the inevitable alternative of a separate switch and a separate VOA must necessarily be employed. The resultant improved device can also be applied for correcting the difference in optical intensity created by the manufacturing tolerances inherent in the fabrication of array waveguide gratings.

Abstract: An optical multiplexer that adjusts the wavelength response and compensates for temperature effects by using rotatable mirror. The wavelength response of the device is adjusted by aligning the mirror at a correct angle with respect to the surface terminating the optical waveguide grating. The temperature dependence of the index of refraction of the material comprising the waveguides is compensated for by rotating a reflecting surface of the mirror, the rotation based on differential thermal expansion. Some exemplary embodiments may comprise a slab waveguide on a substrate (the slab waveguide having a first and second arcuate end surfaces) attached to a submount, a mirror assembly rigidly attached to the submount (the mirror assembly comprising a first and second materials having different coefficients of thermal expansion), and an optical waveguide grating (upon the substrate attached to the submount) optically coupled between the second arcuate surface and the mirror assembly.

Abstract: An actuator system that includes two beams that are formed into a diamond pattern. A crossbar is positioned at a midsection to connect the two beams. When power is applied to the two beams, the diamond pattern is driven vertically. An actuator system may also include a substrate and a first layer above a second layer on the substrate. The first and second layers include upper and lower beams joined together at one end of the layers. A method of forming an actuator system includes forming a first layer above a second layer on a substrate, joining the first and second layers together at one end of the layers, and forming upper and lower beams. The upper and lower beams may be different in width, length and thickness to control a vertical movement of the actuator system.

Abstract: A nano-electromechanical optical switch includes an input optical waveguide that is provided with an optical signal. At least two output optical waveguides are coupled to the input optical waveguide. The deflection of the input optical waveguide aligns with one of either of the two output optical waveguides so as to allow transmission of the optical signal to one of either of the two output optical waveguides.

Abstract: An optical wavelength routing device utilizes a free space optical beam propagating therethrough is provided. The device includes at least one optical fiber input, at least one optical fiber output, an optical element having an actuator with at least one tilt axis and a diffraction element having a surface thereon. The device also includes an optical beam-splitting element having spatially varying optical properties. An optical beam transfer arrangement is positioned between the optical element and the diffraction element such that tilt actuation of the optical element elicits a proportional change in an angle of incidence of the optical beam onto the diffraction element, wherein the center of rotation for the angular change is the surface of the diffraction element. Optical routing between the fiber input and the fiber output can be configured by the positioning of the optical element.

Abstract: A frontlit touch panel for use with a reflective light valve, comprising a front light guide having at least one light input face that supplies light to the guide, a viewing face, a light output face opposite the viewing face, and at least one component of a touch-sensitive transducer, the light output face having a light extraction layer thereon having a substantially flat light exit face and containing buried reflective facets that extract supplied light from the guide through the light exit face. The touch panel can be used with a light source, reflective light valve and suitable control electronics to form a compact, efficient illuminated touch panel display assembly.

Abstract: A device for transmitting modulated optical signals between a first unit and a second unit, in which the first unit is supported to be rotatable or movable linearly relative to the second unit, comprises a light guide extending along a given track on the first unit, a first light coupler for coupling light into and out of the light guide, and a second light coupler disposed on the second unit and movable relative to the light guide for coupling light into and out of the light guide. A coupling slide is provided for supporting the second light coupler, and is mechanically loosely connected to the second unit via a take-up unit so that the coupling slide is moved along the given track together with the second unit by a movement of the second unit.

Abstract: A method for optical coupling an optical waveguide to an optical unit arranged in or on an optical module, a corresponding optical module, coupling element, and a kit of coupling elements is provided. The optical module has a reference geometry which defines a first axis of symmetry. Any offset between a first optical axis of the optical unit and the axis of symmetry of the reference geometry is determined. A coupling element corrects the offset and has an input/output area on opposite faces having offset second and third optical axes. Light input along the second optical axis is guided in the coupling element and output along the third optical axis, and vice versa. Once assembled, the center axis of the coupling element coincides with the axis of symmetry of the optical module, and the first optical axis of the optical unit and second optical axis of the coupling element coincide.

