Electronics and Telecommunications Research Institute

Jyung Chan Lee

Joon Ki Lee

Kwang Joon Kim

Kwangjoon Kim

Seung Il Myong

Sang Soo Lee

Moo Jung Chu

Min Soo Kim

Je Soo Ko

Heuk Park

Sae Kyoung Kang

Yun Hee Cho

Eun Gu Lee

Sil Gu Mun

Hyun Woo Lee

Hyun Jae Lee

Jong Hyun Lee

Hee Sang Chung

Joon Young Huh

Jie Hyun Lee

Sanghwa Yoo

Eun-Gu Lee

Youn Seon Jang

Sang Kyu Lim

Sooyeon Kim

Seon Mo Kang

Seung Ii Myoung

Seoung Il Myong

Jun Ki Lee

Provided are an optical transceiver and a method of optimizing the optical transceiver. The method of optimizing the optical transceiver includes performing power control of communication elements included in a transmitter and a receiver included in the optical transceiver based on a signal flow of the transmitter and the receiver, performing performance initialization of the communication elements based on a control range for each detailed function of the communication elements, and performing performance optimization of the communication elements based on change characteristics of a bit error rate (BER) for each detailed function of the communication elements.

Optical transceiver and method of optimizing optical transceiver

A silicon photonics-based optical modulator is disclosed. The optical modulator includes first radio frequency (RF) metal electrodes that operate as a ground, phase shifters disposed between the first RF metal electrodes for optically modulating an optical signal transmitted along an optical waveguide, second RF metal electrodes disposed between the phase shifters for providing an RF electrical signal received from a driving driver located outside of the optical modulator through one end, resistor-inductors (RL) connected to another end of the second RF metal electrodes, an inductive line disposed between the RLs and a power supply for applying a bias voltage to the optical modulator and the driving driver, and a silicon capacitor disposed between the RLs and the power supply for preventing a degradation of an RF response characteristic of the silicon photonics-based optical modulator caused by the inductive line.

Silicon photonics-based optical modulator

A method and apparatus for generating a four-level pulse amplitude modulation (PAM-4) optical signal are disclosed. The method of generating a PAM-4 optical signal may include outputting a PAM-4 electrical signal, generating a PAM-4 optical signal based on the PAM-4 electrical signal, extracting feature information of the PAM-4 electrical signal from the PAM-4 electrical signal, and generating a control signal to control an operation of generating the PAM-4 electrical signal based on the feature information.

Apparatus and method for generating PAM-4 optical signal

An optical transceiver may include an optical receptacle configured to input or output an optical signal, a first planar lightwave circuit through which the optical signal travels, an arrayed waveguide grating connected to the first planar lightwave circuit, and a first spot size converter connecting the optical receptacle and the first planar lightwave circuit.

Optical transceiver based on planar lightwave circuit

Disclosed are an impedance correcting method and apparatus, and an impedance-corrected signal line for an optical transceiver. The impedance correction method includes receiving an impedance according to an error of a resin applying process of a signal line for an optical transceiver, acquiring a correction parameter for generating a correction impedance based on the impedance according to the error, and determining the correction impedance for correcting the impedance according to the error based on the correction parameter.

Impedance correcting method and apparatus, and impedance-corrected signal line for optical transceiver

An optical transceiver of a flexible modulation format. The optical transceiver may include an optical transmitter to convert an electrical signal to an optical signal and transmit the optical signal, an optical receiver to receive and convert the optical signal to an electrical signal, and a controller to set modulation formats of the optical transmitter and the optical receivers according to modulation format information.

Optical transceiver of flexible modulation format

An interface for transmitting a high-speed signal and an optical module including the same. The interface may include a main substrate and a sub-substrate. The main substrate may have at least one high-speed signal line formed on the upper surface of the main substrate. The sub-substrate may have a first conductive line formed on the lower surface thereof so as to adjust high-speed signal transmission characteristics of the high-speed signal line, wherein the first conductive line may be coupled to the upper surface of the main substrate and partially overlap with the high-speed signal line.

Interface for transmitting high-speed signal and optical module including the same

A board assembly for transmitting a high-speed signal and a method of manufacturing the same. The board assembly may include a submount board, a base board, and a contact member for a signal line. The submount board may include at least one first high-speed signal line formed on the surface thereof. The base board may include the submount board on one part of the upper surface thereof, and at least second high-speed signal line on the other part of the upper surface thereof, wherein the second high-speed signal lines corresponds to the first high-speed signal lines, respectively. The contact member for the signal line may be installed on the side of the submount board, and have an upper portion contacting the first high-speed signal line and a lower portion contacting the second high-speed signal line such that the first high-speed signal line contacts the second high-speed signal line.

