Abstract: Disclosed is a driving circuit for an electro-absorption optical modulator for outputting intensity-modulated signal light by receiving carrier light from a light source and absorbing the carrier light in dependence upon a driving voltage. The driving circuit includes a driving unit for applying a pulsed driving voltage to an electro-absorption optical modulator, and a variable impedance unit connected in parallel with the electro-absorption optical modulator for matching impedance with respect to the driving unit. The impedance of the variable impedance unit is switched to one value when the driving voltage is applied to the electro-absorption optical modulator and to another value when the driving voltage is not applied to the electro-absorption optical modulator so as to match impedance with respect to the driving unit.

Abstract: An electrophoretic display has a substantially two-dimensional arrangement of microcapsules each having therein an electrophoretic composition of a dielectric fluid and a suspension of particles that visually contrast with the dielectric liquid and also exhibit surface charges; a pair of electrodes, at least one of which is visually transparent, disposed on and covering opposite sides of the microcapsule arrangement; and means for creating a potential difference between the two electrodes, the potential difference causing the particles to migrate toward one of the electrodes. The display may be powered by one or more piezoelectric elements, which are also suitable for powering other types of nonemissive displays.

Abstract: An optical modulator for a high power laser transmitter includes a laser source coupled through a phase modulator to a signal modulator. A noise source provides a band limited noise signal to either the laser source or the phase modulator or both. Alternatively, an optical modulator for a high power laser transmitter includes a laser source providing a laser output optical signal and a phase modulator. First and second continuous wave signals at respective first and second frequencies are combined to modulate either the laser source or the phase modulator. The first frequency is different than the second frequency. The laser and phase modulation produces a broadened optical output signal such that the broadened optical output signal is characterized by beat frequencies harmonically related to the first and second frequencies. The modulation bandwidth includes no significant beat frequencies.

Abstract: A fiber optic spatial light modulation system which includes a light source which produces source light, an optical fiber bundle which includes a plurality of individual optical fibers, and a spatial light modulator which is interposed between the light source and the optical fiber bundle, and which selectively modulates the amount of the source light coupled into each of the individual optical fibers, wherein the amount of the source light coupled into different ones of the individual optical fibers can be unequal.

Abstract: An electrical signal to be frequency-modulated is branched into first and second signals. An FM laser 102 oscillates light having a wavelength .lambda.1 in a steady state condition, and outputs an optical signal obtained by converting an amplitude change in the inputted first signal into an optical intensity change and an optical frequency change. An optical detecting portion 106, to which the optical signal from the FM laser 102 and light having a wavelength .lambda.0 outputted from a local light source 104 are inputted, converts an optical intensity modulation component of the inputted optical signal as a current amplitude change by operating square-law detection characteristics, and generates a beat signal at a frequency corresponding to a difference in wavelength .DELTA..lambda. between the two inputted optical signals. A discrimination portion 110 discriminates using a threshold value generated on the basis of the second signal and converts the beat signal into the pulse signal.

Abstract: A single reflector, two-axis MEMS scanner made of a substrate. The substrate has nested, cut-out regions. Each region is independently rotatable about one of the axes. The axes of the regions are substantially orthogonal.

Abstract: Thin film AMA in an optical projection system and a method for manufacturing the same are disclosed. The thin film AMA has an active matrix having electrical wiring and a connecting terminal, a first actuator, a second actuator, a supporting element, and a reflecting member. The first actuator and the second actuator are parallely formed and the supporting element is formed in the direction perpendicular to the first actuator and the second actuator. The reflecting member supported by a plurality of posts is tilted by a double displacement, so the quality of a picture projected onto a screen is greatly increased. Also, the first actuator and the second actuator respectively have symmetrical structures centering around the first anchor and the second anchor so that the first actuator and the second actuator have stable structures.

Abstract: A Faraday rotator is formed of a bismuth-substituted iron garnet single crystal film on which an antireflection film is formed. The antireflection film includes first, second, and third layers. The first layer is a layer of silicon dioxide. The second layer is a layer of tantalum pentoxide. The third layer is a layer of silicon dioxide. The first, second, and third layers are formed in this order from the atmosphere side on the bismuth-substituted iron garnet single crystal film. The antireflection film may be formed on both of opposing surfaces of the single crystal film.

Abstract: An actuator having an asymmetric rigid structure for changing an optical beam path. The actuator has a base plate installed in a cover, first electrodes installed on an upper surface of the base plate by evaporation, a driving electrode disposed between the first electrodes, a pair of support plates each installed on a respective one of the first electrodes for receiving a voltage from the first electrodes, a reflecting plate disposed between the pair of support plates for reflecting an incident beam emitted from a beam source, and asymmetric members connected to the reflecting plate for adjusting an incident path of the incident beam and an inclination angle of a reflection beam with respect to the incident beam. The actuator can easily adjust the incident path of the incident beam and an inclination angle of the reflection beam with respect to the incident beam by asymmetrically inclining the reflecting plate.

Abstract: Thin film AMA in an optical projection system and a method for manufacturing the same are disclosed. The thin film AMA has a substrate having an electrical wiring for receiving a first signal applied from outside and transmitting the first signal, a first metal layer having a connecting terminal, a first passivation layer, a second metal layer, an actuator, and a reflecting member. The actuator has a supporting layer, a bottom electrode, an active layer, and a top electrode. An incident light from a light source may be excluded by means of the second metal layer formed on the first metal layer. Mis-operation of actuator due to a photo leakage current caused by an incident light can be prevented before a first signal and a second signal are respectively applied to the bottom electrode and the top electrode.