Abstract: The invention features an apparatus including a first portion defining an optical axis and configured to connect to an optical fiber, a second portion having a reference surface configured to connect with a terminal, and a third portion between the first and second portions. The third portion bends more easily than either the first or second portion to permit adjustable alignment of the optical axis relative to the reference surface.

Abstract: The present invention relates to an optical fiber magnetic scanning arrangement for a miniature optical fiber probe and can be applied for optical beam delivery in various optical imaging techniques. The arrangement is of the type where an optical fiber is rigidly fixed to a current conductor and serving as a flexible cantilever with a capability for the distal part of the optical fiber of being deflected in a direction substantially orthogonal to its own axis. New designs of the magnetic system are less critical to the shape and dimensional tolerances of scanner elements and assembly. These designs provide a potential for a less difficult assembly process and for further miniaturization. According to one aspect of the invention the permanent magnet system includes at least a first permanent magnet with a magnetization direction that is substantially aligned with the own axis of the optical fiber. The current conductor loop is placed adjacent to the one of the end faces of the first permanent magnet.

Abstract: An optical delay line for use with an optical source including input/output optics optically coupled to the optical source and a curved mirror with a reflective surface that is centered about an evolute curve of the delay line to retro-reflect light traveling along a delay line beam path tangent to the edge of the evolute curve. The input/output optics direct light from the optical source along the delay line beam path and direct delayed light from the delay line beam path out of the optical delay line along an output beam path. The input/output optics and/or the curved mirror rotate about the evolute curve at a selected angular speed. The reflective surface has a curvature based on a parametric curve that is calculated from the evolute curve such that the delay of the delay line varies according to a predetermined function as the input/output optics and/or the curved mirror rotate.

Abstract: A fiber optic rotary joint is provided that is unaffected by variations in the optical properties of a fluid that fills its internal cavity. The rotary joint includes a housing defining the internal cavity, first and second optical collimation arrays on opposite sides of the internal cavity, and a reversion prism between the optical collimation arrays. Further, the rotary joint includes an interface optical element proximate at least one of the first and second optical collimation arrays and the reversion prism. Each interface optical element includes an optically-flat surface adapted to contact the fluid such that optical signals that are oriented normal to the optically-flat surface can be transmitted without refraction, thereby rendering the optical signals immune to variations in the fluid's optical properties. A reversion prism assembly, an optical collimation assembly and a method of aligning an optical collimation array utilizing alignment pins are also provided.

Abstract: A display element is provided with a light source and a waveguide that propagates a light emitted from the light source, wherein the light propagated in the waveguide is extracted to outside from a waveguide lateral face, and wherein the light is extracted out of the waveguide from the waveguide lateral face by changing a shape of the waveguide lateral face.

Abstract: A system comprises at least one optical fiber that revolves around an axis when an array assembly that includes a radar array revolves around the axis. The optical fiber receives a light pattern that specifies information from the array assembly. A stationary device remains optically coupled to the optical fiber for receiving the light pattern while the optical fiber revolves around the axis.

Abstract: The present invention relates to an optical switch. The optical switch includes at least two binary control elements movable between a first and second position. The binary control elements include an at least one angle tuning element for adjusting the pathway of an optical signal. With a binary control element in the first position, the angle tuning element is able to adjust the pathway of an optical signal. With the binary control element in a second position, the angle tuning element is not able to adjust the optical pathway of an optical signal. The optical switch of the present invention can also concurrently switch multiple optical signals in parallel.

