Abstract: A system includes a radiation source, first and second phased arrays, and a detector. The first and second phased arrays include optical elements, a plurality of ports, waveguides, and phase modulators. The optical elements radiate radiation waves. The waveguides guide radiation from a port of the plurality of ports to the optical elements. Phase modulators adjust phases of the radiation waves. One or both of the first and second phased arrays form a first beam and/or a second beam of radiation directed toward a target structure based on the port coupled to the radiation source. The detector receives radiation scattered by the target structure and generates a measurement signal based on the received radiation.

Abstract: An electrochromic device having a conductive layer having reflectiveness and light absorption characteristics simultaneously. The device is capable of realizing various esthetic senses, color senses or stereoscopic color patterns, and at the same time has excellent durability.

Abstract: A beam deflector and a holographic three-dimensional image display apparatus employing the same are provided. The beam deflector deflects light through two stages by a first beam deflector that deflects the light in a first moving direction making an angle with a horizontal direction and a vertical direction, such that the deflected light is oriented to a first location, and a second beam deflector that deflects the light incident from the first beam deflector such that the light is deflected in a second moving direction making an angle with the horizontal direction and the vertical direction at the first location and is oriented to a second location.

Abstract: This disclosure includes variable light transmission panels (VLTPs) and their assembly into insulated glass units (IGUs), which can be incorporated into buildings. Disclosed windows provide uniform appearance from outside during the day when a number of such windows are incorporated in a building regardless of their state of light transmission. These disclosures may also be used to make windows which tint to different transmitted colors but during the day still appear to be uniform from outside.

Abstract: An optical system comprising: an optical element having an optical property responsive to an applied signal, a variation of the optical property with the signal exhibiting hysteresis in a first range of values and no hysteresis in a second range of values of the signal; a memory storing data representing a hysteresis curve which indicates the variation of the optical property with increasing and decreasing values of the signal; and a controller which continuously controls the optical property by: generating, based on the stored data, a cyclic signal having a discontinuity in each cycle of the cyclic signal, and setting the discontinuity size in each cycle based on the stored data such that a part of the variation of the optical property with the cyclic signal coincides with a part of the variation represented by the stored data; and applying the cyclic signal to the optical element.

Abstract: An example system includes a bulk steering crystal apparatus having a first lens face and a second concave face. The example bulk steering crystal apparatus further includes a number of steering portions interposed between the first lens face and the second concave face, where each of the steering portions includes a bulk substrate portion including an electro-optical material and a corresponding high-side electrode electrically coupled to the corresponding one of the number of steering portions.

Abstract: A reflective-type display screen and a control method thereof, and a display device are provided. The reflective-type display screen comprises, a display panel, a compensation light source, a detector module and a processor module. The display panel comprises a reflection surface, the display panel is configured to reflect light by the reflection surface to realize display; the compensation light source is in the display panel; the detector module is on a light-outputting side of the display panel and is configured to acquire an intensity of ambient light outside the display screen; and the processor module is respectively connected with the detector module and the compensation light source and is configured to control operation of the compensation light source based on the intensity of the ambient light acquired by the detector module.

Abstract: Structures for an optical power modulator and methods of fabricating a structure for an optical power modulator. A waveguide core includes a longitudinal axis, a first section, and a second section spaced from the first section along the longitudinal axis. An active layer includes a portion positioned along the longitudinal axis between the first section and the second section of the waveguide core. The active layer contains a material configured to have a first state with a first refractive index in response to an applied stimulus and a second state with a second refractive index different from the first refractive index.

Abstract: An optical endless phase shifting device includes a Mach-Zehnder structure operated in push-pull configuration and that creates a differential phase shift. The first stage outputs combined signals which are phase shifted by a phase shift of zero or ? in the second stage by phase shifters provided in both arms of the second stage or in a first arm only. These additionally phase-shifted signals are combined to at least one output signal. A control device controls the phase shifters such that endless shifting capability is provided by switching one of the phase shifters or the single phase shifter of the second stage to the respective other value when the differential phase shift reaches a given range of the differential phase shift of [0;?/2] in the configuration with two phase shifters in the second stage or [0;?/2] in the configuration with only one phase shifters in the second stage.

