Electronics and Telecommunications Research Institute

Research & Industrial Cooperation Group

Mel Telecom Inc.

Byoung Whi Kim

Tae Yeon Kim

Mahn Yong Park

Hyeong Ho Lee

Eui Suk Jung

Jeong Ju Yoo

Woo Ram Lee

Seung Hyun Cho

Jie Hyun Lee

Seung Hyun Jang

Jae Woo Yang

Geon Jeong

Chul Soo Lee

Hyun Ho Yun

Bong Tae Kim

Kang Bok Lee

Han Hyub Lee

Woo-Ram Lee

Jea Hoon Yu

Jae Dong Park

Chul Young Kim

Bong Kyu Kim

Min Ho Kang

Hyeon Ho Yoon

Yun Chur Chung

Nam Uk Kim

Youngil Park

Eui Seung Son

Sang Jo Park

Seung-Hyun Jang

Chul-Soo Lee

Jang Won Chae

Eul Suk Jung

Sung Chan Cho

Young Hee Yeon

Man Yong Park

Gil Dong Lee

Bok Rae Jung

Younghee Yeon

Sangjo Park

Chu Hwan Yim

Jung Hee Hahn

Jae Gwan Kim

An optical fiber connector embedded with a Bragg grating includes: a ferrule formed with a reception unit for inserting and fixing a temperature compensation connection port from one end, a space unit extended from the reception unit toward inside, and an optical fiber insertion hole penetrating a side surface of the other end along a center of an axial direction from an inclined surface gradually narrowed toward inside of the space unit; the temperature compensation connection port formed with a connection unit contacting with the reception unit of the ferrule, an optical fiber support unit having an outer diameter smaller than an inner diameter of the space unit of the ferrule from the connection unit and protruding to be spaced apart from an inlet of the ferrule by a predetermined distance to form a space for accommodating the Bragg grating and support an optical fiber, and the optical fiber insertion hole penetrating both ends along the center of the axial direction to insert the optical fiber; an optical fiber cable having the optical fiber inserted into the optical fiber insertion hole of the temperature compensation connection port and the optical fiber insertion hole of the ferrule and the Bragg grating placed in the space unit of the ferrule; and a socket, one end of which is fixed to the ferrule, and the other end of which is fixed to an optical fiber cladding of the optical fiber cable.

Thermal compensation composition of optical fiber connector containing a fiber Bragg grating

The present invention proposes a wavelength division multiplexing-passive optical network (WDM-PON) system which transmits downstream data to an optical network unit (ONU) as an optical line termination (OLT) receives seed light from a spectrum-sliced external light source module. One characteristic of the proposed WDM-PON system is that optical transmitters of the OLT and ONU are operated regardless of optical wavelength. Another characteristic of the proposed WDM-PON system is that a conventional TDMA-PON (E-PON or G-PON) ONU can be accommodated without a change.

Wavelength division multiplexing-passive optical network system

An optical backhaul network for a wireless broadband service is provided. The optical backhaul network for a wireless broadband service includes: a plurality of optical network units for outputting an uplink optical signal having a multiplexed wavelength; an optical line termination for outputting a downlink optical signal of a single mode in order to transmit the downlink optical signal to the plurality of the optical network units in a broadcasting form; and a plurality of remote nodes for outputting a part of the downlink optical signal to the plurality of the optical network units and for outputting the uplink optical signal to the optical line termination. Therefore, one center and a plurality of access points can be efficiently connected.

Optical backhaul network for wireless broadband service

Provided are a wavelength division multiplexing-passive optical network (WDM-PON) in which a reflective semiconductor optical amplifier (RSOA) is used as each optical transmitter of an optical line termination (OLT) and an optical network unit (ONU) and additional spectrum-sliced light is injected into RSOAs of each of the OLT and the ONU, and a WDM-PON that is combined with time division multiple access (TDMA) technology, by which the number of included ONUs increases and conventional TDMA ONUs can be used.

Wavelength division multiplexing-passive optical network using external seed light source

Provided is a time division multiple access over wavelength division multiplexed passive optical network (TDM-over-WDM-PON) system. According to the TDM-over-WDM-PON system, a downstream optical signal is separated according to a wavelength in a remote node, transmitted to an optical amplifying device located in subscriber equipment, amplified in the optical amplifying device, transmitted back to the remote node, and then transmitted to the subscriber equipment. Also, an upstream optical signal is transmitted to a wavelength converting device located in the subscriber equipment from the remote node, wavelength-converted in the wavelength converting device, returned back to the remote node, and then transmitted to a central office.

Time division multiple access over wavelength division multiplexed passive optical network

In a method of allocating a bandwidth of a passive optical network, downward data are transmitted by varying a wavelength based on a wavelength division method and upward data are transmitted using a time division method. Thereby, by efficiently allocating a network bandwidth, data can be transmitted and by realizing statistical multiplexing, transmission efficiency can be improved.

Method of allocating bandwidth of passive optical network

A Reflective Semiconductor Optical Amplifier (RSOA) for compensating for light loss in an optical link, an RSOA module for improving polarization dependency using the RSOA, and a Passive Optical Network (PON) for increasing economical efficiency and practical use of a bandwidth using the RSOA are provided. The PON includes a central office comprising a plurality of optic sources transmitting a downstream signal and a plurality of first receivers receiving an upstream signal; at least one optical network terminal (ONT) including a second receiver receiving the downstream signal and an RSOA which receives the downstream signal, remodulates the downstream signal into the upstream signal, and transmits the upstream signal in loopback mode; and a remote node interfacing the central office with the ONT. The upstream signal and the downstream signal are transmitted between the remote node and the ONT via a single optical fiber. The remote node includes an optical power splitter at its port connected to the ONT.