Abstract: An optical transceiver antenna has a pair of cartridges supported by a pan/tilt mount. A lens at forward end of a cartridge interfaces light between an end of a light relay element retained by an axial deflection device and free space. The forward end of a cartridge also terminates first ends of actuator wires that are mutually rotationally displaced a distance of 90° from one another in a plane normal to a boresight axis of the antenna. The actuator wires have second wire terminations at the axial deflection device which are mutually rotationally displaced a distance of 90° from one another in a plane passing through the axial deflection device normal to the boresight axis. Heating currents are supplied to the actuator wires, causing their lengths to change, thereby flexing the axial deflection device and light relay element off boresight.

Abstract: A rotatable connector comprises a plurality of optically conductive light rings adapted to mount to a first rotatable component; a plurality of light emitters for illuminating said light rings; a plurality of light detectors adapted to mount on a second rotatable component for detecting illumination of the photoconductive rings on the first rotatable component over a predetermined range of rotation.

Abstract: The invention comprises a method of connecting an integrated optical waveguide circuit component to an optical fiber array. The invention includes the steps of: providing an integrated optical waveguide circuit component having an array of N wave guide ports for optical processing that contain a subset of u-waveguides (one or more) structures for optimizing optical alignment; providing an optical fiber array having an array of at least N optical fibers, and positioning the optical fiber array adjacent to the circuit component so that photons emitted from the optical fiber array ports are coupled into the respective individual corresponding u-waveguide port(s) and then back into the corresponding optical fiber coupling ends of the optical fiber array.

Abstract: A fiber tip fluid output device is provided for holding a fiber tip in an electromagnetic energy cutting apparatus and for directing water particles over a radiation delivery end of the fiber tip. The fiber tip fluid output device includes a generally cylindrical body having an outer surface, a proximal end, a distal end, and a lumen extending between the proximal end and the distal end. The lumen is sized and shaped to accommodate a fiber tip therethrough so that the fiber tip extends through the lumen from the proximal end to the distal end of the generally cylindrical body. The fiber tip fluid output device further includes a plurality of apertures extending around the generally cylindrical body, with each of the apertures of the plurality of apertures fluidly connecting the outer surface to the lumen. Fluid is mixed around the cylindrical body, before entering the lumen through the plurality of apertures for additional mixing.

Abstract: Electrets are used in a variety of MEMS-based actuator devices. The electret is able to store electrical charge for a long time with negligible charge leakage. Therefore, when an electret is incorporated into a MEMS device that requires actuation, the device can be initially biased to any desired actuation state for a long period of time without the use of external bias voltages. Such a MEMS-based device may include a MEMS-based actuator having at least a first deflectable member and at least a second member. The first deflectable member and the second member are provided with a floating electrode and a second electrode. A charge on the first floating electrode is selected so as to position the first deflectable member at a desired separation distance from the second member. The device may be used to align an optical component or to change the electrical characteristics of an electrical element.

Abstract: As a wavelength selection filter, a filter in which dielectric multilayered films are formed on a substrate, an optical fiber grating in which diffraction grating is formed in an optical fiber, and so on, can be used. As another optical demultiplexer 33, as described in Japanese Patent No. 2599876, an arrayed optical waveguide diffraction grating which forms plural optical waveguides having different length of optical paths on the substrate to demultiplex the multiple wavelength light to the respective wavelengths can be used.

Abstract: A single-sided optical switching device for functioning as a dual switch wherein individual switches share common switching means is disclosed. The individual switches have separate ports and share common switching means formed by a moveable refractor, a single lens and a stationary reflector, wherein the movable refractor is positionable between the lens and the stationary reflector for redirecting light within ports of individual switches. An embodiment of the device provides a single-sided dual 2×2 bypass switch comprising a single lens and a single switching element.

Abstract: A two-dimensional optical deflector includes a first deflector, which deflects a light beam about a first axis at a high speed, a second deflector, which deflects a light beam about a second axis perpendicular to the first axis at a low speed, and a fixing mechanism, which fixes the first deflector to the second deflector. The second deflector includes a rotation shaft capable of rocking about the second axis. The fixing mechanism includes a fixing member having a rotation shaft fixing hole, which engages with the rotation shaft with almost no space, and a fastener, which decreases the diameter of the rotation shaft fixing hole of the fixing member. The fixing member includes a first deflector mount surface. The first deflector is fixed to the fixing member so that a reflecting surface of the first deflector in a non-actuation state is almost parallel to the first deflector mount surface.