Abstract: A MEMS element includes a substrate, a fixing portion provided at the substrate, first and second actuators provided at the fixing portion, a drive target member coupled to the first and second actuators, a third actuator provided at the fixing portion, and a restriction member coupled to the third actuator. The first and second actuators drive the drive target member in a direction parallel to or crossing an upper surface of the substrate. The third actuator drives the restriction member in a direction crossing a movement direction of the drive target member to position the restriction member within a movement plane of the drive target member such that the restriction member restricts displacement of the drive target member.

Abstract: Techniques for automatically determining an input resistance of an optical modulator and configuring a modulation current source can include applying a first bias current to an input of the optical transmitter and measuring a corresponding first voltage at the input of the optical transmitter. A second bias current can also be applied to the input of the optical transmitter and a corresponding second voltage at the input of the optical transmitter can be measured. An input resistance of the specific optical transmitter can be determined from the difference between the first and second voltages divided by the difference between the first and second bias currents. The technique can further include setting one or more configuration settings in one or more registers of a modulation current source based on the determined input resistance of the optical transmitter.

Abstract: An optical waveguide element and control method thereof, a backlight module and a display device. The optical waveguide element includes a cavity, a light incident surface and a light emergent surface, light entering the cavity from the light incident surface is configured to propagate and be totally reflected in the cavity; and a reflector array, located in the cavity and configured to be controllable to cause at least a part of the light incident on the reflector array to be reflected out of the light emergent surface or to continue being totally reflected at the light emergent surface.

Abstract: An electrochromic element includes: a first electrode; a second electrode; a peripheral sealing seal arranged between the first electrode and the second electrode; and an electrochromic layer arranged in a space demarcated by the first electrode, the second electrode, and the peripheral sealing seal, one of the first electrode and the second electrode is an anode electrode, and the other is a cathode electrode, the electrochromic layer is an electrochromic element having an anodic electrochromic compound and a cathodic electrochromic compound, the peripheral sealing seal is an anodic reaction-preferential peripheral sealing seal in which an oxidation reaction of the anodic electrochromic compound preferentially occurs near the peripheral sealing seal, and SA<SC, where SA is an area demarcated by the peripheral sealing seal of the anode electrode, and SC is an area demarcated by the peripheral sealing seal of the cathode electrode.

Abstract: Provided is an optical transmitter having improved frequency characteristics by controlling the band by using components constituting the optical transmitter. An optical transmitter including an optical modulator that includes a traveling-wave electrode and a terminating resistor, and an optical modulator driver configured to drive the optical modulator, in which a characteristic impedance of a transmission line connecting the optical modulator driver and the optical modulator is 20% or more higher than a characteristic impedance of the optical modulator, and an electrical length of the transmission line is 1/20 or more and ½ or less of a wavelength corresponding to a 3 dB band frequency of an electrical signal driving the optical modulator.

Abstract: An example system includes a bulk steering crystal apparatus having a first lens face and a second concave face. The example bulk steering crystal apparatus further includes a number of steering portions interposed between the first lens face and the second concave face, where each of the steering portions includes a bulk substrate portion including an electro-optical material and a corresponding high-side electrode electrically coupled to the corresponding one of the number of steering portions.

Abstract: A micro-LED laser display having an array of display pixels includes a display substrate for displaying an image and an array of display pixels. Each display pixel has one or more micro-LED lasers disposed on the display substrate. Each micro-LED laser emits light within an emission angle. One or more light spreaders for increasing the emission angle of light emitted by each micro-LED laser are disposed in relation to the light spreaders and a controller individually controls the micro-LED lasers.

Abstract: An optical transceiver including a submount, a Mach-Zehnder Modulator (MZM), bonding wires, and a low pass filter type matching network is provided. The MZM includes an input port and an output port and disposed on the submount. The bonding wires are coupled to the submount and the MZM. The low pass filter type matching network is coupled to the bonding wires and is configured to absorb inductance of the bonding wires at a high frequency.

Abstract: A device and a head-mounted display (HMD) are provided. The device comprises a first flexible electrode and a second flexible electrode configured to provide a driving voltage to the device; a birefringent material layer coupled to the first flexible electrode and the second flexible electrode, and structurally patterned to provide at least one predetermined optical function of the device; and a first photo-alignment (PAM) layer and a second PAM layer sandwiching the birefringent material layer. A structured pattern of the birefringent material layer is based on a manipulation of optic axis of birefringent material molecules in the birefringent material layer.

