Patents by Inventor Pak Cho

Pak Cho 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).

  • Publication number: 20070274733
    Abstract: An optical device is provided with first and second inputs. A first coupler coupled is coupled to the first input and produces at least a first and second output. A second coupler is coupled to the second input and produces at least a first and second output. A third coupler is coupled to the first output of the first coupler and to the first output of the second coupler. A fourth coupler is coupled to the second output of the first coupler and to the second output of the second coupler. First and second crossing waveguides are provided with an angle selected to minimize crosstalk and losses between the first and second cross waveguides. The first crossing waveguide connects one of the first or second outputs from the first coupler with an input of the fourth coupler. The second crossing waveguide connects one of the first or second outputs from the second coupler with an input of the third coupler. A first phase shifter is coupled to the first and second waveguides.
    Type: Application
    Filed: April 3, 2007
    Publication date: November 29, 2007
    Inventors: Isaac Shpantzer, Aviv Salamon, Pak Cho
  • Publication number: 20070140613
    Abstract: The present invention provides an integrated device and a method of its fabrication and use. Two parts of the device each having an electronic circuit are aligned adjacent to each other with an accuracy of at least 1 micron. An alignment system includes two parts: a first part integrated with the first electronic circuit of the integrated device on the first substrate and a second part integrated with the second electronic circuit of the integrated device on the second substrate. The second part of alignment system includes at least one photodiode. The maximal value of the photodiode current indicates the best alignment of two parts of the integrated device. In one embodiment the integrated device is a coherent optical detector for high speed optical communications and chemical sensing. In another embodiment the integrated optical device is a coherent optical detector operating in two polarization states of light.
    Type: Application
    Filed: February 7, 2007
    Publication date: June 21, 2007
    Inventors: Yaakov Achiam, Isaac Shpantzer, Arthur Greenblatt, Geoffrey Harston, Arkady Kaplan, Pak Cho
  • Publication number: 20070140705
    Abstract: One embodiment of the invention relates to producing optical pulses for use on a transmission link. A light source is configured to produce an optical signal. A pulse generator is coupled to the light source. The pulse generator is configured to receive, for a first channel, the optical signal and a clock signal. The pulse generator is also configured to modify the optical signal based on the clock signal to produce an optical pulse having a predetermined pulse shape. The clock signal is associated with the predetermined pulse shape.
    Type: Application
    Filed: December 27, 2006
    Publication date: June 21, 2007
    Inventors: Isaac Shpantzer, Israel Smilanski, Jacob Khurgin, Vladimir Grigoryan, Pak Cho, Nadejda Reingand, Guy Levy-Yurista, Guoliang Li
  • Publication number: 20070110362
    Abstract: An optical device is provided with first and second inputs. A first coupler coupled is coupled to the first input and produces at least a first and second output. A second coupler is coupled to the second input and produces at least a first and second output. A third coupler is coupled to the first output of the first coupler and to the first output of the second coupler. A fourth coupler is coupled to the second output of the first coupler and to the second output of the second coupler. First and second crossing waveguides are provided with an angle selected to minimize crosstalk and losses between the first and second cross waveguides. The first crossing waveguide connects one of the first or second outputs from the first coupler with an input of the fourth coupler. The second crossing waveguide connects one of the first or second outputs from the second coupler with an input of the third coupler. A first phase shifter is coupled to the first and second waveguides.
    Type: Application
    Filed: December 14, 2006
    Publication date: May 17, 2007
    Inventors: Isaac Shpantzer, Arkady Kaplan, Aviv Salamon, Yaakov Achiam, Jacob Khurgin, Michael Tseytin, Pak Cho, Arthur Greenblatt, Christopher Kerr, Geothrey Harston
  • Publication number: 20050185191
    Abstract: An optical system provides information about tangential vibration components of a surface at remote location. The optical system includes a light source assembly that emits first and second beams, each having one or more wavelengths and one or two polarizations. The first and second beams are directed to the interrogated surface. A detector system is positioned to detect a third beam formed by at least a portion of the first and second beams being reflected from the interrogated surface. The first, second and third beams having incident and reflection angles relative to the interrogated surface that do not lay in a same plane. The detector system positioned remotely from the interrogated surface, and providing information on a phase change in the third beam relative to the first and second beam. The phase change is indicative of at least one surface vibration vector component of the interrogated surface. The detector system is a 90 degree optical hybrid balanced detector with four photodiodes.
    Type: Application
    Filed: February 9, 2005
    Publication date: August 25, 2005
    Inventors: Isaac Shpantzer, Aviv Salamon, Pak Cho
  • Publication number: 20050105099
    Abstract: A photo-thermal, interferometric spectroscopy system is disclosed that provides information about a chemical at a remote location. A first light source assembly is included that emits a first beam. The first beam has one or more wavelengths that interact with the chemical and change a refractive index of the chemical. A second laser produces a second beam. The second beam interacts with the chemical resulting in a third beam with a phase change that corresponds with the change of the refractive index of the chemical. A detector system is positioned remote from the chemical to receive at least a portion of the third beam. The detector system provides information on a phase change in the third beam relative to the second beam that is indicative of at least one of, absorption spectrum and concentration of the chemical.
    Type: Application
    Filed: January 13, 2005
    Publication date: May 19, 2005
    Inventors: Isaac Shpantzer, Jacob Khurgin, Pak Cho, Yaakov Achiam