Electronics and Telecommunications Research Institute

Intellectual Discovery Co., Ltd.

Mun Seob Lee

Sung Chang Kim

Dong Soo Lee

Hark Yoo

Geun Yong Kim

Jong Deog Kim

Young Suk Lee

Young Sun Kim

Bin Yeong Yoon

Gi Hyeon Min

Sung Woong Park

Dongsoo Lee

Hyun Seo Kang

Jai Sang Koh

Byung-Tak Lee

Byung Tak Lee

Youngsuk Lee

Bong Tae Kim

Young Soon Heo

Hyoung Jun Park

Ji Hyoung Ryu

Keo Sik Kim

Chan Il Yeo

Dong Hoon Son

Sim-Kwon Yoon

Si Woong Park

Kye Eun Kim

Nack Woo Kim

Sim Kwon Yoon

Jeong Eun Kim

Bong Kyu Kim

Young Tak Han

Nac Woo Kim

Seihyoung Lee

Dae Won Choi

Provided are an apparatus and method for adjusting an optical axis. In the apparatus, an iris diaphragm and a quadrant photodiode (QPD) are used to align optical axes of an optical system of the apparatus so that optical transmission efficiency between an optical transmitter and an optical receiver can be increased. Since a hole of the iris diaphragm can be adjusted to be small, a beam larger than a light-receiving area of the QPD can be included in the light-receiving area, and optical axis alignment is facilitated accordingly. When the QPD and the iris diaphragm are applied to the apparatus, it is possible to simultaneously perform data transmission, tracking, and optical axis alignment. An optical fiber end surface and optical axes of lenses arranged in parallel are aligned in the apparatus so that alignment between two terminals can be easy and reception efficiency can be increased.

Apparatus and method for adjusting optical axis for optical wireless communication in free space

A hologram image acquiring apparatus includes a linear polarizer that filters incident light reflected by an object into a polarized component of a specific angle; a spherical lens that partially converts light that is incident through the linear polarizer to a spherical waveform; and a phase shifter that converts a part of the light incident through the spherical lens to a plane waveform having a respective phase per pixel unit.

Apparatus and method for hologram image acquisition

A wireless optical communication apparatus for performing bi-directional optical transmission in a free space includes a first optical system configured to transmit data through a downlink scheme and a second optical system configured to receive the data from the first optical system and transmit a control signal to the first optical system through an uplink scheme, wherein each of the first optical system and the second optical system transmits and receives the data and the control signal through a single port.

Bi-directional wireless optical communication apparatus and method thereof

There are provided an image processing device and a processing method thereof. The image processing method includes obtaining an interference signal using a sample beam and a reference beam, transforming the interference signal by using a numerical signal processing method or an intensity mixing method to generate a transformed interference signal, and obtaining a three-dimensional (3D) phase image by using the interference signal and the transformed interference signal.

Image processing device and processing method thereof

An imaging sensor includes at least one fiber Bragg grating for filtering an image from a subject for wavelength bands, and an imaging device for converting an image transmitted through the fiber Bragg grating into a digital signal.

Imaging sensor with Bragg filter and method of manufacturing the same

Provided are an apparatus and method for recognizing an object on the basis of property information on an object obtained using a multi-wavelength spectrometer. An apparatus for recognizing an object using a multi-wavelength spectrometer includes an image processing unit configured to extract an region of interest from an input three-dimensional image and output shape information on the region of interest, a light irradiation unit configured to irradiate light of a plurality of wavelengths to an arbitrary position of an object corresponding to the detected region of interest, a light receiving unit configured to measure a spectrophotometric value for each light of the plurality of wavelengths, and a light processing unit configured to generate a differential spectrophotometric map using a differential value between spectrophotometric values of different wavelengths measured at the same light irradiation position, and recognize the object using the differential spectrophotometric map and the shape information.

Object recognition apparatus using spectrometer and method thereof

An optical network system for controlling a passive optical network (PON) in which at least one symmetric optical subscriber terminal and at least one asymmetric optical subscriber terminal coexist is provided.

Optical network system and method for controlling optical network system

A Passive Optical Network (PON)-based system and method for providing handover between Optical Network Terminals (ONTs) are provided. The PON-based system may include an Optical Line Terminal (OLT), and an ONT to relay communication between the OLT and a mobile terminal. When the mobile terminal is connected to the ONT, the ONT may transmit a WiFi location update alarm message to the OLT, and the OLT may update a Look-Up Table (LUT) in response to the WiFi location update alarm message.

Passive optical network (PON)-based system and method for providing handover among optical network terminals (ONTs)

An apparatus and method for monitoring an optical line is provided. The optical line monitoring apparatus may include a comparison unit to extract first identification information about an optical network terminal (ONT) from reflected data that is reflected and received from the optical line, and to compare the extracted first identification information to predetermined second identification information about the ONT, and a processor to analyze a state of the optical line using the reflected data when the first identification information is identical to the second identification information.

Apparatus and method for monitoring optical line

Provided is an optical line terminator (OLT) to recover packet data and a clock from an optical signal including a silent interval. The OLT may receive packet data and a clock from at least one optical network unit (ONU). Even in a silent interval in which the at least one ONU does not transmit packet data, the OLT may successfully recover the clock.

Method and apparatus for burst mode clock and data recovery

An apparatus and method for managing a dynamic bandwidth allocation to support a low-power mode, in a passive optical network (PON) are provided. The apparatus may include a power saving mode managing unit to manage a power saving mode of at least one optical network unit (ONU), a bandwidth allocation parameter storage unit to store a bandwidth allocation parameter used for a power saving mode, and to maintain the stored bandwidth allocation parameter, and a dynamic bandwidth allocating unit to provide bandwidth allocation information to the at least one ONU, when the stored bandwidth allocation parameter is received.

Apparatus and method for managing dynamic bandwidth allocation to support low-power mode in passive optical network (PON)

An optical subscriber network for power reduction is provided. The optical subscriber network may include an Optical Line Terminal (OLT) and an Optical Network Terminal (ONT). The OLT may manage a plurality of ONTs by classifying the plurality of ONTs into a sleep group, and may multicast a sleep allowance message only to ONTs included in a predetermined sleep group.

Optical subscriber network

A method and apparatus of detecting a rogue optical network unit (ONU) is provided. An optical line terminal (OLT) detects an abnormal upstream transmission to determine a plurality of rogue ONU candidates, and transmits a sleep allow message instructing a transition to a sleep mode to each of the plurality of rogue ONU candidates. The OLT detects the rogue ONU among the plurality of rogue ONU candidates based on upstream transmissions from the plurality of rogue ONU candidates in the sleep mode. Since the detection of the rogue ONU is performed in the sleep mode, the remaining ONUs can transition from the sleep mode to the normal mode after the detection of the rogue ONU is completed, thereby making it possible to rapidly resume upstream communication.

Detecting rogue ONU, OLT and PON system

Disclosed is an optical amplifier which includes an upward optical amplifier configured to amplify an input upward optical signal of an input optical signal; and a control circuit configured to control an operation of the upward optical amplifier according to whether an upward stream is detected from the input upward optical signal.

Optical repeater and optical signal amplifying method thereof

A method of transmitting an Operations, Administration and Maintenance (OAM) message and of processing an error in a Passive Optical Network (PON) system is provided. Using an OAM packet format that may be used in common in the PON system, a process of transmitting or receiving an OAM message may be simplified, an efficiency of the process may be increased, and an Optical Network Unit (ONU) may be managed at a high speed.

Growing community of inventors

Daejeon, South Korea

Mun Seob Lee