Abstract: Using two uniaxial optical crystals of trigonal 3 m symmetry, and with their optical axes aligned perpendicular to each other, a fast spatial light switch is disclosed based on changing the refractive index and optical axes of one of the crystals using Pockels effect. The first crystal in which Pockels effect is induced has electrodes along top and bottom sides. The interface between the crystals is at an angle such that the beam of light is totally reflected out of the first crystal. When an electric field is impressed through the first crystal, its refractive indices and crystal axes are altered such that the interface becomes transmissive, with the beam exiting from the second crystal. Spatial separation of Transmissive and Reflective States provides >50 dB of Cross-talk and Extinction ratios.

Abstract: The disclosure relates to a method for manufacturing recessed micromechanical structures in a MEMS device wafer. First vertical trenches in the device wafer define the horizontal dimensions of both level and recessed structures. The horizontal face of the device wafer and the vertical sidewalls of the first vertical trenches are then covered with a self-supporting etching mask which is made of a self-supporting mask material, which is sufficiently rigid to remain standing vertically in the location where it was deposited even as the sidewall upon which it was deposited is etched away. Recess trenches are then etched under the protection of the self-supporting mask. The method allows a spike-preventing aggressive etch to be used for forming the recess trenches, without harming the sidewalls in the first vertical trenches.

Abstract: Phase imbalance between in-phase (I) and quadrature (Q) components of an optical communications signal causes signal degradation that can result in degraded bit-error rate performance, increased power requirements, and reduced transmission distance. The signal degradation can be expressed as a reduced signal to noise and interference ratio. The disclosed system and techniques monitor the phase imbalance between the I and Q channels and provides for adjustment of the phase of one or more of the I and Q channels to improve overall performance.

Abstract: A display device with high visibility or low power consumption is provided. The display device includes a self-luminous display element and a reflective display element. The reflective display element includes a light-reflective layer and a liquid crystal material. The self-luminous display element transmits visible light. The liquid crystal material is located between the light-reflective layer and the self-luminous display element. The display device further includes a polarizing plate located between the liquid crystal material and the self-luminous display element. Alternatively, the self-luminous display element is preferably located between the liquid crystal material and the polarizing plate. The display device further preferably includes one or more coloring films located between the liquid crystal material and the self-luminous display element.

Abstract: A single drive type optical modulator has good high-frequency characteristics and reduced wavelength chirp of the modulated light. An optical modulator is provided with a Mach-Zehnder optical waveguide including first and second optical waveguides, a buffer layer covering the first and second optical waveguides, and an electrode layer including first and second ground electrodes and a signal electrode positioned between the first and second ground electrodes in a plan view. The signal electrode has a first lower surface covering the first optical waveguide through the buffer layer, the first ground electrode has a first lower surface covering the second optical waveguide through the buffer layer and a second lower surface positioned above the first lower surface, and a gap between the signal electrode and the second ground electrode that is larger than a gap between the signal electrode and the first ground electrode.

Abstract: The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-generation (4G) communication system such as long term evolution (LTE). According to various embodiments of the present disclosure, an apparatus in a wireless communication system comprises an antenna array configured to steer a first beam using antenna elements, and a lens including a first focal point and a second focal point. The lens is configured to generate a second beam of a plane wave by compensating for a phase error of the steered first beam passing through at least one of the first focal point or the second focal point.

Abstract: The present invention discloses a GSG track-type radio-frequency electrode, a silicon-based traveling-wave electrode light modulator, and a preparation method, and relates to the field of high-speed electro-optical chips. The GSG track-type radio-frequency electrode includes a GSG-type planar electrode, where a track electrode used for delaying an electric field is periodically added to one side or dual sides of the GSG-type planar electrode, and the track electrode is connected to a ground electrode of the GSG-type planar electrode. The silicon-based traveling-wave electrode light modulator includes the GSG track-type radio-frequency electrode and a conventional silicon-based traveling-wave electrode light modulator, and the GSG track-type radio-frequency electrode is connected to an active region of the silicon-based traveling-wave electrode light modulator by using through holes between electrode layers.

