Electronics and Telecommunications Research Institute

Heuk Park

Hwan Seok Chung

Joon Ki Lee

Won Kyoung Lee

Sanghwa Yoo

Kwang Joon Kim

Hyun Jae Lee

Sang Soo Lee

Jyung Chan Lee

Soon-Seok Lee

Sae Kyoung Kang

Sang-Soo Lee

Seung-Hyun Cho

Hee Sang Chung

Sang-Kyu Lim

Hyunwoo Cho

Han Hyub Lee

Sae-Kyoung Kang

Joon Young Huh

Bong Kyu Kim

Sun Hyok Chang

Lee-Mi Do

Jie Hyun Lee

Je-Soo Ko

Jin Soo Han

Jongtae Song

Jang-Joo Kim

Hye-Yong Chu

Tae-Hyoung Zyung

Jong-Tae Song

Sang Jo Park

Sooyeon Kim

Kyung-Gyu Jeon

Seong-Hyun Kim

Do-Hoon Hwang

Jeong-Ik Lee

Ji Sung Jung

According one embodiment of the present disclosure, there is provided a silicon photonics-based optical modulation device having two metal layers. The optical modulation device includes a phase shifter, a ground unit, and a pad unit. The phase shifter includes a first signal electrode, a second signal electrode, and at least two ground electrodes formed in a first metal layer. The phase shifter includes two silicon optical waveguides. The ground unit is formed in a second metal layer different from the first metal layer. The pad unit is formed in the second metal layer, provided with a first local area electrically connected to the ground unit, and electrically connected to the first signal electrode and the second signal electrode via a second local area thereof electrically isolated from the ground unit.

Silicon photonics-based optical modulation device with two metal layers

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

Disclosed are a terahertz signal generation apparatus and a terahertz signal generation method using the same. The terahertz signal generation apparatus includes first and second resonators configured to respectively output an optical signal of a first resonant frequency and an optical signal of a second resonant frequency from an optical signal input through a gain medium, an optical modulator configured to optically modulate the output optical signal of the second resonant frequency, an optical combiner configured to combine the CW optical signal of the first resonant frequency and the modulated optical signal of the second resonant frequency, and a signal generator configured to generate a terahertz signal using heterodyne beating between the CW optical signal of the first resonant frequency and the modulated optical signal of the second resonant frequency, wherein the first resonant frequency and the second resonant frequency are processed to have a predetermined frequency difference.

Terahertz signal generation apparatus and terahertz signal generation method using the same

Disclosed is a silicon photonics-based optical transmission apparatus. The apparatus includes an optical modulator chip of a ground-signal-ground (GSG) electrode array including two phase shifters for differential driving, a sub-substrate including a metal electrode of a periodic pattern to connect two ground metal electrodes to each other at a GSG electrode connected to each of the two phase shifters, and a solder bump having a same periodic pattern as the metal electrode of the sub-substrate to connect the ground metal electrodes of the optical modulator chip and the metal electrode of the periodic pattern of the sub-substrate.

Silicon photonics-based optical transmission apparatus

An optical coupling method and apparatus are disclosed. The optical coupling method improve the speed of optical alignment between an optical fiber and a grating coupler (GC) of an optical coupling apparatus for a characteristic test of a silicon photonic integrated circuit (Si-PIC) chip by using a reflective grating couplers disposed on the Si-PIC chip.

Optical coupling method and apparatus

Wavelength channels used in the optical network system are classified into downstream channels used to transmit optical signals from an optical line terminal (OLT) to an optical network unit (ONU) and upstream channels that are used to transmit optical signals from the ONU to the OLT. The wavelength channels are included in an O-band and may not overlap each other. One of the upstream channels are allocated to a wavelength band (for example, a zero-dispersion window) in which a four-wave mixing occurs. A wavelength spacing between the upstream channels and the downstream channels is determined based on a performance of separating the upstream channels and the downstream channels in a bidirectional optical sub assembly (BOSA) of the ONU. Also, a wavelength spacing between the downstream channels is determined based on a performance of separating the downstream channels in the BOSA.

Optical network system using wavelength channels included in O-band

A bidirectional optical element in optical network units (ONUs) of a passive optical network (PON) includes a main filter configured to pass an upstream signal having an upstream-channel wavelength and a downstream signal having a downstream-channel wavelength, a drop filter configured to pass the downstream signal having the downstream-channel wavelength and reject the upstream signal having the upstream-channel wavelength, and an add filter configured to pass the upstream signal having the upstream-channel wavelength and reject the downstream signal having the downstream-channel wavelength, wherein the main filter, the drop filter, and the add filter are configured to share a single optical waveguide, and the optical waveguide is configured to connect input ports of the main filter and the drop filter and an output port of the drop filter and is provided in a straight line shape.