Reflective semiconductor optical amplifier (RSOA), RSOA module having the same, and passive optical network using the same

The present invention relates to an apparatus with reconfiguration function and signal gathering function. The apparatus with reconfiguration function and signal gathering function according to the present invention comprises a signal gathering unit which gathers at least one alarm digital alarm signal, an alarm signal address setting unit where the address of the alarm signal gathering unit is setup; and an alarm signal collection controller which outputs the at least one digital alarm signal through serial bus. Therefore, address is allocated to a plurality of digital signals and thus the number of necessary components decreases and the embodiment area decreases, as well.

Apparatus with reconfiguration function and signal gathering function

Provided are a fault localization apparatus based on an optical communication network and a method thereof. In the fault localization apparatus according to the present invention, a downstream light source is used as a monitoring optical signal instead of using an additional monitoring light source and a subcarrier multiplexing (SCM) monitoring pulse signal of a certain frequency band having no interference with a frequency band of a downstream data signal is used and thus a fault position may be detected at low cost.

Fault localization apparatus for optical line using subcarrier multiplexing (SCM) monitoring signal and method thereof

Provided are a wavelength conversion apparatus in a Time Division Multiplexing Passive Optical Network (TDM-PON) system based on a Wavelength Division Multiplexing (WDM) system, and an optical transmission method using the wavelength conversion apparatus. Each subscriber does not need to have its own wavelength but transmits an uplink signal using a wavelength band used in the TDM-PON system and routs optical network unit (ONU) uplink signals belonging to the same ONU to a wavelength conversion apparatus positioned in a subscriber area. The wavelength conversion apparatus converts the ONU uplink signals into wavelengths and uplinks the wavelengths of an optical line terminal (OLT) of a central office (CO) so as to enable a WDM transmission. Thus, a method of constituting a wavelength conversion apparatus and a remote node (RN) using the wavelength conversion apparatus can be suggested to realize a hybrid-PON system into which TDM-PON system and WDM systems are combined. In the hybrid-PON system, an ONU uses a wavelength used in the TDM-PON system and requires a lower optical power than an ONU of the TDM-PON system. Therefore, the WDM system can be easily applied in an area in which the TDM-PON system is installed.

Wavelength conversion apparatus in time division multiplexing&#x2014;passive optical network system based on wavelength division multiplexing system, and optical transmission apparatus and method using the same

Provided is an athermal external cavity laser (ECL), whose output optical power and output wavelength can be kept regular irrespective of temperature changes without using additional temperature controlling components. The ECL comprises: a semiconductor amplifier; an optical fiber comprising a core in which a Bragg grating is formed and a cladding surrounding the core; and a thermosetting polymer that fixes the optical fiber to a ferrule and has a negative thermooptical coefficient, wherein the thickness of the cladding surrounding the core in which the Bragg grating is formed is smaller than the portion of the cladding surrounding the portion of the core where the Bragg grating is not formed, and the thermosetting polymer the negative thermooptical coefficient surrounds the cladding. The ECL does not need additional temperature controlling components and thus can be manufactured compact and at low cost, and thus can be used as a light source of a dense wavelength division multiplexing (DWDM) system in designing economical WDM passive optical networks (PON).

Athermal external cavity laser

Provided are an apparatus and method for tracking a wavelength in a passive optical subscriber network in which a central base station and at least one subscriber terminal are connected via a remote node. The apparatus includes a first wavelength aligning unit multiplexing and aligning wavelengths of optical signals from a plurality of single-mode optical sources of the central base station; a second wavelength aligning unit multiplexing and aligning wavelengths of optical signals transmitted to the remote node from a plurality of single-mode optical sources of the subscriber terminal; and a third wavelength aligning unit demultiplexing and aligning wavelengths of optical signals from the second wavelength aligning unit, the third wavelength aligning unit being included in the central base station. Accordingly, when the wavelengths of passbands of a multiplexer/demultiplexer (MUX/DEMUX) of a remote station change due to a change in the ambient temperature, wavelength tracking is performed by making aligned the wavelengths of optical sources of a central base station, a multiplexer/demultiplexer, and subscriber terminals, thereby minimizing optical channel loss and enabling reliable management of WDM-PON.

Wavelength tracking apparatus and method in WDM-PON system

Provided are extendable loop-back passive optical network (PON) and scheduling method and apparatus for the same. The loop-back type PON includes an OLT (optical line terminal) including a wavelength-tunable optical transmitter and a wavelength-locked optical receiver, and an RN (remote node) including an optical coupler/splitter, the optical coupler/splitter receiving optical signals from the wavelength-tunable optical transmitter and splitting the optical signals by wavelength so as to transmit the optical signals to corresponding ONTs (optical network terminals). Each of the ONTs transmits upstream data to the OLT using the same wavelength as the wavelength of the optical signal received from the OLT through the RN. Since the optical network makes use of the TDM and WDM communication schemes, the optical network can be maintained and upgraded at lower cost.

Extendable loop-back type passive optical network and scheduling method and apparatus for the same

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Daejeon, South Korea

Byoung Whi Kim