Patents Assigned to Acreo AB
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Patent number: 6973247Abstract: The invention relates to a method and a device for controlling the refractive index in the core of an optical fiber. According to the invention, an optical fiber is provided with a longitudinal electrode running along the core of the fiber. An electric current is passed through the electrode to induce ohmic heating thereof, causing thermal expansion and consequently a compressing force upon the core of the fiber. This compression of the core leads to induced changes in the refractive index in the direction of the compressing force, and hence induces or alters birefringence in the core.Type: GrantFiled: July 2, 2002Date of Patent: December 6, 2005Assignee: Acreo ABInventors: Michael Fokine, Lars-Erik Nilsson, Åsa Claesson, Walter Margulis, Leif Kjellberg, Hania Arsalane, Pedro Torres
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Patent number: 6806511Abstract: An electrochemical transistor device is provided, comprising a source contact, a drain contact, at least one gate electrode, an electrochemically active element arranged between, and in direct electrical contact with, the source and drain contacts, which electrochemically active element comprises a transistor channel and is of a material comprising an organic material having the ability of electrochemically altering its conductivity through change of redox state thereof, and a solidified electrolyte in direct electrical contact with the electrochemically active element and said at least one gate electrode and interposed between them in such a way that electron flow between the electrochemically active element and said gate electrode(s) is prevented. In the device, flow of electrons between source contact and drain contact is controllable by means of a voltage applied to said gate electrode(s).Type: GrantFiled: March 7, 2002Date of Patent: October 19, 2004Assignee: Acreo ABInventors: Mårten Armgarth, Miaoxiang Chen, David A. Nilsson, Rolf M. Berggren, Thomas Kugler, Tommi Remonen
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Patent number: 6670705Abstract: A semiconductor device comprises at least one first semiconductor layer (1-4) and a second layer (8) applied on at least a surface portion of the first layer for protecting the device. The protecting layer is of a second material having a larger energy gap between the valence band and the conduction band than a first material forming said first layer. The second material has at least in one portion of said protecting layer a nano-crystalline and amorphous structure by being composed of crystalline gains with a size less than 100 nm and a resistivity at room temperature exceeding 1×1010 &OHgr;cm.Type: GrantFiled: June 25, 2002Date of Patent: December 30, 2003Assignee: Acreo ABInventors: Christopher Harris, Mietek Bakowski, Jan Szmidt
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Patent number: 6642069Abstract: A pixel device comprising an electrochemical transistor device with a source and a drain contact; a gate electrode; an electrochemically active element in direct electrical contact with source and drain contacts, and comprising a transistor channel comprising an organic material; and a solidified electrolyte in direct electrical contact with the active element, and an electrochromic device comprising an electrochromic element comprising a material conducting in at least one oxidation state and an electrochromic material; a solidified electrolyte layer in direct electrical contact with the electrochromic element; and two electrodes for application of a voltage and in direct electrical contact with a component selected from the electrolyte layer(s); in which one of the source and drain contacts of the electrochemical transistor device is in electrical contact with one of the electrodes of the electrochromic device.Type: GrantFiled: March 7, 2002Date of Patent: November 4, 2003Assignee: Acreo ABInventors: Mårten Armgarth, Karl P. Andersson, David A. Nilsson, Rolf M. Berggren, Thomas Kugler, Tommi Remonen
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Patent number: 6587250Abstract: A supported or self-supporting electrochromic device is provided having (a) at least one electrochromic element comprising (i) at least one material that is electrically conducting in at least one material that is electrically conducting in at least one oxidation state and (ii) at least one electrochromic material, wherein said materials (i) and (ii) can be the same or different, (b) at least one layer of a solidified electrolyte which is in direct electrical contact with said electrochromic element, and (c) at least two electrodes adapted to be electrically connected to a voltage supply so as to create a difference in potential therebetween, with each of said electrodes being in direct electrical contact with at least one of said electrolyte layer(s) and not in direct electrical contact with said electrochromic element. Displays incorporating such a device, as well as processes for the production of such a device are contemplated. A method for addressing an electrochemically active element also is provided.Type: GrantFiled: March 7, 2002Date of Patent: July 1, 2003Assignee: Acreo ABInventors: Mårten Armgarth, Thomas Kugler, Rolf M. Berggren, Tommi M. Remonen
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Patent number: 6512873Abstract: In an optical fiber or other light guiding body is utilized that the diffusion properties of fluorine, which reduces the refractive index, are strongly changed, if also a doping with phosphorous is made, to change the refractive index and hereby the light guiding properties. In for example a single mode fiber (1) thus locally an additional waveguide core (9) can be created parallel to the already existing waveguide core (3), by providing in parallel to the ordinary core (3) an activatable region (5) having substantially the sane dimensions as the existing core and having suitable dopings of fluorine and phosphorous. This can be utilized to produce an optical filter element If the optical fiber is D-fiber, a sensor element can be produced. Furthermore, for suitable concentrations of these dopants and of germanium an existing waveguide core can be erased by a heating operation.Type: GrantFiled: January 31, 2001Date of Patent: January 28, 2003Assignee: Acreo ABInventor: Michael Fokine
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Patent number: 6278133Abstract: A field effect transistor of SiC for high temperature application has the source region layer (4), the drain region layer (5) and the channel region layer (6, 7) vertically separated from a front surface (14), where a gate electrode (12) is arranged, for reducing the electric field at said surface in operation of the transistor and in the case of operation as a gas sensor permitting all electrodes except for the gate electrode to be protected from the atmosphere.Type: GrantFiled: April 23, 1999Date of Patent: August 21, 2001Assignee: Acreo ABInventors: Christopher Harris, Andrei Konstantinov, Susan Savage
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Patent number: 6252250Abstract: In a high power IMPATT ( Impact Avalanche Transit Time) diode for generating high frequency signals two electrodes, anode (2) and cathode (1), are arranged with a semiconductor layer therebetween. Said semiconductor layer comprises a drift layer (7) for transport of charge carriers between the electrodes. The semiconductor layer is made of crystalline SiC and it is provided with means (9) adapted to locally increase the electric field in the drift layer substantially with respect to the average electric field therein for generating an avalanche breakdown at a considerably lower voltage across the electrodes than would the electric field be substantially constant across the entire drift layer.Type: GrantFiled: March 19, 1999Date of Patent: June 26, 2001Assignee: Acreo ABInventors: Christopher Harris, Andrei Konstantinov
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Patent number: 6127695Abstract: A lateral field effect transistor of SiC for high switching frequencies comprises a source region layer (5) and a drain region layer (6) laterally spaced and highly doped n-type, an n-type channel layer (4) extending laterally and interconnecting the source region layer and the drain region layer for conducting a current between these layers in the on-state of the transistor, and a gate electrode (9) arranged to control the channel layer to be conducting or blocking through varying the potential applied to the gate electrode. A highly doped p-type base layer (12) is arranged next to the channel layer at least partially overlapping the gate electrode and being at a lateral distance to the drain region layer. The base layer is shorted to the source region layer.Type: GrantFiled: February 8, 1999Date of Patent: October 3, 2000Assignee: Acreo ABInventors: Christopher Harris, Andrei Konstantinov