Abstract: In one aspect, the present disclosure relates to a self-identifying optical transmitter for broadcasting a one-way authentication code using light-based communication. The transmitter may include a memory for storing an identifier of the transmitter, a processor for generating a data signal including an identifier of the transmitter, a modulator for receiving the data signal and generating an electrical signal, the modular generating the electrical signal by modulating the data signal. The transmitter may also include a light source for receiving the electrical signal, converting the electrical signal into an optical signal, and continuously broadcasting the optical signal as an optical data transmission stream. The optical data transmission stream may be used to verify that a receiving mobile device is near the transmitter. The transmitter may also include an optical surface for dispersing the optical data transmission stream as the optical data transmission stream is emitted from the transmitter.

Abstract: A visual display unit creating a three-dimensional volumetric space. The display includes a first screen in a first focal plane, wherein the first screen displays a first image. The display includes a second screen in a second focal plane distinct from the first focal plane, wherein the second screen displays a second image, and wherein the second screen at least partially overlaps the first screen. The display includes a physical object located between the first screen and said second screen, wherein at least one of the first and second images is displayed in response to a placement of the physical object.

Abstract: An optical device includes one or more light sources and a light-guiding plate that guides light emitted from the light sources in a plane parallel to an emission surface that emits light. The light-guiding plate has light convergence portions that receive guided light and each have optical surfaces that cause light to be emitted from the emission surface in directions in which the light substantially converges at or scatters from one convergence point. The convergence points for the light convergence portions are different from each other. An image is formed on an emission surface side by a collection of the convergence points. First light convergence portions positioned differently from each other along a light-guiding direction of the light-guiding plate cause light to be emitted from the emission surface in different directions in which the light substantially converges at or scatters from the same first convergence point among the convergence points.

Abstract: The present invention provides a liquid crystal lens and a 3D display device. By utilizing the metal wire grid (20) to realize the functions of electrode and polarizer at the same time, and the polarizer filters the o light to solve the display degradation issue due to the o light leakage, and corresponding high quality 3D image display is realized. By combining function of the polarizer and the electrode in the metal wire grid (20), the additional polarizer adhesion is no longer required, which can effectively decrease the thickness of the liquid crystal lens. The present invention further provides a 3D display device, which can decrease the thickness of the 3D display device to realize the high quality 3D image display.

Abstract: An inorganic light-emitting diode (iLED) pixel structure includes a transparent pixel substrate having an LED surface, an emission surface opposite the LED surface, and one or more sides other than the LED surface and the emission surface that are not parallel to the LED surface or the emission surface. One or more iLEDs are mounted on the pixel substrate and each iLED has an emission side adjacent to the LED surface of the pixel substrate to emit light into the pixel substrate and out of the emission surface. A reflector is disposed on at least a portion of the one or more sides.

Abstract: This disclosure provides connectors for smart windows. A smart window may incorporate an optically switchable pane. In one aspect, a window unit includes an insulated glass unit including an optically switchable pane. A wire assembly may be attached to the edge of the insulated glass unit and may include wires in electrical communication with electrodes of the optically switchable pane. A floating connector may be attached to a distal end of the wire assembly. The floating connector may include a flange and a nose, with two holes in the flange for affixing the floating connector to a first frame. The nose may include a terminal face that present two exposed contacts of opposite polarity. Pre-wired spacers improve fabrication efficiency and seal integrity of insulated glass units. Electrical connection systems include those embedded in the secondary seal of the insulated glass unit.

Abstract: An optical transmission method wavelength-multiplexing and transmitting multiple channels including data. The data are composed of data areas independent between the channels and data areas non-independent between the channels. Data patterns of the data areas non-independent between the channels are variable. The data patterns of the data areas non-independent between the channels are set so that in time periods of the non-independent data areas on an optical transmission section, a time period during which polarization states of the multiple channels are correlated in the optical transmission section has a length such that an error rate is less than or equal to a threshold value, the error rate being determined from a temporal distribution of bit errors obtained from a result of error decision after demodulation in an optical receiver.

