Patents by Inventor Chun Ju Youn

Chun Ju Youn 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: 20190353918
    Abstract: Provided is a polarization decomposition device. The polarization decomposition device includes a polarization beam splitter configured to split an optical signal into a first polarized light having a first polarization direction and a second polarized light having a second polarization direction different from the first polarized light, a phase shifter configured to delay a phase of the first polarized light, a polarization rotator configured to rotate the second polarized light so that the polarization direction of the second polarized light is changed, and an interference beam splitter configured to allow the first polarized light in which the phase is delayed and the second polarized light in which the polarization direction is rotated to interfere with each other and split them into a third polarized light and a fourth polarized light.
    Type: Application
    Filed: May 17, 2019
    Publication date: November 21, 2019
    Inventors: Kap-Joong KIM, Chun Ju YOUN, Heasin KO, Byung-Seok CHOI, Joong-Seon CHOE
  • Publication number: 20190162986
    Abstract: Provided is an apparatus configured to split light into a plurality of polarizations, the apparatus including an input waveguide configured to receive the light, a first interferometer configured to split the light into a first polarization and a second polarization, and a second interferometer configured to split the light into a third polarization and a fourth polarization, wherein the first interferometer and the second interferometer are connected in parallel, the first interferometer comprises a first output waveguide configured to output the first polarization, and a second output waveguide configured to output the second polarization, and the second interferometer comprises a third output waveguide configured to output the third polarization, and a fourth output waveguide configured to output the fourth polarization.
    Type: Application
    Filed: November 8, 2018
    Publication date: May 30, 2019
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Joong-Seon Choe, Chun Ju Youn, Heasin Ko, Kap-Joong Kim, Byung-seok Choi
  • Patent number: 9893810
    Abstract: There is provided a receiver optical module including a photodetector having a plurality of channels, a capacitor disposing block formed on an upper portion of the photodetector, a plurality of capacitors formed on the capacitor disposing block, and an electrical wiring configured to connect the plurality of capacitors to electrodes of a plurality of channels of the photodetector, wherein the plurality of capacitors are formed on the capacitor disposing block such that distance between the capacitors and the electrodes of the corresponding channels are the same. Distortion and loss of signal characteristics of high frequency can be reduced and quality of a signal can be enhanced.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: February 13, 2018
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Seo Young Lee, Young Tak Han, Jong Hoi Kim, Joong Seon Choe, Chun Ju Youn, Hyun Do Jung
  • Patent number: 9710231
    Abstract: A multiple output quantum random number generator coherently measures an optical source noise and outputs a random number sequence based on the independent and coherent measurement of optical source noise. Therefore, it is possible to output a random number sequence at a high speed and to perform multiple outputs.
    Type: Grant
    Filed: May 2, 2016
    Date of Patent: July 18, 2017
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Chun Ju Youn, Joong Seon Choe, Jong Hoi Kim
  • Publication number: 20160335054
    Abstract: A multiple output quantum random number generator coherently measures an optical source noise and outputs a random number sequence based on the independent and coherent measurement of optical source noise. Therefore, it is possible to output a random number sequence at a high speed and to perform multiple outputs.
    Type: Application
    Filed: May 2, 2016
    Publication date: November 17, 2016
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Chun Ju YOUN, Joong Seon CHOE, Jong Hoi KIM
  • Publication number: 20160336368
    Abstract: There is provided a receiver optical module including a photodetector having a plurality of channels, a capacitor disposing block formed on an upper portion of the photodetector, a plurality of capacitors formed on the capacitor disposing block, and an electrical wiring configured to connect the plurality of capacitors to electrodes of a plurality of channels of the photodetector, wherein the plurality of capacitors are formed on the capacitor disposing block such that distance between the capacitors and the electrodes of the corresponding channels are the same. Distortion and loss of signal characteristics of high frequency can be reduced and quality of a signal can be enhanced.
    Type: Application
    Filed: April 20, 2016
    Publication date: November 17, 2016
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Seo Young LEE, Young Tak HAN, Jong Hoi KIM, Joong Seon CHOE, Chun Ju YOUN, Hyun Do JUNG
  • Patent number: 9270381
    Abstract: Disclosed are a method and an apparatus for transmitting and receiving coherent optical OFDM.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: February 23, 2016
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Chun Ju Youn, Yong-Hwan Kwon, Duk Jun Kim, Jong-Hoi Kim, Joong-Seon Choe, Kwang-Seong Choi, Eun Soo Nam
  • Patent number: 9166680
    Abstract: Provided is an apparatus and method for measuring IQ imbalance, and in particular, is an apparatus and method for measuring IQ imbalance for an optical receiver. The apparatus for measuring IQ imbalance for an optical receiver includes a light generating unit generating optical and reference signals to provide the optical and reference signals to an optical receiver, a graph creating unit creating a Lissajous figure by using an in-phase (I) signal and a quadrature-phase (Q) signal output from the optical receiver in response to the optical and reference signals, and a calculating unit calculating IQ imbalance for the optical receiver with reference to the Lissajous figure.