Abstract: An apparatus for selectively coupling fiber optic lines comprises an optical input selection device, an optical output selection device, and a rotatable coupling mechanism interconnecting the optical input selection device and the optical output selection device. The optical input selection device is rotatable about a first central axis, and comprises a first input end and a first output end. The first input end is disposed collinearly with the first central axis, and the first output end is disposed at a radially offset distance from the first central axis. The optical output selection device is rotatable about a second central axis, and comprises a second input end and a second output end. The second input end is disposed at a radially offset distance from the second central axis, and the second output end is disposed collinearly with the second central axis. Rotation of the coupling mechanism causes rotation of the first output end and the second input end.

Abstract: A device for transmitting modulated optical signals between units comprises a first unit and a second unit, the first unit being supported to be rotatable with respect to the second unit, a light guide along a circular track on the first unit, a first and a second light coupler for coupling light signals into or out of the light guide, the second light coupler being disposed on the second unit and movable with respect to the light guide. For an achievement of a high transmission bandwidth, a controllable absorber is provided in the light guide to prevent a propagation of light along a plurality of paths between the two units. In a method for operating the device, the absorber is controlled so that modulated light signals from the first and the second directions have a same amplitude at a point at which the modulated light signals have the same phase.

Abstract: A system is described for providing selectable delay. A first converter converts a first electromagnetic signal into an optical signal. An optical switch is coupled to the first converter to provide selectable delay by selection of paths by a plurality of movable microelectromechanical system (MEMS) mirrors. The paths have respective measurable differences in delay for the optical signal. A second converter coupled to the optical switch converts the optical signal into a second electromagnetic signal. The differences in delay for the optical signal result in differences to delay for the second electromagnetic signal in comparison to the first electromagnetic signal. Relatively short delays are provided by the optical switch and relatively long delays are provided by a plurality of fiberoptic delay lines.

Abstract: An optical coupling and a method of making an optical coupling where the alignment of the optical beam between two optical ports is completed after the optical coupling is assembled or packaged for shipment through the repositioning of a collecting mirror which is interposed to intercept an optical beam from an optical beam transmitter and then reflect the optical beam onto an optical beam receptor without an operator having to move or align either the optical beam transmitter or the optical beam receptor.

Abstract: The directional coupler switch is configured by a parallel waveguide including a first region which is subjected to a nonlinear action and a second region which is not subjected to a nonlinear action. A dispersion relationship of the first region is varied due to the nonlinear action to switch over an exit of light entering from an input side to cause the switch to function as an optical switch. A dispersion curve of the first region has: a region of a constant frequency in one of an even mode and an odd mode which are two kinds of eigen modes of the parallel waveguide; and a region in which gradients of the two eigen modes at frequencies belonging to a region other than the region of a constant frequency are substantially equal to each other. The gradients of the two kinds of eigen modes indicate monotone decreasing or monotone increasing.

Abstract: A scanning apparatus and method, the apparatus comprising: a light transmission means (90) having an exit tip; first and second drive means (92,94) for resonantly driving the light transmission means (90) in orthogonal directions; wherein the first and second drive means (92,94) are operable to move the tip in an elliptical pattern while varying the eccentricity of the elliptical pattern, whereby a portion of the elliptical pattern having a centre on the minor axis of the elliptical pattern approximates—at least in appearance—a raster pattern.

Abstract: A display device and method of operating the display device. The display device comprising a support substrate, a plurality of ring or disk shaped light emitting light emitting resonators placed in a matrix on the support substrate forming a plurality of rows and columns of the light emitting resonators, each of said light emitting resonators having photo-luminescent lumiphore placed in the outer portion of said ring or disk shaped light emitting resonators A plurality of light waveguides positioned on the substrate such that each of the light emitting resonators is associated with an electro-coupling region with respect with to one of the plurality of light waveguides and a deflection mechanism for causing relative movement between a portion of at least one of the plurality of light waveguides and the associated light emitting resonator so as to control when the light emitting resonator is in the electro-coupling region.