Abstract: A segmented traveling wave Mach Zehnder optical modulator is described. The segmented traveling wave Mach Zehnder optical modulator may comprise two or more radio frequency (RF) segments, and each RF segment may be configured to support a modulating RF signal. The modulating RF signals may be configured to modulate an optical signal propagating along an optical path of the segmented traveling wave Mach Zehnder optical modulator. The RF modulating signal in the second RF segment may be generated by amplifying the modulating RF signal of the first RF segment, using an RF amplifier. The RF amplifier may be configured to amplify a band-pass spectral portion of the modulating RF signal.

Abstract: Disclosed is an apparatus for controlling tint of a display panel provided on a vehicle window to adjust light transmittance depending on ambient light conditions, thereby overcoming difficulties in securing a clear view, such as glare caused by sunlight or high-beam headlamps of a vehicle in the opposite direction lane during driving. The apparatus includes: a display panel film attached to a window glass of the vehicle, and having an adjustable tint; an operation unit setting the tint of the display panel film; a detection sensor unit quantifying a change in an external environment into data; and a control unit adjusting the tint of the display panel film according to a preset program by using the data received from the detection sensor unit.

Abstract: Methods and systems for controlling the phase of electromagnetic waves are disclosed. A device can consist of a guided resonance grating layer, a spacer, and a reflector. A plurality of devices, arranged in a grid pattern, can control the phase of reflected electromagnetic phase, through refractive index control. Carrier injection, temperature control, and optical beams can be applied to control the refractive index.

Abstract: A structure for coupling an optical signal between an integrated circuit photonic structure and an external optical fiber is disclosed as in a method of formation. The coupling structure is sloped relative to a horizontal surface of the photonic structure such that light entering or leaving the photonic structure is substantially normal to its upper surface.

Abstract: A maskless exposure device including a light source configured to emit an exposure beam, a light modulation element configured to modulate the exposure beam according to an exposure pattern, a projection optical system configured to transfer a modulated exposure beam to a substrate as a beam spot array, a beam measurement part configured to measure a beam data of the beam spot array, and a compensating mask generator configured to generate a compensating mask by utilizing a measured data of the exposure beam for compensating cumulative illumination, wherein the compensating mask generator is configured to turn off left and right beams of a first selected spot beam selected by the beam data, and then to turn off a second selected spot beam.

Abstract: An optical module includes an optical modulator that modulates light by using an electrical signal input from a first surface to a plurality of electrodes; and a flexible substrate that has a plurality of wiring patterns electrically connected to the plurality of electrodes, respectively, on the first surface. The optical modulator has a bulging part that bulges out from the first surface opposed to the flexible substrate toward the flexible substrate and is in contact with the flexible substrate.

Abstract: A nonvolatile memory storage device includes a ferroelectric (FE) material coupled with a piezoresistive (PR) material through an inherent piezoelectric response of the FE material, wherein an electrical resistance of the PR material is dependent on a compressive stress applied thereto, the compressive stress caused by a remanent strain of the FE material resulting from a polarization of the FE material, such that a polarized state of the FE material results in a first resistance value of the PR material, and a depolarized state of the FE material results in a second resistance value of the PR material.

Abstract: This disclosure provides systems, methods and apparatus for providing compact shutter assemblies. Shutter assemblies can be formed in a more compact fashion, allowing for higher pixel-per-inch displays, by incorporating shutters that during actuation pass over or under portions of the actuators that control those shutters.

Abstract: A method of optical signal amplification. Incident photons are received at a photodetector including a doped semiconductor biased by a power source. The photons generate a change in a reflective property, refractive index, or electrical conductivity of the doped semiconductor. For the change in reflective property or refractive index, a first optical signal is reflected off the photodetector to provide a reflected beam, or the photodetector includes a reverse biased semiconductor junction including the doped semiconductor within a laser resonator including a laser medium, wherein a second optical signal is emitted. For the change in electrical conductivity the photodetector includes a reversed biased semiconductor junction that is within an electrical circuit along with an electrically driven light emitting device, where a drive current provided to the light emitting device increases as the electrical conductivity of the photodetector decreases, and the light emitting device emits a third optical signal.

Abstract: A method of forming extremely small pores in a substrate may be used to produce, for example, an apparatus for the study of biological molecules, by providing a small pore in a piezoelectric substrate having electrodes, the latter that may be energized to change the pore dimensions.