    Type: Grant
    Filed: September 16, 2013
    Date of Patent: October 20, 2015
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Chun Ju Youn, Jong-Hoi Kim, Joong-Seon Choe, Duk Jun Kim, Yong-Hwan Kwon, Eun Soo Nam
  • Patent number: 9031421
    Abstract: Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measurable range.
    Type: Grant
    Filed: July 3, 2013
    Date of Patent: May 12, 2015
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Joong-Seon Choe, Chun Ju Youn, Jong-Hoi Kim, Duk Jun Kim, Yong-Hwan Kwon, Kwang-Seong Choi, Eun Soo Nam
  • Patent number: 8929731
    Abstract: An apparatus for measuring performance of a coherent optical receiver includes a beam splitter splitting light into first and second paths, a first optical modulator modulating the first path light, a variable optical attenuator controlling an optical power of the first optical modulator, a first polarization controller transmitting a signal controlling polarization of an output of the variable optical attenuator to the coherent optical receiver, a second optical modulator modulating the second path light, a variable optical delay line delaying time of an output of the second optical modulator, a second polarization controller transmitting a signal controlling polarization of an output of the variable optical delay line to the coherent optical receiver, a network analyzer measuring performance of the coherent optical receiver and controlling the optical modulators, and a controller transmitting a control signal to the optical modulators.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: January 6, 2015
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Chun Ju Youn, Joong-Seon Choe, Jong-Hoi Kim, Duk Jun Kim, Yong-Hwan Kwon, Eun Soo Nam
  • Publication number: 20140205280
    Abstract: Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measureable range.
    Type: Application
    Filed: July 3, 2013
    Publication date: July 24, 2014
    Inventors: Joong-Seon CHOE, Chun Ju YOUN, Jong-Hoi KIM, Duk Jun KIM, Yong-Hwan KWON, Kwang-Seong CHOI, Eun Soo NAM
  • Publication number: 20140169786
    Abstract: Provided is an apparatus and method for measuring IQ imbalance, and in particular, is an apparatus and method for measuring IQ imbalance for an optical receiver. The apparatus for measuring IQ imbalance for an optical receiver includes a light generating unit generating optical and reference signals to provide the optical and reference signals to an optical receiver, a graph creating unit creating a Lissajous figure by using an in-phase (I) signal and a quadrature-phase (Q) signal output from the optical receiver in response to the optical and reference signals, and a calculating unit calculating IQ imbalance for the optical receiver with reference to the Lissajous figure.
    Type: Application
    Filed: September 16, 2013
    Publication date: June 19, 2014
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Chun Ju YOUN, Jong-Hoi KIM, Joong-Seon CHOE, Duk Jun KIM, Yong-Hwan KWON, Eun Soo NAM
  • Patent number: 8693459
    Abstract: Provided is a polarization division multiplexed optical OFDM transmitter. The polarization division multiplexed optical OFDM transmitter includes a data demultiplexer, a training symbol generation unit and an optical up-converter and polarization division multiplexing unit. The data demultiplexer divides a transmission signal into a plurality of groups. The training symbol generation unit allocates a plurality of training symbols for each OFDM data which is included in the respective multiplexed groups, and allocates repetitive data in a time domain for the respective training symbols for data of 0 to periodically appear for the respective training symbols in a frequency domain. The optical up-converter and polarization division multiplexing unit performs optical frequency band conversion and polarization division multiplexing on an output of the training symbol generation unit to output a polarization division multiplexed optical OFDM signal corresponding to a plurality of polarization components.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: April 8, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Chun Ju Youn, Yong-Hwan Kwon, Jong-Hoi Kim, Joong-Seon Choe, Kwang-Seong Choi, Kyoungwoo Heo, Eun Soo Nam
  • Publication number: 20130308949
    Abstract: Provided is an optical OFDM receiver. The optical OFDM receiver receives an optical signal dependent on the nonlinearity of a transmitter. The optical OFDM receives includes an optical down converter, a nonlinearity compensator, and an OFDM demodulator. The optical down converter converts the optical signal into an electrical signal. The nonlinearity compensator filters the electrical signal, for compensating distortion which is added to the optical signal when the transmitter performs optical modulation. The OFDM demodulator demodulates the distortion-compensated electrical signal in an OFDM scheme.