Abstract: An optical device according to an embodiment of the present invention has an actuator structure. The actuator structure has a substrate, a stationary electrode, a movable electrode, an optical element, and a hole portion. The stationary electrode is provided on a surface of the substrate. The movable electrode is provided on the surface of the substrate. The optical element is provided on the movable electrode. The substrate faces the movable electrode. The hole portion is formed in a part of the substrate. A region near the movable electrode where the optical element is provided is immersed in a matching oil.

Abstract: A laser based ignition system for stationary natural gas engines, a distributor system for use with high-powered lasers, and a method of determining a successful ignition event in a laser-based ignition system are provided. The laser based ignition (LBI) system for stationary natural gas engines includes a high power pulsed laser providing a pulsed emission output coupled to a plurality of laser plugs. A respective one of the plurality of laser plugs is provided in an engine cylinder. The laser plug focuses the coherent emission from the pulsed laser to a tiny volume or focal spot and a high electric field gradient at the focal spot leads to photoionization of the combustible mixture resulting in ignition.

Abstract: Provided is a wavelength tunable optical filter of a micro-electro-mechanical system (MEMS). The wavelength tunable optical filter comprises two optical fibers or optical waveguides having their optical axes aligned to each other, two lens for collimating light at leading ends of the optical fibers or optical waveguides, two or more mirrors formed on a substrate, thermal actuators supporting at least one of the mirrors, wherein one of the mirrors is actuated by thermal expansion of the actuator. Because all mirrors are formed on a substrate, a manufacturing process is simple and an initial resonance wavelength can be precisely adjusted. Since the thermal expansion is generated by the electrical current directly flowing through the thermal actuators, it can be actuated by a low consumption power. Also, since an electrostatic force is not used to move the mirrors, a sticking phenomenon between the mirrors does not occur, and the wavelength can be tunable in a wide range.

Abstract: In one aspect of the invention, a gain equalizer comprises a wavelength division demultiplexer operable to separate one or more communication bands into a plurality of wavelengths and an array of phase shifter stages. Each phase shifter stage comprises a micro-electro-optic system (MEMS) device comprising a moveable mirror layer operable to receive a first copy of an input signal from a beam splitter and to reflect the first copy of the input signal for combination with a second copy of the input signal at an output to form an output signal. The moveable mirror layer is displaceable in a substantially piston-like motion to introduce a phase shift between the first and second signal copies at the output, the amplitude of the output signal varying depending on the displacement of the moveable mirror layer.

Abstract: A display device and method of operating the display device.

Abstract: To steer a beam in an optical switch, a collimator joined to an optical fiber along a Z-axis is mounted in a gimbal for rocking movement about X and Y axes. A piezoelectric actuator extends along the Z-axis and is symmetric about the fiber. An angular position sensor on the collimator provides feedback for use in steering the beam.

Abstract: An optical device has a rotatable birefringent crystal. The crystal is rotatable around a first axis (4; 42) and has a crystallographic-optical axis (6; 44) in a plane that is perpendicular to the first axis. In addition, the crystal is rotated around the first axis in order to control a displacement (?x) of a light beam in the plane when the light beam is polarized within the plane and directed onto the crystal.

Abstract: The present invention is a piezoelectrically actuated relay that latches. The relay operates by means of the longitudinal displacement of a piezoelectric element in extension mode. The piezoelectric element displaces a liquid metal drop and causing it to wet between at least one set of contact pads and at least one other set of contact pads. Positioning of the liquid metal causes the optical path to be blocked. The same motion that causes the liquid metal drop to change position can cause the optical path to be unblocked between the fixed pad and a contact pad on the piezoelectric element or substrate close to it. The motion of the piezoelectric element is rapid and causes the imparted momentum of the liquid metal drop to overcome the surface tension forces that would hold the bulk of the liquid metal drop in contact with the contact pad or pads near the actuating piezoelectric element. The switch latches by means of surface tension and the liquid metal wetting to the contact pads.

