Patents by Inventor Udo W. Pohl

Udo W. Pohl has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8502197
    Abstract: A device including a locally modified buried first layer. A second layer is arranged on top of the first layer. The first layer includes at least one modified section and at least one unmodified section. The modified material of the locally modified buried first layer changes or induces mechanical strain in a portion of the second layer which is arranged above the at least one modified section. At least one nanostructure is placed on top of the second layer in an area, which is located above the at least one unmodified section of the first layer or adjacent thereto, said at least one nanostructure being formed by a strain-sensitive third material deposited on the locally strained second layer.
    Type: Grant
    Filed: December 11, 2012
    Date of Patent: August 6, 2013
    Assignee: Technische Universitat Berlin
    Inventors: André Strittmatter, Andrei Schliwa, Tim David Germann, Udo W. Pohl, Vladimir Gaysler, Jan-Hindrik Schulze
  • Patent number: 8349712
    Abstract: The invention inter alia relates to a method of fabricating a layer assembly comprising the steps of: arranging a first layer on top of a carrier; arranging a second layer on top of the first layer; locally modifying the material of the buried first layer and providing at least one modified section in the first layer, wherein the modified material changes or induces mechanical strain in a portion of the second layer which is arranged above the at least one modified section; after locally modifying the material of the buried first layer, depositing a third material on top of the second layer, at least one characteristic of the third material being sensitive to the local mechanical strain in the second layer.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: January 8, 2013
    Assignee: Technische Universitat Berlin
    Inventors: André Strittmatter, Andrei Schliwa, Tim David Germann, Udo W. Pohl, Vladimir Gaysler, Jan-Hindrik Schulze
  • Publication number: 20120248403
    Abstract: The invention inter alia relates to a method of fabricating a layer assembly comprising the steps of: arranging a first layer on top of a carrier; arranging a second layer on top of the first layer; locally modifying the material of the buried first layer and providing at least one modified section in the first layer, wherein the modified material changes or induces mechanical strain in a portion of the second layer which is arranged above the at least one modified section; after locally modifying the material of the buried first layer, depositing a third material on top of the second layer, at least one characteristic of the third material being sensitive to the local mechanical strain in the second layer.
    Type: Application
    Filed: March 30, 2011
    Publication date: October 4, 2012
    Inventors: André STRITTMATTER, Andrei Schliwa, Tim David Germann, Udo W. Pohl, Vladimir Gaysler, Jan-Hindrik Schulze
  • Publication number: 20110263108
    Abstract: The invention relates to a method of fabricating at least one semiconductor quantum dot at a predefined position, comprising the steps of: patterning a semiconductor base material using nanoimprint lithography and an etching step, to form at least one nano-hole at the predefined position in the semiconductor base material; and growing the at least one semiconductor quantum dot in or on top of the at least one nano-hole by metalorganic chemical vapor deposition.
    Type: Application
    Filed: April 27, 2010
    Publication date: October 27, 2011
    Inventors: Hongbo Lan, Udo W. Pohl, Dieter Bimberg
  • Patent number: 6893950
    Abstract: A process for the production of contacts for electrically operated II/VI semiconductor structures (for example laser diodes). The contact materials palladium and gold hitherto used in relation to electrically operated II/VI semiconductor lasers are distinguished by a relatively great, not purely ohmic specific contact resistance in relation to the II/VI cover layer. The consequentially necessary higher operating voltages result in the unnecessary generation of heat and thus substantially accelerate degradation of the entire laser structure. That effect causes a limitation in terms of the service life of II/VI semiconductor laser diodes. The invention permits the operation of semiconductor laser diodes with lower operating voltages. The II/VI semiconductor laser diodes produced with our invention are distinguished by a longer service life. That permits inter alia commercial use of semiconductor laser diodes in the blue-green spectral range.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: May 17, 2005
    Assignee: Technische Universitaet Berlin
    Inventors: Matthias Strassburg, Oliver Schulz, Udo W. Pohl, Dieter Bimberg
  • Publication number: 20040219697
    Abstract: A process for the production of contacts for electrically operated II/VI semiconductor structures (for example laser diodes). The contact materials palladium and gold hitherto used in relation to electrically operated II/VI semiconductor lasers are distinguished by a relatively great, not purely ohmic specific contact resistance in relation to the II/VI cover layer. The consequentially necessary higher operating voltages result in the unnecessary generation of heat and thus substantially accelerate degradation of the entire laser structure. That effect causes a limitation in terms of the service life of II/VI semiconductor laser diodes. The invention permits the operation of semiconductor laser diodes with lower operating voltages. The II/VI semiconductor laser diodes produced with our invention are distinguished by a longer service life. That permits inter alia commercial use of semiconductor laser diodes in the blue-green spectral range.
    Type: Application
    Filed: November 24, 2003
    Publication date: November 4, 2004
    Applicant: Technische Universitaet Berlin
    Inventors: Matthias Strassburg, Oliver Schulz, Udo W. Pohl, Dieter Bimberg
  • Patent number: 6673641
    Abstract: A process for the production of contacts for electrically operated II/VI semiconductor structures (for example laser diodes). The contact materials palladium and gold hitherto used in relation to electrically operated II/VI semiconductor lasers are distinguished by a relatively great, not purely ohmic specific contact resistance in relation to the II/VI cover layer. The consequentially necessary higher operating voltages result in the unnecessary generation of heat and thus substantially accelerate degradation of the entire laser structure. That effect causes a limitation in terms of the service life of II/VI semiconductor laser diodes. The invention permits the operation of semiconductor laser diodes with lower operating voltages. The II/VI semiconductor laser diodes produced with our invention are distinguished by a longer service life. That permits inter alia commercial use of semiconductor laser diodes in the blue-green spectral range.
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: January 6, 2004
    Assignee: Technische Universitaet Berlin
    Inventors: Matthias Strassburg, Oliver Schulz, Udo W. Pohl, Dieter Bimberg