Board assembly for transmitting high-speed signal and method of manufacturing the same

A tunable optical network unit (ONU) for a multi-wavelength passive optical network (MW PON) system and an operation method thereof are provided. The tunable ONU includes a cyclic tunable filter configured to have cyclic wavelength transmission properties that allow all wavelength channels of both a downstream signal and an upstream signal and to vary a wavelength to pass therethrough; a wavelength splitter configured to split an upstream signal wavelength band and a downstream signal wavelength band; a photodetector element configured to detect a downstream signal that is transmitted through the wavelength splitter, passing through the cyclic tunable filter which is aligned to a specific downstream signal wavelength channel; and a tunable transmitter configured to output to the wavelength transmitter an upstream signal of a wavelength channel that is determined based on an aligned downstream signal wavelength channel of the cyclic tunable filter.

Tunable optical network unit for multi-wavelength passive optical network system and operating method thereof

An active alignment method for a multi-channel optical transmitter and receiver is disclosed. The active alignment method for a multi-channel optical transmitter includes actively aligning an optical signal generator with an optical multiplexer based on optical outputs of a plurality of wavelengths from the optical signal generator and an optical output of the optical multiplexer, and actively aligning the optical multiplexer with a fiber optic coupler based on an optical output of the optical multiplexer and an optical output of the fiber optic coupler.

Active alignment method for multi-channel optical transmitter and receiver, which has an optical signal generator with an optical multiplexer, which has an optical signal generator with an optical multiplexer

An optical transceiver which can effectively reduce optical output jitter when an error is made during designing and manufacturing of a printed circuit board (PCB), and a method of controlling optical output jitter using the optical transceiver are provided. The optical transceiver includes a transmitter unit including an equalizing (EQ) filter which can reduce jitter of a high speed electric signal; a control circuit which controls the EQ filter; a receiver unit which receives an optical signal; and a micro-controller which controls the transmitter unit and the receiver unit. Further included in the optical transceiver is an active type or passive type EQ filter and, in the case of the active type, the control circuit is used to control the filter, in order to compensate for high-frequency component of a high speed electric signal in the transmitter unit in order to reduce reflection or loss on the PCB, and thus deterministic optical output jitter occurring due to Inter-Symbol Interference (ISI) can be reduced.

Optical transceiver and method of controlling optical output jitter using the same

A method and apparatus for controlling a wavelength tuning of an optical source in an optical communication system. An operating temperature of an optical source is controlled and monitored to shorten a wavelength tuning time of the optical source generated in an optical source generator. When the current operating temperature reaches a final target temperature, an operating current is supplied to the optical source generator, and transmission of the operating current to the optical source generator is controlled and monitored. When the operating current reaches a final operating current, the wavelength tuning of the optical source is terminated. The operating temperature is adjusted by distinguishing between a smaller amount of temperature change and a larger amount of temperature change to prevent oscillation at the point of reaching the final target temperature, thereby minimizing the time taken for the output wavelength tuning.

Method and apparatus for controlling wavelength tuning of optical source for optical communication

Provided are an apparatus and method for maintaining an constant extinction ratio of a laser diode (LD). The apparatus includes: an automatic power control circuit maintaining the constant optical power of the LD; a correlation deriver deriving correlations between a bias current of the LD and a modulation current to maintain the constant extinction ratio of the LD; and a modulation current control circuit controlling the modulation current to maintain constant the extinction ratio of the LD based on the correlations. The apparatus and method do not use a temperature sensor but derive a relationship between variances of a bias current of the LD and a modulation current according to temperature change, control the modulation current based on the relationship, and maintain the constant extinction ratio of the LD.

Apparatus and method for maintaining constant extinction ratio of laser diode

Provided is an optical transponder that receives a tributary signal such as a SDH/SONET signal, a GbE (Gigibit Ethernet) signal, and a SAN (Storage Area Network) signal in a WDM (Wavelength Division Multiplexing) transmission system and a SDH (Synchronous Digital Hierarchy)/SONET (Synchronous Optical Network) system, and more particularly, to an optical transponder having a switching function. The optical transponder having a switching function includes: a switch changing a data path of an input tributary signal from a plurality of channels (ports); an STM-64/OC-192 mapper/demapper mapping the tributary signal switched to a different data path by the switch to an STM-64/OC-192 signal or demapping the STM-64/OC-192 signal to the tributary signal; and a transmission delay time compensator compensating for a differential delay caused by a transmission route difference on an optical fiber link when the STM-64/OC-192 signal is demapped to the tributary signal.

Optical transponder having switching function

Provided are an optical transponder that processes a G.709 frame that includes an overhead for operation, administration, and maintenance of an optical channel and an overhead for forward error correction, and a method of detecting and treating errors in optical-channel sublayers of the same. The method includes detecting an error signal or a maintenance signal from a G.709 frame that includes an overhead for operation, administration, and maintenance of an optical channel and an overhead for forward error correction; treating errors in a predetermined layer of a plurality of layers that requires error treatment when the error signal or the maintenance signal is detected or canceled; and investigating a reason for the errors in the predetermined layer.

Growing community of inventors

Daejeon, South Korea

Jyung Chan Lee