Abstract: An optical device which can be used as a Faraday rotator which can provide an arbitrary Faraday rotation angle in accordance with a positional condition. The optical device includes first and second ports, magneto-optical crystal, and a unit for applying a magnetic field to the magneto-optical crystal. The first port is positioned in a first region while the second port is positioned in a second region. The first and second ports are optically coupled by a light beam. The magneto-optical crystal is provided such that the light beam may pass therethrough. The unit for applying applies a magnetic field to the magneto-optical crystal so that magnetization of the magneto-optical crystal may have a given distribution in a plane substantially perpendicular to the light beam.

Abstract: A method for introducing desired electromagnetic radiation into a photonic crystal having a photonic bandgap and at least one defect, wherein the desired electromagnetic radiation has a frequency within the photonic bandgap. The method includes the steps of: delivering source electromagnetic radiation having an electromagnetic frequency outside the photonic bandgap to the defect; and generating the desired electromagnetic radiation at the defect in response to the source electromagnetic radiation.

Abstract: A wideband semiconductor electro-absorption optical modulator including a semiconductor core shorter in absorption-peak wavelength than a wavelength of optical signal, and an electrode for applying an electric signal to absorb the optical signal by shifting the absorption-peak wavelength to a long wavelength region when a voltage is applied, wherein an electric signal input port and an electric signal output port are disposed so that the electrode is constructed in the form of a traveling-wave electrode, and a total thickness of non-doped layers including the semiconductor core is reduced to decrease a driving voltage. Degradation of optical modulation bandwidth and reflection characteristics of the electric signal caused by mismatching of characteristic impedance to an outer circuit are reduced by decreasing an interaction length of the electric signal and the optical signal.

Abstract: An optical modulator suitable for use in, for example, a terminal apparatus in an optical communication system when an optical signal is modulated has a power splitting unit for splitting a power of an incident light into two split lights, a first intensity modulating unit for performing an intensity modulation on one of the split lights split by the power splitting unit and outputting an intensity-modulated optical signal containing a direct current component, an optical phase shifting unit for performing a phase shift on the other of the split lights split by the power splitting unit such that the light has a phase opposite to that of the intensity-modulated optical signal, and a direct current component suppressing unit for making the intensity-modulated optical signal and the light subjected to the phase shift interfere with each other to suppress the direct current component contained in the intensity-modulated optical signal and outputting the intensity-modulated optical signal, thereby obtaining the mo

Abstract: An electrochromic device is provided having an electrochromic conducting polymer layer in contact with a flexible outer layer. A conductive reflective layer is disposed between the electrochromic conducting polymer and a substrate layer. A liquid or solid electrolyte contacts the conductive reflective layer and a counter electrode in the device. A liquid electrolyte may comprise, for example, a mixture of sulfuric acid, poly(vinyl sulfate), and poly(anethosulfonate). A solid electrolyte may comprise, for example, a mixture of sulfuric acid, poly(vinyl sulfate), poly(anethosulfonate), and poly(vinyl alcohol).

Abstract: A method of making a light modulator (10) for modulating an incident beam of light includes a substrate (14) having a cavity (32)formed therein and a plurality of spaced-apart deformable elements (12) formed in the cavity (32). The deformable elements (12) each has a base layer (16), a poled magnetic layer (18) formed in the base layer (16) and a first light reflection layer (20)deposited on the magnetic layer (18) for reflecting an incident beam of light. Between adjacent deformable elements on the base (12) of the cavity (32) is arranged a second light reflection layer (36). A conductive element (22, 24) formed in the substrate (14) electro-magnetically energizes the deformable elements (12) to deflect in the cavity (32). Incident light passing through each one of the first light reflection layers (20) is caused to destructively interfere with light reflected from the second light reflection layers (36) thereby causing modulation of the incident light.

Abstract: An electrostatically actuated micromirror light modulator that exhibits increased deflection range, better charge efficiency and improved electrostatic stability. A thin insulating membrane decouples the electron beam from the micromirror array inside the vacuum cell. The membrane is just thick enough to stop the incident electrons from penetrating through to the mirrors but is thin enough to maintain resolution of the deposited charge pattern. An equipotential layer beneath the mirror array prevents any attractive force from being developed due to the accumulation of static charge on the surface of the light modulator that may otherwise cause the mirror to snap-over and become stuck to the substrate.

Abstract: Light in the visible spectrum is modulated using an array of modulation elements, and control circuitry connected to the array for controlling each of the modulation elements independently, each of the modulation elements having a surface which is caused to exhibit a predetermined impedance characteristic to particular frequencies of light. The amplitude of light delivered by each of the modulation elements is controlled independently by pulse code modulation. Each modulation element has a deformable portion held under tensile stress, and the control circuitry controls the deformation of the deformable portion. Each deformable element has a deformation mechanism and an optical portion, the deformation mechanism and the optical portion independently imparting to the element respectively a controlled deformation characteristic and a controlled modulation characteristic. The deformable modulation element may be a non-metal.

Abstract: A spatial light modulator for use in a optical printer where the spatial light modulator includes a plurality of cells, having a shape that is defined to decrease artifacts in an image produced on a recording medium by the optical printer. The shape of the plurality of cells merges a portion of the optical radiation passing through an individual cell of the spatial light modulator with optical radiation from that of adjacent cell to form a pixel on the recording medium. In one implementation each of the cells of the spatial light modulator independently modulate the optical radiation so as to print horizontally-displaced pixels. When LEDs are used as the colored light source, the light is either first diffused to minimize shadows from electrical contacts on the LEDs, thus removing linear artifacts in the image.