Abstract: A mechanical modulator is provided that includes a conductive substrate and at least three multilayer mirrors disposed on the substrate. The mirrors are spaced apart from one another to define upper and lower optical cavities. The upper cavity is formed by an airgap having a variable thickness. The multilayer mirror located above the airgap includes a conductive membrane having an optically transparent portion and a flexible support for orienting the membrane in a first position. Under the action of a bias, the membrane moves to a second position, changing the air gap by a fraction of a wavelength of the optical signal, as measured in air. The change in position of the membrane from the first to the second position causes a change in the total reflectivity of the modulator from a minimum to a maximum value.

Abstract: Thin film AMA in an optical projection system and a method for manufacturing the same are disclosed. The thin film AMA has a substrate having an electrical wiring and a connecting terminal, an actuator formed on the substrate, and a supporting element for supporting the actuator and for preventing an initial deflection of the actuator. The actuator has a bottom electrode, an active layer, a top electrode. The supporting element has a supporting layer attached beneath the bottom electrode for supporting the actuator, a supporting member for supporting the actuator, the supporting member being formed between the substrate where the connecting terminal is formed and a bottom of a first portion of the supporting layer, and a secondary supporting member for preventing an initial deflection of the actuator, the secondary supporting member being formed between the substrate and a bottom of a second portion of the supporting layer.

Abstract: An electrochemical display cell has a layered construction including two electrode layers separated by a dielectric layer. Concentric openings are formed in the dielectric layer and one of the electrode layers exposing a designated portion of the other electrode layer. An electrolyte layer overlaps the one electrode layer and the designated portion of the other electrode layer. When activated, current flow cascades through the openings in the one electrode layer and the dielectric layer to the designated portion of the other electrode layer supporting an electrochemical reaction that erodes the designated portion revealing underlying visual information.

Abstract: A reversible and conservative photon routing switch is implemented as a room temperature, optical, vertical cavity X-gate (also sometimes known as a Fredkin gate). Such gates are primitive structures into which all logic functions can be decomposed. The construction of the device makes it uniquely suited to dense packed arrays of optoelectronic components for optical routing and logic. In one of the switching states, light incident on the device from either side of the wafer will pass through the device (the device is bi-directionally transmissive). In the other switching state, light incident from either side of the wafer will be reflected. Switching can be performed using either electrical or optical control. Thus incident photons are either routed through the device or reflected from the device.

Abstract: A device for stabilizing a modulation operation of an optical modulator is provided, the optical modulator having an optical waveguide provided on a substrate and an electrode provided so as to correspond to the optical waveguide, modulating light inputted to the optical waveguide by a voltage corresponding to a physical amount to be measured which is inputted to the electrode, and outputting the modulated light. The device includes: an optical detecting device for outputting signal corresponding to intensity of light outputted from the optical modulator; a control signal outputting device for, on the basis of the output signal of the optical detecting device, outputting a control signal which compensates a phase bias fluctuation of the optical modulator; a light source device for outputting control light corresponding to the control signal; and a voltage applying device, provided in contact with the electrode of the optical modulator, for applying voltage corresponding to the control light to the electrode.

Abstract: A light transmittance adjusting apparatus for adjusting a windowpane of an automobile or a building has a fixed member and a movable member arranged in parallel with each other and having a plurality of light interception sections and light transmission sections formed thereon alternately. The vertical position of the movable member are changed electrostatically relative to the fixed member to adjust the light transmittance of the windowpane. Each light interception section has a semi-interception region, the light transmittance of which decreases gradually from a center region thereof toward the adjacent light transmission section. The semi-interception region of the light interception section of a light interception plate of the fixed member overlap the semi-interception region of the light interception section of a light interception plate of the movable member, thus accomplishing an optical interception completely.

Abstract: An electrostatic memory micromirror display system including an array of electrostatic memory and display assemblies each including a memory and display element having a mirror surface and a conductive medium; a support device for movably mounting the memory and display element; and a set of electrodes including at least first and second electrodes proximate the conductive medium; and means for selectively applying a voltage to the first electrode of predetermined ones of the memory and display assemblies to establish an electrostatic field between the first electrode and the conductive medium to urge the associated display element from a first position toward a second position and for applying a voltage to the second electrode of the assemblies to establish an electric field between the second electrode and the conductive medium to set the memory and display element in the second position.

Abstract: A virtual image display system includes a reflective mode spatial light modulator, a light source for illuminating the spatial light modulator, and an optics arrangement for directing a predetermined portion of the light from the light source into the spatial light modulator and for directing certain portions of the light reflected from the spatial light modulator to a desired viewing area. The optics arrangement includes an overall polarizing beam splitter. The polarizing beam splitter has three layers of materials. The first layer is a layer of polarizing beam splitting material configured to reflect light of a first polarization and transmit light of a second polarization. The second layer is another layer of polarizing beam splitting material. The third layer is a layer of material positioned between the first and second layers of polarizing beam splitting materials. The first, second, and third layers of materials act together to form the overall polarizing beam splitter.

Abstract: A traveling-wave electro-optic modulator using reflected signals to achieve a one-time rephasing. For a given crystal length, the interaction length is effectively doubled and a 3-dB gain is automatically achieved compared to a conventional traveling-wave modulator.

Abstract: An optical assembly comprising an optical element and a transducer is suspended within an enclosure so that the optical assembly is free to vibrate within the enclosure. In one embodiment, the mechanisms for suspending the assembly do away with any elastomeric material that would cause outgassing in applications where the photoelastic modulator is used in a high vacuum environment. The suspension system also increases the efficiency of the system.