    Type: Application
    Filed: July 25, 2013
    Publication date: November 21, 2013
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Chun Ju YOUN, Yong-Hwan KWON, Eun Soo NAM, Jong-Hoi KIM, Joong-Seon CHOE, Kwang-Seong CHOI
  • Patent number: 8521040
    Abstract: Provided is an optical OFDM receiver. The optical OFDM receiver receives an optical signal dependent on the nonlinearity of a transmitter. The optical OFDM receives includes an optical down converter, a nonlinearity compensator, and an OFDM demodulator. The optical down converter converts the optical signal into an electrical signal. The nonlinearity compensator filters the electrical signal, for compensating distortion which is added to the optical signal when the transmitter performs optical modulation. The OFDM demodulator demodulates the distortion-compensated electrical signal in an OFDM scheme.
    Type: Grant
    Filed: May 4, 2010
    Date of Patent: August 27, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Chun Ju Youn, Yong-Hwan Kwon, Eun Soo Nam, Jong-Hoi Kim, Joong-Seon Choe, Kwang-Seong Choi
  • Patent number: 8477939
    Abstract: Provided are an apparatus for receiving a quantum cryptographic key and an apparatus for transmitting and receiving a quantum cryptographic key at high speed without polarization drift of an optical pulse signal and phase drift of an interferometer. The apparatus for receiving a quantum key includes: a polarization-insensitive optical phase modulator parts for receiving an optical pulse signal, and modulating and outputting a phase of the optical pulse signal without being affected by the polarization state of the optical pulse signal; an asymmetric Mach-Zehnder interferometer for causing interference in and outputting the optical pulse signal received from the polarization-insensitive optical phase modulator parts; and a photon detectors for detecting the optical pulse signal received from the asymmetric Mach-Zehnder interferometer.
    Type: Grant
    Filed: November 28, 2007
    Date of Patent: July 2, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Chun Ju Youn, Tae Gon Noh
  • Publication number: 20130156362
    Abstract: Provided is a core which reduces optic splice loss between discontinuous optical waveguides.
    Type: Application
    Filed: September 12, 2012
    Publication date: June 20, 2013
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Duk Jun KIM, Jong-Hoi Kim, Joong-Seon Choe, Chun Ju Youn, Kwang-Seong Choi, Yong-Hwan Kwon, Eun Soo Nam
  • Publication number: 20130156394
    Abstract: The inventive concept relates to an optical communication module. The optical communication module may include a metal block: an electrical device formed on the metal block; an optical device adhesive block formed on the metal block; an optical device formed on the optical device adhesive block and connected to the electrical device through a bonding interconnection; and a flat type optical waveguide formed on one side of the optical device adhesive block and optically aligned with the optical device.
    Type: Application
    Filed: September 12, 2012
    Publication date: June 20, 2013
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Joong-Seon CHOE, Jong-Hoi Kim, Kwang-Seong Choi, Chun Ju Youn, Duk Jun Kim, Yong-Hwan Kwon, Eun Soo Nam
  • Patent number: 8272789
    Abstract: Provided are an adapter assembly and method for compensating optical fibers for a length difference. The adapter assembly includes a first adapter, a second adapter, and a member. The first adapter is configured to be connected to at least one optical communication unit. The second adapter is configured to be connected to at least another optical communication unit and be coupled to the first adapter. The member is configured to be interposed between the first and second adapters for providing an optical signal transmission path between the optical communication units. Owing to the member, a length difference between optical fibers can be compensated for.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: September 25, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Joong-Seon Choe, Yong-Hwan Kwon, Chun Ju Youn, Jong-Hoi Kim, Kwang-Seong Choi, Eun Soo Nam
  • Patent number: 8265279
    Abstract: Provided is a polarization coding quantum cryptography system. The quantum cryptography includes a light source, a quantum channel, an optical path selector, and a path-dependent polarization selector. The light source generates a signal light. The quantum channel is used as a path to transmit the signal light to a receiver unit. The optical path selector is disposed between the light source and the quantum channel to transmit the signal light to one of a plurality of propagation paths. The path-dependent polarization selector is disposed between the optical path selector and the quantum channel. Herein, the path-dependent polarization selector is configured to determine the polarization direction of the signal light according to the propagation path of the signal light.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: September 11, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Chun-Ju Youn, Tae-Gon Noh