Bidirectional optical element

A flexible printed circuit board (FPCB) for an optical module includes: a signal via pad connected with a signal lead pin of the optical module; a ground layer spaced apart from the signal via pad; an isolation gap formed between the signal via pad and the ground layer; and a protective layer which is formed at a portion that comprises the isolation gap, and which, when connected with the signal via pad, compensates for parasitic inductance caused by a protruding signal lead pin.

Flexible printed circuit board for optical module

Provided is a phase error compensating apparatus. The phase error compensating apparatus may include a waveguide array disposed between a first free propagation region and a second free propagation region and configured to allow a light signal passed through the first free propagation region to move toward the second free propagation region, in which a length of each of the waveguides included in the waveguide array may be adjusted to compensate for a phase error of light signals passed through the waveguides.

Phase error compensating apparatus

An arrayed waveguide grating device and a method for manufacturing the arrayed waveguide grating device. The arrayed waveguide grating device includes input channel waveguides formed on a substrate; output channel waveguides formed on the substrate that correspond to the input channel waveguides; and arrayed waveguides with different lengths interposed between the input channel waveguides and the output channel waveguides on the substrate while free propagation regions being formed at both ends of the arrayed waveguides, wherein the arrayed waveguides are designed so that a free spectral range (FSR) of a higher-order mode is twice or greater than a bandwidth of a region of interest (ROI).

Arrayed waveguide grating device and method for 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

Provided are a method and apparatus for blocking forged multicast packets. The apparatus includes input and output ports connected to user terminals; a forwarding process unit transferring a frame input through one of the input ports to one of the output ports connected to a user terminal having a destination address; a determination unit determining an address of a user terminal connected to one of the input ports from a source address included in the frame; a filtering database storing information on the output port connected to the user terminal having the destination address of the frame based on information received from the determination unit; a multicast gate information unit including information on multicast media access control (MAC) addresses of frames providing a monodirectional multicast service and blocking or forwarding all frames having a corresponding multicast MAC address as the destination address by checking whether the input and output ports are connected to an Internet group management protocol (IGMP) querier or not; and a port information transference unit learning the multicast MAC address of the IGMP querier connected to the apparatus, obtaining information on a port having the multicast MAC address as the destination address from the filtering database, and transferring the information to the multicast gate information unit. According to the present application, forged traffic is blocked from being multicasted and thus restricted resources of a network are prevented from being wasted. As a result, the network may be used more efficiently in an industrial field.

Method and apparatus for blocking forged multicast packets

Provided are an apparatus and method for providing an advertisement service personalized for each user or for each group. The personalized advertisement providing method includes: a personalized advertisement providing method which is used in an Internet Protocol Television (IPTV) System, including: receiving at least one broadcasting program of a plurality of broadcasting programs classified according to a plurality of channels; and determining whether a present time is an advertisement broadcasting time, transmitting a received broadcasting program to a plurality of user terminals which selects a channel on which the broadcasting program is provided if the present time is not an advertisement broadcasting time, dividing the plurality of user terminals into a plurality of groups and transmitting an advertisement classified for each group to one or more user terminals belonging to the group if the present time is an advertisement broadcasting time. Therefore, it is possible to enhance use efficiency of bandwidths, to reduce restrictions related to installation, etc. of an apparatus for providing advertisement services, and to reduce the number of apparatuses that have to be installed, resulting in reduction of costs.

Method and apparatus for providing personalized advertisements in internet protocol TV (IPTV) system

Provided are an acousto-optic filter and an optical code division multiple access (CDMA) system using the acousto-optic filter. The acousto-optic filer includes: an acousto-optic mode converter (AOMC) converting an optical signal of a specific optical frequency corresponding to a frequency of an electric signal of an optical signal of a first mode having a predetermined optical frequency band; and a mode stripper (MS) stripping an optical signal of the optical signal of the first mode that has been converted to a second mode.

Acousto-optic filter and optical CDMA system using the same

Provided are an apparatus and a method for reducing a signal noise of an OCDMA receiver and an OCDMA receiver and method. The includes: a clock recovery unit extracting sine wave clock from an output signal of an OCDMA decoder including an MAI (multiple access interference) noise; a time gating unit separating an auto-correlation peak signal and the MAI noise from the output signal of the OCDMA decoder using the sine wave clock; and an optical interferometer removing an SI (signal interference) noise remaining in the auto-correlation peak signal.

Growing community of inventors

Daejeon, South Korea

Heuk Park