Abstract: An optical fiber having a reduced cross-sectional region adjacent to its distal end, which is fused to an optical component, is vibrated, rotating the optical component to scan a region. The optical component has a back focal point that is substantially coincident with an effective light source of the optical fiber, so that the light emanating from the optical component is either substantially collimated or convergent. The optical component is either a ball lens, a drum lens, a graded index lens, or a diffractive optical element. A vibratory node is also made substantially coincident with the back focal point of the optical component, producing a compact scanner with extensive field of view. The optical fiber is preferably reduced in cross-sectional area after the optical component is fused to the optical fiber, by immersion in a three-layer etch apparatus having an etch-stop layer, an etch layer, and a solvent layer.

Abstract: A coupler assembly for an optical backplane system having a backplane and two or more circuit packs connected to that backplane. Each circuit pack has an optical transceiver and the backplane has an optical pipe (e.g., an array of waveguides) adapted to guide optical signals between the transceivers of different circuit packs. A coupler assembly is provided for each transceiver to couple light between that transceiver and the optical pipe. Advantageously, the coupler assembly has a movable optical element that can accommodate possible misalignment between the backplane and the circuit pack. In one embodiment, the movable optical element is an array of MEMS mirrors, each mirror adapted to direct light between an optical transmitter or receiver and the corresponding waveguide of the optical pipe.

Abstract: The invention is to offer an optical device which is capable of reducing the insertion loss comparing with a conventional one. The optical switch comprises a fiber collimator for input an light beam, a fiber collimator for output the light beam to the outside, an optical path switching element, an optical path switching element as well as a slider arranged in the optical paths between the fiber collimator and the fiber collimator to change the light path and the optical characteristics, a solenoid actuator for moving the slider, a guide mechanism for guiding the slider as the slider moves, a magnet for generating a magnetic field, the magnet being arranged at a position where the slider is pressed against the guide mechanism by means of a magnetic force of a magnetic field generated by the magnet.

Abstract: Described are various optical, opto-electrical and electrical components and subsystems. Some embodiments include input and output waveguides supporting opposing facets separated by a gap. The degree to which the opposing facets are aligned with respect to one another controls the light intensity in the output waveguide. An active closed-loop control mechanism dynamically controls the extent of waveguide alignment to maintain a desired output intensity. In other embodiments, the path between opposing facets can be selectively blocked by a micro blade. Still other embodiments combine switching with optical power equalization for ease of integration.

Abstract: An integrated device of the present invention comprises free-space optics, a bi-directional multiplexor/de-multiplexor, a diffractive light modulator, a beam splitter, an optical performance monitor, and a controller. The free-space optics collimate, transform and image optical signals including a range of component wavelength signals. The bi-directional multiplexor/de-multiplexor de-multiplexes a wavelength division multiplexed signal into the component wavelength signals and multiplexes equalized component wavelength signals into an equalized wavelength division multiplexed signal. The diffractive light modulator selectively equalizes each component wavelength signal. The beam splitter is optically coupled in free-space to the diffractive light modulator for receiving the equalized component wavelength signals and re-directing a representative portion of each of the equalized component wavelength signals.

Abstract: An optical attenuator for attenuating a collimated beam of light propagating along an optical path while preserving the composition of polarization of the collimated beam of light is disclosed. The optical attenuator comprises a beam attenuator for attenuating a portion of the collimated beam of light when a portion of the beam attenuator is disposed within the optical path. The beam attenuator has a cross section along a plane perpendicular to the direction of propagation of the collimated beam of light of the portion of the attenuator in the shape of a wedge. The attenuation is varied using a controller for moving the beam attenuator in order to vary a size of the portion of the wedge within the optical path.