Patents by Inventor Yoshitaka Furukawa

Yoshitaka Furukawa 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: 4128815
    Abstract: In single transverse mode semiconductor lasers, a semiconductor laser which comprises an optical confinement semiconductor layer having a refractive index of n.sub.3, an active layer of an optical waveguide having a refractive index of n.sub.1 and formed on said semiconductor layer, a buffer layer having a refractive index of n.sub.2 and formed on said active layer, a mode controlling striped semiconductor layer having a refractive index of n.sub.6 and formed on said buffer layer and opposing contacts, and is controllable in the transverse mode in the relations ofn.sub.6 .ltoreq.n.sub.2 <n.sub.1 and n.sub.3 <n.sub.1.
    Type: Grant
    Filed: September 23, 1976
    Date of Patent: December 5, 1978
    Assignee: Nippon Telegraph and Telephone Public Corp.
    Inventors: Hitoshi Kawaguchi, Yoshitaka Furukawa
  • Patent number: 4030949
    Abstract: Disclosed is a method of yielding a multilayer-liquid phase epitaxial growth of Al.sub.x Ga.sub.1.sub.-x As and GaAs for manufacturing a double heterostructure laser, light emitting diode, etc., which is characterized in that hydrogen gas or inert gas, containing GaCl gas, is used as an atmosphere for the epitaxial growth. This method permits the liquid phase epitaxial growth of a semiconductor layer even on an Al.sub.x Ga.sub.1.sub.-x As (x .gtoreq. 0.3) which is once exposed to the air or subjected to an etching treatment. Accordingly, this method is suitable for the manufacture of a semiconductor element having a buried active layer. This method also permits the manufacture of an epitaxial wafer having a low dislocation density.
    Type: Grant
    Filed: June 26, 1975
    Date of Patent: June 21, 1977
    Assignee: Nippon Telegraph and Telephone Public Corporation
    Inventors: Yoshiji Horikoshi, Yoshitaka Furukawa