Patents Represented by Law Firm Kelfgott & Karas
  • Optical coupler ultizing prisms
    Patent number: 5125053
    Abstract: An optical coupler is disclosed which couples a signal beam and a pumping beam having proximate wavelengths to each other. The optical coupler includes a first prism having an included angle of 45 degrees, and a triangular prism having an apex angle of 22.5 degrees and adhered to a face of the first prism on which an optical wavelength multiplexing film is formed. The signal beam and the pumping beam multiplexed by the optical coupled is introduced into an Er doped fiber, in which the signal beam is amplified directly.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: June 23, 1992
    Assignee: Fujitsu Limited
    Inventors: Kenichi Abe, Norihisa Naganuma, Hisashi Takamatsu