Patents by Inventor Bun Lee

Bun Lee 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: 6181843
    Abstract: The present invention is related to a surface transmission-type optical switch of the 1-D array method, and more particularly to a surface transmission-type optical switch, which is manufactured by Fabry-perot type not to need optical waveguides and integrated only by amplifiers of the space division multiplex. A surface transmission-type optical switch according to the present invention is a structure to overlap 3 optical amplifiers for optical switching, and an incoming signal beam is amplified through the first optical amplifier and becomes an n×n amplifiers of a matrix type with the second signal amplification, passing through the second optical amplifier overlapped on the first amplifier. Amplified signal beams through 2 amplifiers perform n×n matrix switching through the third amplifier, and go out to the opposite side of the incoming surface.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: January 30, 2001
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bun Lee, Jong Hyeob Baek
  • Patent number: 5976903
    Abstract: A method for making a surface-type semiconductor laser specially devised to keep the stability of the wavelength at the next generation laser for WDM, which does not cause a raising characteristic variation with time because the laser wavelength of the individual device can be controlled easily and exactly as required and the devices in which the wavelength control have completed is stable in their material properties. The surface-type semiconductor laser is made by growing the cladding layer within the active layer at a low temperature, growing the upper and the underlying superlattice mirror layers and the quantum well structure within the active layer at a high temperature and then sintering the structure thus formed at a high temperature.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: November 2, 1999
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bun Lee, Jong Hyub Baek
  • Patent number: 5900056
    Abstract: The present invention relates to a method for growing new binary, ternary and quaternary epitaxial layers of III-V compound semiconductors which have the characteristics of low temperature growth, good stability and high-purity, using remote plasma, comprising the steps of converting H.sub.2 and He mixed gas into a plasma state; heating a high-purity of solid source to generate a vaporized source; reacting the vaporized source with H.sub.2 under the H.sub.2 and He plasma environment to produce V-hydrides in situ; introducing the V-hydrides directly into group III source without passing through the plasma; and reacting V-hydrides with group III source on a substrate to form an epitaxial thin layer of III-V compound semiconductors.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: May 4, 1999
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sung-Woo Choi, Jong-Hyeob Baek, Bun Lee
  • Patent number: 5883911
    Abstract: An improved surface-emitting laser device by which the light emitting wave length can be easily varied since the electric potential grown using the thin film material having a desired lattice rate uses a very small portion of activation layers, and by which the continuous oscillation is made at room temperature by using the reflector having high reflective index. Thus, optical characteristics are increased, which includes a GaAs substrate; a lower reflector is formed of multiple layers of AlAs/GaAs heterogenous thin films having a reflective index of 1 on the GaAs substrate; a tooth-shaped grading layer is formed of a lower reflector on the lower reflector and an In.sub.x Ga.sub.1-x As thin film having a large lattice rate in a compositional grading method; a tooth-shaped InGaAs grading well is formed on the In.sub.x Ga.sub.1-x As grading layer as an In composition of which reduced rather than the grading layer; a buffer layer is formed on the In.sub.x Ga.sub.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: March 16, 1999
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bun Lee, Jong-Hyeob Baek, Sung-Woo Choi, Jin-Hong Lee
  • Patent number: 5855669
    Abstract: A grating coupler is formed by growing an optical waveguide layer on a substrate by an epitaxial growing process such as a metalorganic chemical vapor deposition and a molecular beam deposition. The optical waveguide layer has a surface on which a cross-hatch pattern serving as the grating is continuously formed. The optical waveguide layer is formed with a material having a reflective index greater than a reflective index of the substrate or an atmosphere. Specifically, the substrate is formed with GaAs and the optical waveguide layer is formed with InGaAs. Further, the substrate is an on-substrate having an orientation coinciding with a ?100! plane, so as to form the optical waveguide layer having continuous cross-hatch patterns on the surface thereof. The spacing between the cross-hatch patterns can be varied according to variation of a growth temperature of the optical waveguide layer.
    Type: Grant
    Filed: April 17, 1997
    Date of Patent: January 5, 1999
    Assignee: Electronics And Telecommunications Research Institute
    Inventors: Jong-Hyeob Baek, Bun Lee
  • Patent number: 5856206
    Abstract: A Bragg reflector with a uniform thickness is fabricated by means of an in-situ laser reflectometer. In order to fabricate the Bragg reflector, a plurality of buffer layers are formed on a semiconductor substrate. Then, first and second epitaxial layers are alternatively grown on the buffer layers. While growing the epitaxial layers, the thickness of the first and second epitaxial layers are continuously measured by using a laser beam having the same wavelength as a reflective wavelength of the Bragg reflector. In this way, the thickness of the Bragg reflector is precisely controlled according to the measurements, so that the Bragg reflector may be fabricated uniformly with a predetermined thickness.
