Patents Represented by Attorney Richard D. Lauman

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  • Loss stabilized buried heterostructure laser
    Patent number: 4481631
    Abstract: A buried heterostructure laser which obtains lowest mode operation by larger differences in loss between the lowest and higher order modes is described. The loss is achieved by interface scattering between the mesa and the burying layer. The scattering losses increase with refractive index discontinuity, interface roughness and decreasing mesa width. Stabilization results because scattering losses increase rapidly with the order of the transverse modes.
    Type: Grant
    Filed: June 12, 1981
    Date of Patent: November 6, 1984
    Assignee: AT&T Bell Laboratories
    Inventors: Charles H. Henry, Ralph A. Logan
  • Surface gratings and a method of increasing their spatial frequency
    Patent number: 4321282
    Abstract: A method is described for increasing the spatial frequency of surface relief structures. Periods as small as 750 Angstroms have been made.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: March 23, 1982
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventor: Leo F. Johnson