• ETRI Journal
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• v.38 no.1
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• pp.9-17
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• 2016

We demonstrate a time- and wavelength-division multiplexed passive optical network system employing a vertical-cavity surface-emitting laser array-based optical line terminal transceiver and a tunable bidirectional optical subassembly-based optical network terminal transceiver. A packet error-free operation is achieved after a 40 km single-mode fiber bidirectional transmission. We also discuss an arrayed waveguide grating, a photo detector array based on complementary metal-oxide-semiconductor photonics technologies, and low-cost key devices for deployment in access networks.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.5
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• pp.64-71
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• 2009

Cylindrical lens core for optical transceiver was designed and machined. With the lens design data, WC asymmetric core surface data were generated for non-revolutional ultra-precision grinding. Grinding process for optimum machining conditions of target surface was studied in terms of surface roughness and form profile. We used experimental results to optimize turbine speed, feed-rate and depth of cut with durable grinding wheel wear. Ground WC cores were measured contact type profilers and verified.

• Journal of Sensor Science and Technology
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• v.24 no.4
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• pp.232-238
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• 2015

In this paper, we introduce a passive transponder in which an LED is used for both a light transmitter and a receiver, and a solar cell is used for supplying power to the all devices in the transponder. The LED in the transponder operates as a photodetector in the receiving mode, and acts as a light source in the transmitting mode. The current responsivity of the LED detector was measured to be in the order of $10^{-4}A/W$, and the receiving bandwidth with a load resistance of $10k{\Omega}$ was about 10 to 30 kHz. Using the LED for an optical transceiver in a VLID transponder, the detection range was about 70 cm when the transponder was illuminated by the visible light from a $3{\times}3$ LED array in a reader.

• Journal of Satellite, Information and Communications
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• v.8 no.1
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• pp.71-76
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• 2013

In this paper, a transceiver of VLC (Visible Light Communication) using LED white lighting has been implemented. The transmitted waveforms of LED and PD (Photo Diode) of the received signal are analyze to restore VLC data. Audio signal was successfully transmitted to demonstrate possibility and potential of optical wireless communication systems. Various modulation formats are considered to evaluate and compare performance in diverse channel conditions.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.346-348
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• 2003

본 논문에서는 플라스틱 광섬유용(POF) 광커넥터와 광송수신모듈을 설계. 제작하여 특성을 평가하였다. 650nm와 850nm POF 광커넥터는 광학적, 기계적, 환경적 신뢰성 시험을 통해 안정성을 확증할 수 있었다. POF 광송수신모듈은 1.25Gbps와 155Mbps급의 SC, RJ-45 형태의 구조로 제작되었고, 이를 적용하여 S/W Hub 및 광전 Outlet, Media Converter등을 구현하였다.

• Electronics and Telecommunications Trends
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• v.37 no.2
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• pp.42-52
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• 2022

Intra- and inter- datacenter data traffic is rapidly increasing due to the spread of smart devices, cloud computing, and non-face-to-face services. Recently, 400-Gbps optical transceivers based on 100-Gbps/channel have been released primarily by major overseas companies. Various solutions for next-generation datacenter interconnect are being proposed by international standardization and multiple source agreement groups. Following this trend, ETRI has developed a 400-Gbps optical transmission/reception engine using 100-Gbps/channel light sources and photodetectors as well as a silica-based AWG. In the future, technologies of optical devices and components for intra-datacenter communication are expected to be developed based on a data rate of 200-Gbps/channel. Thus, 1.6-Tbps class optical transceivers will be released.

• Electronics and Telecommunications Trends
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• v.37 no.3
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• pp.11-22
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• 2022

The development and application of silicon photonics technology to terabit optical transmission are expected in the future. Silicon photonics technology is recognized as the only technology focusing on increasing the bandwidth of data center switches. High-density integration-based small optical subassemblies, optical engines, and optical transceivers are converged with the silicon photonics technology to accelerate a revolution in optical interfaces.

• Korean Journal of Optics and Photonics
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• v.24 no.1
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• pp.23-28
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• 2013

In this paper, an optical system was designed for 3D imaging laser radar with optical scanner. In order to make it easy to scan, the system was designed to inscribe the transmitting objective lens in the receiving lens. In transmitting optics, the beam expander was designed to have a zoom mechanism so that the transmitted beam size would be 4.8 m or 6.8 m at 1 km distance, when the laser source's numerical aperture value is between 0.13 and 0.22. The beam diameter at the target 1 km away was confirmed by design program. The receiving optics for the returning beam from the target was designed for the $16{\times}16$ array detector with $100{\mu}m$ pixel width. The spot diameter in every pixel was designed and verified to be less than $55{\mu}m$. The receiving optics' obscuration ratio by transmitting optics was 11%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1263-1269
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• 2012

This paper is the research on the heated CWDM optical transmitter for the wavelength compensation at the low temperature. In general, the wavelength deviation of DFB laser is around 0.1 nm/C. The wavelength of DFB laser shifts to longer(shorter) wavelength according to the temperature increase(decrease). Typical CWDM optical communication network has 20 nm channel spacing from reference center wavelength per each channel. There is some limitation problem in the range of operating temperature due to the channel interference. For solving the limited temperature range problem, especially at the low temperature, we use the heater on the DFB laser. As a result, we could realize the CWDM optical transmitter to meet +/-6.5 nm from reference center wavelength in the range of temperature at $-40{\sim}+85^{\circ}C$, which is applicable to the industrial field.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7A
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• pp.535-541
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• 2005

This paper proposes a hybrid optical lines composed of single-mode fiber(SMF) and multi-mode fiber(MMF) for gigabit-capable Passive Optical Network(GPON) using a WDM method with a single light source per each channel, and reports the results of transmission performance the proposed lines. The transmission link uses a direct modulated DFB-LD for high speed downstreams at the optical line terminal(OLT) of central office(CO) and a low cost SFP type transceiver for low-speed upstream in optical network unit(ONU). To split or combine the transmission channels, wavelength MUX/DEMUX are used in the optical line section, and MMFs not longer than 1 km are attached to the SMF lines at the ONU side of the WDM-PON links. We have performed the transmission experiment on the downstream of 2.5 Gbit/s, and 1.25 Gbit/s, and the upstream of 1.25 Gbit/s, and 622 Mbit/s which are recommended by ITU-T G.984.2. The transmission margin and feasibility of the proposed links have been tested to be suitable up to 2.5 Gbit/s transmission.