Patents by Inventor Eric Gung-Hwa Lean

Eric Gung-Hwa Lean 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).

  • Publication number: 20020085264
    Abstract: The present invention pertains to a polarization independent tunable acousto-optical filter and the corresponding method. The filter diffracts an input light beam into a first input light beam unaffected by acoustic waves and a second input light beam affected by acoustic waves. A polarization beam displacer/combiner is employed to separate the input light beam into two orthogonal beams. Several polarized rotators are used to rotate the polarization of light by 90 degrees. An acousto-optical device makes the polarization of light with a particular wavelength rotate by 90 degrees. The two beams are then properly combined to form orthogonal beams. The filtering method has nothing to do with the polarization of the incident light. The filter has such advantages as a high extinction ratio, a small volume and a lower cost.
    Type: Application
    Filed: March 8, 2001
    Publication date: July 4, 2002
    Inventors: Eric Gung-Hwa Lean, Chen-Bin Huang, Wei-Jen Chou, Shu-Mei Yang, Chieh Hu
  • Patent number: 6404536
    Abstract: The present invention pertains to a polarization independent tunable acousto-optical filter and the corresponding method. The filter diffracts an input light beam into a first input light beam unaffected by acoustic waves and a second input light beam affected by acoustic waves. A polarization beam displacer/combiner is employed to separate the input light beam into two orthogonal beams. Several polarized rotators are used to rotate the polarization of light by 90 degrees. An acousto-optical device makes the polarization of light with a particular wavelength rotate by 90 degrees. The two beams are then properly combined to form orthogonal beams. The filtering method has nothing to do with the polarization of the incident light. The filter has such advantages as a high extinction ratio, a small volume and a lower cost.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: June 11, 2002
    Assignee: Industrial Technology Research Institute
    Inventors: Eric Gung-Hwa Lean, Chen-Bin Huang, Wei-Jen Chou, Shu-Mei Yang, Chieh Hu
  • Patent number: 4084191
    Abstract: A scanning apparatus for converting an optical line image to a serial electrical analog signal by launching an acoustic wave in a plurality of ridged waveguides each of a different length. In one embodiment the launching transducer includes an electro-optical layer which modulates the acoustic wave as a function of the incident light intensity. In a second embodiment the acoustic wave is launched in each waveguide with the same amplitude but interacts with an acousto-optical overlay on the waveguide to amplitude modulate the intensity of the propagating acoustic wave. The thus generated and modulated acoustic waves are converted to electrical signals either by reflection back to the launching transducer or by individual transducers on each channel. The differing lengths converts the parallel image to a series electrical signal.
    Type: Grant
    Filed: December 20, 1976
    Date of Patent: April 11, 1978
    Assignee: International Business Machines Corporation
    Inventor: Eric Gung-Hwa Lean
  • Patent number: 4084189
    Abstract: A thin film optical scanner using phonon echoes. A piezoelectric (an insulator or a semiconductor) crystal has deposited thereon a photoconductor. An acoustic transducer propagates a broad strain wave pulse guided in or on the crystal. A relatively shorter electric field pulse is coupled to the piezoelectric crystal through the photoconductor which has an optical signal focused thereon. The interaction of electric field and strain wave produce a backward travelling acoustic wave which is modulated by the optical signal.
    Type: Grant
    Filed: December 29, 1975
    Date of Patent: April 11, 1978
    Assignee: International Business Machines Corporation
    Inventor: Eric Gung-Hwa Lean
  • Patent number: 4079404
    Abstract: An optical assembly structure wherein miniature optical components such as lasers, modulators, lenses, thin-film and fiber-optic waveguides, and photodetectors are critically aligned and supported for coactive operation by means of two or more wafers which are formed with complementary grooves and mortises to support the loose optical components such as lenses and fiber-optic waveguides and to receive alignment rails to insure the relativity of the wafers, which also have formed integral therewith optical elements such as waveguides, modulators, and lasers, to produce an integrated optical assembly somewhat in the manner of an "optical bench," wherein the bench structure also provides an active optical element.
    Type: Grant
    Filed: December 30, 1976
    Date of Patent: March 14, 1978
    Assignee: International Business Machines Corporation
    Inventors: Liam David Comerford, John David Crow, Robert Allan Laff, Eric Gung-Hwa Lean, Michael John Brady
  • 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
  • Patent number: 3994559
    Abstract: An optical structure for the bidirectional coupling of light between each of a multiplicity of optical fibers and corresponding individual thin-film waveguides to achieve a leaky wave coupling from one guided mode structure to a second guided mode structure. The structure is particularly suited for fabrication by planar deposition and etching techniques and features the precise axial alignment of the optical elements by inserting the fibers in etched V-grooves in the substrate upon which are deposited the waveguides.
    Type: Grant
    Filed: December 22, 1975
    Date of Patent: November 30, 1976
    Assignee: International Business Machines Corporation
    Inventors: John David Crow, Eric Gung-Hwa Lean