Abstract: A projection display system includes a thin film polarizing beam splitter/combiner has first and second light transmissive substrates in the form of prisms and a plurality of thin film layers disposed between the prisms. The thin film layers and have predetermined thicknesses and refractive indices which allow unpolarized incident light to be separated into s-polarized and p-polarized light beams. Both frustrated total internal reflection and thin film interference are simultaneously employed to allow s-polarized light to be transmitted and p-polarized light to be reflected over a wide range of wavelengths and angles of incidence. The device further includes two spatial light modulators for encoding an image to be projected. By providing a different signal to each spatial light modulator, a three-dimensional display results.

Abstract: An apparatus for controlling a charge state of an electrochromic devices according to the invention, where the electrochromic devices receives a charging current, comprises: a reference impedance, coupled to receive a reference current proportional to the charging current, the reference impedance having a known impedance relationship with the electrochromic device; a comparator, coupled to the reference impedance, for comparing a voltage level of the reference impedance to a threshold voltage level and producing an output signal indicative of the comparison; and control logic, coupled to the comparator, for simultaneously adapting the reference current and the charging current in response to the output signal of the comparator. In one embodiment of the invention, the apparatus is included within a pair of eyeglasses.

Abstract: A deformable mirror device for changing a proceeding path of an incident light includes a substrate, a pair of posts protruding from the upper surface of the substrate and spaced a predetermined distance from each other, an electrode formed on the upper surface of the substrate, a reflection mirror arranged to face the electrode by being supported by the posts, and first and second support pieces having predetermined rigidities for supporting the reflection mirror. The support pieces are connected between the reflection mirror and the posts so that an inclination of the reflection mirror can be adjusted by an electrostatic attraction between the electrode and the reflection mirror. The electrode is arranged to be offset from the reflection mirror such that a magnitude of the forces applied to the electrode at the positions between each of the first and second support pieces and the reflection mirror differ from each other.

Abstract: An optical homogenizer is disclosed which enables an optical system to obtain the benefits of a high quantum efficiency photon detector without suffering from its non-uniform response. The optical homogenizer has an input end for receiving light emitted from a light source and an output end that produces a relatively uniform distribution of light along a spatial dimension of the photon detector in response to the light source. The optical homogenizer ensures that the photon detector is uniformly illuminated from the output end regardless of where photons from the light source enter the input end.

Abstract: A method for mechanically stabilizing and for tuning a filter having a photonic crystal structureThe cavities of the filter fabricated as a photonic crystal structure are filled with optically transparent material having an adjustable refractive index. The optical properties of the filter and, thus, the filtering action are adjusted by way of an electric field having a variable field strength.It is possible to produce small-dimensioned, narrow-band filter elements, which are finely tunable and tunable within a broad range, and to realize them as filter elements which are integrated with a high packaging density.

Abstract: A method and concomitant apparatus for use in an electrochromic control system in which components causing the charging and discharging of an electrochromic device are subject to drift errors and other errors. In the case of such errors, the actual programming level and the desired programming level as indicated by, e.g., a count value, may diverge. The invention periodically determines the actual programming level of the electrochromic device and responsively adjusts a parameter representative of the desired programming level.

Abstract: A polarization independent optical phase modulator comprises first and second substrates. A reflector is disposed between the first and second substrates and a quarterwave plate is disposed between the reflector and the first substrate. A polarization dependent electrooptic layer is disposed between the quarterwave plate and the first substrate. The quarterwave plate has an optic axis which is aligned at 45 degrees to the polarization whose phase is modulated by the electrooptic layer.

Abstract: The invention comprises an apparatus and methodology facilitating an accurate, user-friendly system for controlling the charge state (i.e., color level) of an electrochromic device. The invention provides a two button control methodology implemented as a sequential logic controller or, in another embodiment, a microprocessor-based controller. After initiation via, e.g., an external switch, the invention iteratively modifies and measures a charge level of the electrochromic device until an additional switch activation or until a maximal or minimal charge level is achieved.

Abstract: In a non-collinear type acousto-optic tunable filter, the incident angle of a source light beam L.sub.1 radiated from a light source 6 onto an acoustic medium 1 is set at an equivalence incident angle for which the wavelength .lambda..sub.i of the diffracted ordinary ray L.sub.3 and the wavelength .lambda..sub.i ' of the diffracted extraordinary ray L.sub.4 become approximately identical. Further, the diffracted ordinary ray L.sub.3 and the diffracted extraordinary ray L.sub.4 of the approximately identical wavelength are superposed, and the intensity of the superposed ray is detected. Consequently, spectrometry is performed based on the superposed diffracted ray having twice the intensity and a very sharp waveform, so that accurate spectroscopy can be made possible even if the intensity of the source light beam is low.

Abstract: A method for sealing the circumferential edge region of a laminated electrochromic device is disclosed. The method involves cutting a circumferential groove into the edge region of the device at the ion-conducting interface of its substrates. Sealant is then applied to the groove. Sealed devices are also disclosed.

Abstract: An optical modulator that contains a flexible dielectric membrane suspended over a substrate. The flexible membrane is made of a dielectric material such as silicon nitride. In one embodiment of the invention, the flexible membrane has an optically active region. A contact region is maintained in the vicinity of the optically active region which is electrically isolated therefrom. The contact region which includes a conductive material draws accumulated charge build-up from the optically active region. In another embodiment a first area of conductive material is formed on at least one surface of the flexible membrane proximate its center. At least one second area of conductive material is formed on at least one surface of the flexible membrane surrounding the first area. The first area of conductive material is kept electrically isolated from the surrounding second area. The first area of conductive material is coupled to an electrical ground.