Electronics and Telecommunications Research Institute

Korea Telecom

Duk Jun Kim

Joong-Seon Choe

Jong-Hoi Kim

Chun Ju Youn

Eun Soo Nam

Yong-Hwan Kwon

Gyungock Kim

Jang Uk Shin

Won Seok Han

Junghyung Pyo

Sang Seok Lee

Sang Ho Park

Yongsoon Baek

Kwang-Seong Choi

Jong Moo Lee

Yark Yeon Kim

Dong-Young Kim

Tae Goo Choy

Young Tak Han

Jin Woo Hahn

Gee Pyeong Han

Yoon Jung Park

Hyun Soo Kim

Jeong Woo Park

Young-Tak Han

Ki Seok Jang

In Gyoo Kim

Sang Gi Kim

Byung-Seok Choi

Sanghoon Kim

Sahnggi Park

Jonghyurk Park

Jung-Ho Song

Dongwoo Suh

JiHo Joo

Do Won Kim

Hee Kyung Sung

Young-Ho Ko

Kap-Joong Kim

Dae Seo Park

Jongbum You

Dong Hyo Lee

Ho Sung Kim

Hee Keyng Sung

An optical alignment device according to an embodiment of the inventive concept includes an optical alignment plate having a first hole and at least one second hole, in which the first hole and the second hole pass through the optical alignment plate, and an optical detection element disposed on the optical alignment plate. Here, the optical detection element includes a substrate having a first surface and a second surface, which face each other, a lens disposed on the first surface, and an optical sensor disposed on the second surface, and the optical detection element vertically overlaps the first hole and the second hole. The lens is exposed to the outside by the first hole, and the second hole is connected with a vacuum suction unit to fix the optical detection element to the optical alignment plate.

Optical alignment device

Disclosed are a Mach-Zehnder interferometric optical modulator and a method for manufacturing the same. The modulator includes first and second lower clad layers, a core layer, an upper clad layer, a waveguide, and electrodes. The waveguide may include an input waveguide, a waveguide divider, branch waveguides, and a waveguide combiner. Each of the branch waveguides includes first and second connection regions connected to the waveguide combiner and the waveguide divider, respectively, and a phase shift region having a cross-section of a reverse mesa structure that has an upper width that is the same as widths of the first and second connection regions and a lower width that is smaller than the widths of the first and second connection regions.

Mach-zehnder interferometric optical modulator with shallow ridge waveguide structure and method for manufacturing the same

Provided is a waveguide photodetector including a semiconductor substrate, a first optical waveguide and a second optical waveguide, which are sequentially laminated on the semiconductor substrate, in which each of the first optical waveguide and the second optical waveguide includes a first portion and a second portion, and the first portion extends from the second portion in a first direction parallel to a top surface of the semiconductor substrate, a refractive index matching layer disposed on the second portion of the second optical waveguide, a clad layer disposed on the refractive index matching layer, and an absorber disposed between the refractive index matching layer and the clad layer. Here, the second optical waveguide has a first conductive-type, the clad layer has a second conductive-type opposite to the first conductive-type, and the refractive index matching layer includes a first semiconductor layer that is an intrinsic semiconductor layer.

Waveguide photodetector

An optical waveguide structure includes a substrate and a core structure disposed on the substrate. The substrate includes a first waveguide region, a second waveguide region, and a transition region between the first waveguide region and the second waveguide region. The core structure includes first core segments arranged in a first direction and a second direction crossing the first direction on the transition region. The core structure includes second core segments arranged in the first direction and the second direction on the second waveguide region. The first direction and the second direction are parallel to a top surface of the substrate.

Optical waveguide structure

Disclosed are a method and an apparatus for transmitting and receiving coherent optical OFDM. The apparatus includes: a transmitted OFDM digital signal processing unit outputting an in-phase (I) component digital signal and a quadrature phase (Q) component digital signal; a digital-analog converter converting the in-phase (I)-component digital signal and the quadrature-phase (Q)-component digital signal into an in-phase (I)-component analog signal and a quadrature-phase (Q)-component analog signal, respectively; an adder adding an additional pilot tone signal to each of the in-phase (I)-component analog signal and the quadrature-phase (Q)-component analog signal outputted from the digital-analog converter; and an optical I/Q modulator up-converting the in-phase (I)-component analog signal added with the additional pilot tone signal and the quadrature-phase (Q)-component analog signal added with the additional pilot tone signal to an optical domain to output a coherent optical OFDM signal including the additional pilot tone signal.

Method and apparatus for transmitting and receiving coherent optical OFDM

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.

