Patents by Inventor Joseph Martin Blum

Joseph Martin Blum 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: 3996528
    Abstract: An injection laser, which is chemically etched to provide mirror-like surfaces, also is provided with a chirped diffraction grating. The latter grating, which is etched in the injection laser, combines with the chemically etched sides to provide laser emission in a direction substantially parallel to the current flowing through the laser. As an alternative to the chirped diffraction grating, waveguides are included in the resulting folded cavity laser. Either of the above structures relaxes the fabrication tolerance in the inclined surfaces etched in the laser relative to known folded cavity lasing structures.
    Type: Grant
    Filed: December 31, 1975
    Date of Patent: December 7, 1976
    Assignee: International Business Machines Corporation
    Inventors: Joseph Martin Blum, Eric Gung Hwa Lean, James Cleary McGroddy