Abstract: A variable transmittance optical filter comprising: a first layer comprising a first substantially transparent substrate with a substantially co-planar (SC) electrode system disposed thereon, the SC electrode system made of transparent electrically conductive material and comprising at least one pair of electrically separate electrodes arranged in a substantially co-planar manner on the first substantially transparent substrate, each pair of electrically separate electrodes comprising a first electrode and a second electrode, a second layer proximate to the first layer and comprising a transition material that darkens in response to a non-electrical stimulus and lightens in response to application of an electric voltage; and an electrical connection system for electrically connecting the SC electrode system to a source of electric voltage.

Abstract: An electrophoresis display apparatus of this disclosure is provided with a pair of substrates, an electrophoresis layer including electrophoresis particles and a dispersion medium in which the electrophoresis particles are dispersed, a barrier wall which is arranged between the pair of substrates and divides a cell in which the electrophoresis layer is arranged, and a sealing member which seals the electrophoresis layer arranged in the cell, in which the sealing member includes a first layer and a second layer laminated on the first layer, and in which the electric resistance of the second layer is lower than that of the first layer.

Abstract: A plasmonic modulator and an optical apparatus including the same are provided. The plasmonic modulator includes a first metal layer, and a second metal layer facing the first metal layer. The plasmonic modulator further includes a refractive index varying layer disposed between the first and second metal layers and including a varying refractive index, and an insulating nitride layer disposed between the refractive index varying layer and the first metal layer.

Abstract: A nonvolatile memory storage device includes a ferroelectric (FE) material coupled with a piezoresistive (PR) material through an inherent piezoelectric response of the FE material, wherein an electrical resistance of the PR material is dependent on a compressive stress applied thereto, the compressive stress caused by a remanent strain of the FE material resulting from a polarization of the FE material, such that a polarized state of the FE material results in a first resistance value of the PR material, and a depolarized state of the FE material results in a second resistance value of the PR material.

Abstract: A display for imaging includes an aperture layer and a set of light modulators. The aperture layer includes a light absorbing layer disposed over a light reflecting layer, each layer having a set of apertures defined therein. The light absorbing layer includes light absorbing material suspended in a photosensitive resin. The set of light modulators are for modulating light passing through the apertures defined in the aperture layer.

Abstract: A display device provided with an MEMS light valve, comprising: a substrate, a fixed grating located on the substrate, an MEMS light valve for controlling the opening and closing of the fixed grating; a guide is disposed on the substrate. The MEMS light valve comprises: a movable grating, a movable electrode and fixed electrodes; the moveable grating is located in the guide and is electrically connected to the guide when contacting the guide; one end of the movable electrode is fixedly connected with the movable grating, and the other end is suspended; and the fixed electrodes and the movable electrode form a capacitor. When a potential difference forms between the fixed electrodes and the movable electrode, the movable electrode drives the movable grating to move in the guide, thereby opening and closing the fixed grating. Therefore, the MEMS light valve sensitivity can be enhanced and reliability is improved.

Abstract: Disclosed is an electrophoretic display device and manufacturing method thereof, which prevent water from penetrating into an electrophoretic film. The electrophoretic display device comprises an electrophoretic display panel comprising a substrate with a thin film transistor formed thereon, and an electrophoretic film coupled to the substrate; a protective sheet coupled to the electrophoretic film; a circuit film coupled to the substrate to be disposed at an outer side of the electrophoretic film; a first sealant formed on the substrate, for sealing a gap between the electrophoretic film and the protective sheet and a gap between the electrophoretic film and the substrate; and a second sealant sealing a gap between the substrate and the circuit film.

Abstract: A tunable metamaterial has a two dimensional array of resonant annular ring elements; and a plurality of voltage controllable electrical tuning elements disposed in or adjacent openings in each of said ring elements, each of said voltage controllable electrical tuning element ohmically contacting portions of only one of said ring elements. The voltage controllable electrical tuning elements may comprise highly doped semiconductor tunnel diodes, or the charge accumulation layer at the semiconductor/insulator interface of a metal-insulator-semiconductor structure, or nanoelectromechanical (NEMs) capacitors. The tunable metamaterial may be used, for example, in an optical beam steering device using the aforementioned tunable optical metamaterial in which a free-space optical beam is coupled into a receiving portion of a plane of the optical metamaterial and is steered out of a transmitter portion of the plane of the optical metamaterial in controllable azimuthal and elevational directions.