Patents by Inventor John D. Bierlein

John D. Bierlein 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: 5393561
    Abstract: Segmented waveguides for wavelength conversion (e.g., waveguides comprising alternating sections of crystalline substrate having the formula K.sub.1-x Rb.sub.x TiOMO.sub.4 where x is from 0 to 1 and M is P or As and sections of substrate material in which cations of said substrate have been partially replaced) and devices and processes employing segmented waveguides for wavelength conversion are disclosed wherein a periodic structure along the waveguide provides a Bragg reflection having a wavelength essentially equal to the wavelength of the input wave used for wavelength conversion. Also disclosed is a process for preparing a channel waveguide for a wavelength conversion system wherein areas along a portion of a crystal substrate surface used for forming the desired channel are alternately masked and unmasked during cation replacement by immersion in a molten salt.
    Type: Grant
    Filed: March 24, 1993
    Date of Patent: February 28, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, William Bindloss, Fredrik Laurell, Jerald D. Lee
  • Patent number: 5311352
    Abstract: Method and device for wavelength conversion using type II phase matching are characterized by employing a crystal consisting essentially of doped MTiOXO.sub.4 (wherein M is K, Rb and/or Tl and X is P and/or As) containing Fe, Nb and/or Ta dopant in an amount, totalling at least about 100 ppm, effective to increase the n.sub.z -n.sub.x optical birefringence of the doped crystal at least about 0.001 compared to a crystal without the dopant. Generation of output waves of an optical birefringence higher than the highest corresponding optical birefringence of a crystal without the dopant is disclosed. Among the useful crystals are crystals consisting essentially of doped MTiOXO.sub.4 containing at least about 100 ppm Ta.
    Type: Grant
    Filed: December 23, 1992
    Date of Patent: May 10, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, Lap K. Cheng, Lap-Tak A. Cheng
  • Patent number: 5266092
    Abstract: There is disclosed an optical waveguide comprising a K.sub.1-x Rb.sub.x TiOmO.sub.4 single crystal substrate, wherein x is from 0 to 1 and M is P or As, having at least one optically smooth surface wherein sufficient K.sup.+ and/or Rb.sup.+ have been replaced by ions selected from at least one of H.sup.+ and NH.sub.4.sup.+ and, optionally, at least one monovalent ion selected from Rb.sup.+, Cs.sup.+, Tl.sup.+, and/or at least one divalent ion selected from Ba.sup.+2, Sr.sup.+2, Ca.sup.+2 and Pb.sup.+2 to chance the surface index of refraction at least a 0.00025 with respect to the index of refraction of the single crystal substrate. One process disclosed for producing an optical waveguide comprises the steps of contacting at least one optically smooth surface of a single crystal of K.sub.1-x Rb.sub.x TiOmO.sub.4 with an ion exchange medium capable of supplying said replacement ions, at a temperature of from about 100.degree. C. to about 600.degree. C.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: November 30, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, August Ferretti, Mark G. Roelofs
  • Patent number: 5243676
    Abstract: Segmented waveguides for wavelength conversion (e.g., waveguides comprising alternating sections of crystalline substrate having the formula K.sub.1-x Rb.sub.x TiOMO.sub.4 where x is from 0 to 1 and M is P or As and sections of substrate material in which cations of said substrate have been partially replaced) and devices and processes employing segmented waveguides for wavelength conversion are disclosed wherein a periodic structure along the waveguide provides a Bragg reflection having a wavelength essentially equal to the wavelength of the input wave used for wavelength conversion. Also disclosed is a process for preparing a channel waveguide for a wavelength conversion system wherein areas along a portion of a crystal substrate surface used for forming the desired channel are alternately masked and unmasked during cation replacement by immersion in a molten salt.
    Type: Grant
    Filed: September 19, 1991
    Date of Patent: September 7, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, William Bindloss, Fredrik Laurell, Jerald D. Lee
  • Patent number: 5157754
    Abstract: Articles and process for wavelength conversion are disclosed which use a series of aligned sections of optical materials for wavelength conversion selected from materials having the formula K.sub.1-x Rb.sub.x TiOMO.sub.4 where x is from 0 to 1 and M is selected from P and As and materials of said formula wherein the cations of said formula have been partially replaced by at least one of Rb.sup.+, Tl.sup.+ and Cs.sup.+, and at least one of Ba.sup.++, Sr.sup.++ and Ca.sup.++. The series of sections is characterized with regard to a change in nonlinear optical coefficient, section length, and section .DELTA.k (i.e., the difference between the sum of the propagation constants for the incident waves and the sum of the propagation constants for the waves generated). The sections are selected such that the sum for the series of the product of the length of each section with the .DELTA.k is equal to about 2.pi.
