Abstract:
Various exemplary embodiments relate to an optical isolator in an integrated optical circuit including: a first optical modulator configured to provide a first periodic phase modulation on an input optical signal; a second optical modulator configured to provide a second periodic phase modulation on the modulated optical signal; and an optical waveguide having a length L connecting the first optical modulator to the second optical modulator; wherein the phase difference between the first and second periodic phase modulation is π/2, and wherein the length L of the optical waveguide causes a phase delay of π/2 on an optical signal traversing the optical waveguide.
Abstract:
An optical device for generating a frequency comb includes an optical source and a first waveguide comprising a nonlinear optical medium operable to mix at least two input optical waves to generate a plurality of first optical waves. The optical device also includes a second waveguide concatenated to the first waveguide and characterized by a first dispersion characteristics and operable to compress the waveforms of the plurality of first optical waves and to reduce a frequency chirp introduced by the first waveguide. The optical device additionally includes a third waveguide concatenated to the second waveguide. The third waveguide comprises a nonlinear optical medium and is operable to mix the plurality of first optical waves to generate a plurality of second optical waves and to increase a total number of second optical waves with respect to a total number of first optical waves.
Abstract:
An electrochromic device (ECD) includes an electrochromic cell and, optionally, one or more additional electrochromic cells where all cells are parallel, and where at least one of the electrodes of one of the cells comprises a single-walled carbon nanotube (SWNT) film The electrochromic cells allow the control of transmittance of two or more different portions of the electro-magnetic spectrum through the ECD. One cell can control the transmittance of visible radiation while the other cell can control the transmittance of IR radiation. The ECD can be employed as a “smart window” to control the heat and light transmission through the window. The ECD can be in the form of a laminate that can be added to an existing window.
Abstract:
A disclosed electrochromic display element includes a display substrate, a counter substrate facing the display substrate, display electrodes arranged between the display substrate and the counter substrate, electrochromic layers formed on the respective display electrodes, a plurality of drive elements arranged on the counter substrate at predetermined intervals, a plurality of pixel electrodes arranged on the drive elements, a charge retention layer formed over the pixel electrodes as a continuous layer, the charge retention layer being formed of a mixed film including a polymer and one of electric conductive microparticles and semiconductor microparticles, and an electrolyte layer sandwitched between the display substrate and the charge retention layer.
Abstract:
In an optical modulator, respective lights for where one input light has been branched, are input via a curved waveguide to a plurality of optical modulation sections arranged in parallel on the same substrate. In a Mach-Zehnder type optical waveguide, a spacing between the pair of branching waveguides of the adjacent optical modulation sections, is formed so as to become wider in the vicinity of a border of an input side polarization inversion region than in the vicinity of a start point of an interaction portion. As a result, even if a signal electrode of the optical modulation sections shifts at the boundary portion of the polarization inversion region, the spacing between the signal electrodes does not become narrow, and hence the radius of curvature of curved waveguides for guiding the input light to the respective optical modulation sections can be increased, so that it becomes possible to apply input light to the optical modulation sections at low loss.
Abstract:
The invention discloses a device for selecting pulses comprising an optical waveguide for guiding the optical radiation along an axis; comprising a first electro-optical modulator designed to modulate the optical transparency of the waveguide; comprising a second electro-optical modulator designed to modulate the optical transparency of the waveguide, wherein the first modulator and the second modulator are arranged one after the other on the axis of the waveguide, and further comprising at least one control circuit designed to actuate the first modulator and the second modulator at offset times, and characterized in that a substrate of a semiconductive material is provided, the waveguide and the at least one control circuit are arranged on the substrate.
Abstract:
There is described an optical modulation system for transmitting modulated optical light. The system comprises an electro-optic modulator having at least two arms through which light is transmitted and an imbalance electrode located on at least one arm. A current source is configured to inject current into the imbalance electrode for modifying the phase of light passing through the arm. A dither generator is configured to modulate the injected current, or bias voltage applied to at least one of the arms, with a dither signal. A phase sensitive detector is configured to detect an error in the phase of light emitted by the modulator. An operating point controller is configured to monitor the detected phase error and adjust the current injected into the imbalance arm so as to compensate for the detected error and thereby control an operating point of the modulator.
Abstract:
A voltage-tuned optical filter that is low cost and simple to fabricate uses cascaded etalon modules, each module comprising a liquid crystal etalon, such as a Fabry-Perot etalon, having a relatively small Free Spectral Range (FSR). At least two of the modules are provided with a voltage control to enable Vernier tuning control. For a given overall scan, the voltage-tuned optical filter may operate with reduced voltage ranges for each liquid crystal etalon.
Abstract:
Methods, systems and apparatus for manipulating electromagnetic radiation such as laser beams. A method and apparatus for correcting magnification chromatic aberration utilizes one or more dispersive lenses such that long wavelength components are magnified less than short wavelength components. A telecentric relay is preferred to achieve this aim. Further, the use of polarizers to block the undesired zeroth order components of diffraction emanating from acousto-optic deflectors (AODs) is disclosed. Furthermore, specific designs of AOD including narrow transducer AODs which produce a diverging acoustic wave and AODs having two transducers and a selection switch are disclosed. Further, the invention provides methods, systems and apparatus for allowing the wavelength of radiation to be changed, for providing a user selectable degree of compensation, for providing a scanning and/or a pointing system and for providing a compact system that does not require telecentric relays between adjacent acousto-optic deflectors.
Abstract:
Electrochemical/electrically controllable device having variable optical and/or energetic properties, including a first carrier substrate provided with an electrically conductive layer associated with a first stack of electrically active layers and a second carrier substrate provided with an electrically conductive layer associated with a second stack of electrically active layers, wherein the first and second stacks each function optically in series on at least a portion of their surface and are separated by an electrically insulating means, which is a gas, or is a vacuum.