Apparatus and method for measuring IQ imbalance for optical receiver

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.

Measuring device and method of measuring signal transmission time difference thereof

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.

Apparatus for measuring performance of coherent optical receiver

Provided is an electro-optic modulating device. The electro-optic modulating device includes an optical waveguide with a vertical structure and sidewalls of the vertical structure are used to configure a junction.

Electro-optic modulating device

Provided is a silicon array waveguide grating (AWG) device comprising a silicon array waveguide in which a plurality of optical waveguides formed of a lower cladding layer, a silicon core, and an upper cladding layer are arranged, wherein the variation of the refractive index of the silicon core is positive, and the upper cladding layer is formed of polymer, the variation of refractive index of which according to temperature is negative, which is opposite to the silicon core, and the cross-section of the silicon core varies between different areas to adjust the variation of the effective refractive index of the optical waveguide according to temperature.

Silicon arrayed waveguide grating device for reducing effective refractive index variation of optical waveguide according to temperature

An optical filter module for wavelength multiplexing and demultiplexing and a method of manufacturing the same are provided. The optical filter module for wavelength multiplexing and demultiplexing includes: at least one or more input waveguides; an input-stage star coupler in the form of a slab waveguide connected to the input waveguides; array waveguide which is connected to the input-stage star coupler and in which a plurality of individual waveguides, each of which has an optical path having a predetermined length different to those of the other waveguides and has a heterogeneous waveguide interval formed of a material having a different refraction index from that of a core of the waveguides, are sequentially arranged; an output-stage star coupler in the form of a slab waveguide connected to the array waveguides; and at least one or more output waveguides connected to the output-stage star coupler. According to the optical filter module and the method of manufacturing the same, heterogeneous waveguide intervals having core materials different from those of conventional waveguides are introduced in predetermined areas of array waveguides, thereby reducing polarized light and temperature dependency and at the same time effectively removing optical coupling loss, which can occur at both ends of a heterogeneous waveguide interval, without an additional process of forming waveguides.

Optical filter module and method of manufacturing the same

Provided are a multi-wavelength optical transceiver module and a multiplexer/demultiplexer using a thin film filter. The multi-wavelength optical transceiver module includes: a PLC platform, on which a predetermined optical waveguide unit is formed and an optical transmitter is mounted; an optical fiber coupled to one side of the PLC platform to transmit a predetermined light; a plurality of thin film filters coupled to another side of the PLC platform to separate input optical wavelengths; and an optical receiver coupled to one side of the thin film filters to receive light that is input from the optical fiber and transmits the thin film filters, thereby enabling mass production of the optical transceiver module with low cost.

Multi-wavelength optical transceiver module, and multiplexer/demultiplexer using thin film filter

An optical waveguide platform and a method of manufacturing the same are disclosed. The optical waveguide platform comprises an optical waveguide having a lower clad layer, a patterned core layer and an upper clad layer which are laminated on one area of said substrate sequentially, a terrace formed by patterning said lower clad layer, on the other area of said substrate, a metal and a solder formed on said terrace and an optical device mounted on said terrace containing said metal and said solder. According to the present invention, the optical waveguide platform can be manufactured in a simple method without damaging the optical waveguide and the manufacturing cost thereof can be reduced.

Optical waveguide platform and method of manufacturing the same

A dielectric ceramic composition for a microwave device including MgTiO.sub.3 and CaTiO.sub.3 as a main component and a Li.sub.2 CO.sub.3 as a sub-component is provided. The composition being expressed as follows: (94MgTiO.sub.3 -6CaTiO.sub.3)+xLi.sub.2 CO.sub.3 (mol %), where 0.2.ltoreq.x.ltoreq.0.8 (mol %). Therefore, it is capable of increasing a quality factor and decreasing a sintering temperature by adding a new component and effectively reproducing the above-described dielectric characteristic.

Dielectric ceramic composition of microwave MGTIO.sub.3 CATIO.sub.3

A microwave dielectric ceramic composition is fabricated by adding one selected from a material containing Ba and a material containing Sr or a mixture of a material containing Ba and a material containing Sr to a composition formed of 25.about.43 wt % of TiO.sub.2, 39-57 wt % of ZrO.sub.2, and 7-28 wt % of SnO.sub.2 as an additive, wherein the additive is added by 0.2.about.8.0 wt % based on the total amount of the composition, and is capable of implementing a high dielectric constant and quality factor by sintering at a temperature of 1250.about.1400.degree. C.

Microwave dielectric ceramic composition

Growing community of inventors

Daejeon, South Korea

Duk Jun Kim