    Type: Grant
    Filed: July 18, 1991
    Date of Patent: October 20, 1992
    Assignee: E. I. Du Pont de Nemours
    Inventors: John D. Bierlein, Joseph B. Brown, III, Carolus J. van der Poel
  • Patent number: 5146533
    Abstract: There is disclosed an optical waveguide comprising a K.sub.1-x Rb.sub.x TiOMO.sub.4 single crystal substrate, wherein x is from 0 to 1 and M is P or As, having at least one optically smooth surface wherein sufficient K.sup.+ and/or Rb.sup.+ have been replaced by ions selected from at least one of H.sup.+ and NH.sub.4.sup.+ and, optionally, at least one monovalent ion selected from Rb.sup.+, Cs.sup.+, Tl.sup.+, and/or at least one divalent ion selected from Ba.sup.+2, Sr.sup.+2, Ca.sup.+2 and Pb.sup.+2 change the surface index of refraction at least about 0.00025 with respect to the index of refraction of the single crystal substrate. One process disclosed for producing an optical waveguide comprises the steps of contacting at least one optically smooth surface of a single crystal of K.sub.1-x Rb.sub.x TiOMO.sub.4 with an ion exchange medium capable of supplying said replacement ions for sufficient time at a temperature of from about 100.degree. C. to about 600.degree. C., and cooling the resulting crystal.
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: September 8, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, August Ferretti, Mark G. Roelofs
  • Patent number: 5084206
    Abstract: A composition is disclosed which consists essentially of doped crystalline MTiOXO.sub.4 (wherein M is selected from the group consisting of K, Rb and Tl, X is selected from the group consisting of P and As) which contain at least about 100 ppm total of at least one dopant selected from the group consisting of Ga, Al and Si. The compositions generally have low ionic conductivity, and may be prepared using an improved flux process wherein Ga, Al and/or Si dopant is added to the flux in a total amount of at least about 0.5 mole % and the crystallization temperature is controlled to provide a crystalline composition containing the desired amount of dopant.
    Type: Grant
    Filed: February 2, 1990
    Date of Patent: January 28, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Albert A. Ballman, John D. Bierlein, August Ferretti, Thurman E. Gier, Patricia A. Morris
  • Patent number: 5028107
    Abstract: Articles and process for wavelength conversion are disclosed which use a series of aligned sections of optical materials which are suitably balanced over the series with regard to the section length and the section .DELTA.k (i.e. the difference between the sum of the propagation constants for the incident waves and the sum of the propagation constants for the waves generated). The sections are selected such that the sum for the series of the product of the length of each section with the .DELTA.k is equal to about zero, and the length of each section is less than its coherence length. Embodiments are disclosed wherein at least one of the optical materials is optically nonlinear and/or wherein a layer of nonlinear optical material is provided adjacent to the series of sections.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: July 2, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, Daniel B. Laubacher
  • Patent number: 4766954
    Abstract: There is disclosed a process for producing an optical waveguide comprising contacting at least one optically smooth surface of a single crystal of K.sub.1-x Rb.sub.x TiOMO.sub.4 wherein x is from 0 to 1 and M is P or As with a specified molten salt of at least one of Rb, Cs and Tl at a temperature of from about 200.degree. C. to about 600.degree. C. for a time sufficient to increase the surface index of refraction at least about 0.00025 with respect to the index of refraction of the starting crystal, and cooling the resulting crystal. The product made thereby and a waveguide device using the same are also disclosed.
    Type: Grant
    Filed: December 11, 1987
    Date of Patent: August 30, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, Lothar H. Brixner, August Ferretti, William Yang-Hsing Hsu
  • Patent number: 4740265
    Abstract: There is disclosed a process for producing an optical waveguide comprising contacting at least one optically smooth surface of a single crystal of K.sub.1-x Rb.sub.x TiOMO.sub.4 wherein x is from 0 to 1 and M is P or As with a specified molten salt of at least one of Rb, Cs and Tl at a temperature of from about 200.degree. C. to about 600.degree. C. for a time sufficient to increase the surface index of refraction at least about 0.00025 with respect to the index of refraction of the starting crystal, and cooling the resulting crystal. The product made thereby and a waveguide device using the same are also disclosed.
    Type: Grant
    Filed: January 8, 1987
    Date of Patent: April 26, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bierlein, Lothar H. Brixner, August Ferretti, William Y. Hsu