    Type: Grant
    Filed: April 17, 1997
    Date of Patent: January 5, 1999
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jong-Hyeob Baek, Bun Lee
  • Patent number: 5748319
    Abstract: A method for sensing the completion of removal of an oxide layer from a semiconductor substrate or a super conductor by a thermal etching in real time. In the method, the time of removal of the oxide layer on the semiconductor substrate or the super conductor can ben accurately sensed. According to the method, when an oxide layer which is different from the semiconductor substrate in the refractive index is being thermally etched at a high temperature, the reflected signals of the laser beams forms a periodicity, and this periodicity is utilized so as to determine the etching rate and the time of the completion of the etching.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: May 5, 1998
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jong-Hyeob Baek, Bun Lee, Sung-Woo Choi, Jin-Hong Lee
  • Patent number: 5705403
    Abstract: A method of sensing the concentration of a doped impurity on a semiconductor in real time and a method of sensing the change of its growth rate dependent on time among the changes of the growing conditions due to doping by using a real time analysis apparatus in growing a heterostructured semiconductor by a MOCVD method. A reflecting signal during the growth by means of a real time analysis apparatus has a periodic property, an amplitude change of a reflecting signal is dependent on an absorption coefficient when an absorption exists on an epitaxial layer, an impurity concentration can be obtained by using the relation of an absorption coefficient and an impurity concentration. In addition, if each peak is independently analyzed, the respective growth rate dependent on time are measured individually, so that the reduced growth rate dependent on time of the growth rate is sensed in a carbon doped AlAs layer.
    Type: Grant
    Filed: August 13, 1996
    Date of Patent: January 6, 1998
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jong-Hyeob Baek, Bun Lee, Jin-Hong Lee, Sung-Woo Choi
  • Patent number: 5686350
    Abstract: A method for fabricating a defect-free compound semiconductor thin film on a dielectric thin film which oxidizes multi-semiconductor layers consisting of a hetero compound semiconductor thin film made of one of GaAs, InGaAs or InAs over a thin film containing a carbon impurity of a high concentration and made of AlGaAs series by an annealing at a vapor ambient, thereby rapidly growing a hetero-semiconductor thin film over a dielectric thin film made of Al.sub.2 O.sub.3 with no defect.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: November 11, 1997
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bun Lee, Mee-Young Yoon, Jong-Hyeob Baek
  • Patent number: 5472505
    Abstract: An apparatus for monitoring a film growth is disclosed, in which, when a crystalline thin film is grown by applying an MOCVD (metalorganic chemical vapor deposition method), the variation of the thickness and composition due to certain factors can be detected with real time during the film growing process, and an in-situ adjustment is possible. As the optical detector for detecting two sets of reflected beams which are reflected from the film, a silicon detector and a germanium detector are used, the former being suitable for detecting short wavelength laser beams, and the latter being suitable for detecting long wavelength laser beams. Thus two different wavelengths are detected with real time, thereby measuring the thickness and composition of the film.
    Type: Grant
    Filed: December 19, 1994
    Date of Patent: December 5, 1995
    Assignee: Electronics & Telecommunications Research Institute
    Inventors: Bun Lee, Dug-Bong Kim, Jong-Hyeob Baek
  • Patent number: 5456206
    Abstract: A method for growing a thin InGaAs or InAlAs layer with heavy lattice mismatching on a GaAs substrate by a MOCVD process is described. A first material gas is injected by a MOCVD process to grow a buffer layer on a GaAs substrate to a prescribed thickness. After stopping the injection of the first material gas for a few seconds, a second material gas containing a column III element is injected at a prescribed temperature. A third material gas containing a column V element is injected to grow, on the buffer layer, a thin metallic layer of a binary compound containing the column III element of a high concentration to a thickness of 2 nm or less. After a prescribed time from the injection of the third material gas, In and Ga gases or In and Al gases, mixed in the prescribed proportion are injected in an atmosphere of said third material gas to grow a thin InGaAs or InAlAs layer on the thin metallic layer.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: October 10, 1995
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bun Lee, Mee-Young Yoon, Jong-Hyeob Baek
  • Patent number: D437325
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: February 6, 2001
    Assignee: Hewlett Packard Company
    Inventors: Tom J Searby, David Kwock Bun Lee, Peter Wyatt-Brandenburg, John Kevin Clay, Niklas L Gustavsson, Vincent Razo
  • Patent number: D386509
    Type: Grant
    Filed: June 7, 1996
    Date of Patent: November 18, 1997
    Assignee: Proxima Corporation
    Inventors: Kenneth W. Baar, Paul R. Corsaro, Lonnie C. Pogue, Brian Macowski, David Kwock Bun Lee
  • Patent number: D431245
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: September 26, 2000
    Assignee: Hewlett Packard Company
    Inventors: Tom J Searby, David Kwock Bun Lee, Peter Wyatt-Brandenburg, John Kevin Clay, Niklas L Gustavsson, Vincent Razo