• 한국광학회지
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• 제13권1호
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• pp.84-87
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• 2002

SOA (Semiconductor Optical Amplifier)의 inverter 원리를 응용하여 RZ 형식의 전광 XOR논리소자가 5 Gb/s 속도에서 처음으론 구현되었다. 먼저 Boolean AB와 Boolean AB가 실험적으로 구현되었으며 전광 XOR논리소자를 만들기 위해서 AB와 AB를 합하여 XOR의 Boolean 값인 AB+AB의 특성이 얻어졌다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2198-2200
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• 2000

This paper reports on the measurement of angle between micro mirror and substrate in. the Micro Optical Cross Connect(MOXC). MOXC consists of beam collimators and $N{\times}N$ micro mirrors that are fabricated by using MEMS technology. Using subpixel level image processing, it is possible to measure the angle with the resolution of 0.27$^{\circ}$.

• ETRI Journal
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• 제39권5호
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• pp.632-642
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• 2017

Digital all-optical parallel computing is an important research direction and spans conventional devices and convergent nano-optics deployments. Optical bus-based interconnects provide interesting aspects such as relative information communication speed-up or slow-down between optical signals. This aspect is harnessed in the newly proposed All-Optical Linear Array with a Reconfigurable Pipelined Bus System (OLARPBS) model. However, the physical realization of such communication interconnects needs to be considered. This paper considers spatial layouts of processing elements along with the optical bus light paths that are necessary to realize the corresponding interconnection requirements. A metric in terms of the degree of required physical constraint is developed to characterize the variety of possible solutions. Simple algorithms that determine spatial layouts are given. It is shown that certain communication interconnection structures have associated intrinsic topologies.

• ETRI Journal
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• 제25권3호
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• pp.149-155
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• 2003

A self-pulsating multisection distributed-feedback laser diode (DFB LD) can potentially realize all-optical clock extraction. This device generally consists of three sections, two DFB sections and one waveguide section. The most important variable in this device is detuning, which is the relative spectral position between the stop bands of two DFB sections. We fabricated a novel structure in which two gratings were located one over and one under the active layers. Each grating structure was independently defined in processing so that detuning, which is the prerequisite for self-pulsation, could be easily controlled. Observing various self-pulsating phenomena in these devices under several detuning conditions, we characterized the phenomena as dispersive Q-switching, mode beating, and self-mode-locking.

• 한국정밀공학회지
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• 제16권9호
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• pp.149-158
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• 1999

The modern trends of optical storage devices can be characterized by high density in information recording, and high bandwidth in data input/output processing rate. These make servo engineers to face with a new barrier on control system design in much more difficult way. The first step to attack this barrier will be through a systematic modeling for the dynamic characteristics of optical storage drive. in this paper, an analytical dynamic model for an optical storage drive based on FEM is drived, and compared with experimental results. Through this comparison, a practical dynamic model on the focusing and tracking motion of optical storage drive is proposed for the initiation of real control system design problem.

• 진공이야기
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• 제4권3호
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• pp.16-20
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• 2017

Graphene has emerged as a promising material for optoelectronic applications including as ultrafast and broadband photodetector, optical modulator, and nonlinear photonic devices. Graphene based devices have shown the feasibility of ultrafast signal processing for required for photonic integrated circuits. However, on-chip monolithic nanoscale light source has remained challenges. Graphene's high current density, thermal stability, low heat capacity and non-equilibrium of electron and lattice temperature properties suggest that graphene as promising thermal light source. Early efforts showed infrared thermal radiation from substrate supported graphene device, with temperature limited due to significant cooling to substrate. The recent demonstration of bright visible light emission from suspended graphene achieve temperature up to ~3000 K and increase efficiency by reducing the heat dissipation and electron scattering. The world's thinnest graphene light source provides a promising path for on-chip light source for optical communication and next-generation display module.

• Journal of Information Processing Systems
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• 제19권3호
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• pp.394-406
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• 2023

In this study, a real-time surveillance system using Internet of Things technology is proposed for vaccine cold chains. This system fully visualizes vaccine transport and storage. It comprises a 4G gateway module, lowpower and low-cost wireless temperature and humidity collection module (WTHCM), cloud service software platform, and phone app. The WTHCM is installed in freezers or truck-mounted cold chain cabinets to collect the temperature and humidity information of the vaccine storage environment. It then transmits the collected data to a gateway module in the radiofrequency_physical layer (RF_PHY). The RF_PHY is an interface for calling the bottom 2.4-GHz transceiver, which can realize a more flexible communication mode. The gateway module can simultaneously receive data from multiple acquisition terminals, process the received data depending on the protocol, and transmit the collated data to the cloud server platform via 4G or Wi-Fi. The cloud server platform primarily provides data storage, chart views, short-message warnings, and other functions. The phone app is designed to help users view and print temperature and humidity data concerning the transportation and storage of vaccines anytime and anywhere. Thus, this system provides a new vaccine management model for ensuring the safety and reliability of vaccines to a greater extent.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.484-487
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• 2004

Symmetric directional couplers are widely used in interferometers, switches, and various signal processing devices. Recently, several optical couplers using multimode fibers were reported, but these suffer from inefficient coupling of light into a branching fiber and/or low directivity. This paper presents the measurement and analysis of loss in the connection of optical fibers via the optical directional couplers. The functionality of the device is based on the principle that is symmetrical, the power in excited mode can be unambiguously directed into one of the output channel by varying and of its parameters. In this experiment, we measure the power of loss in the optical directional coupler at various radius of curvature. Before the measurement of loss in x-coupler, we polish the contact of the fiber surface in order that light can penetrate through another port. The results show that, when the radius of curvature is increased, the loss power is decreased and also approaches of the straight line case.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2002년도 동계연구발표회 논문개요집
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• pp.13-13
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• 2002

A Spatial light modulator (SLM) is a real-time programmable device having the modulation function of the amplitude, phase or polarization of an optical wavefront as a function of position via electrical or optical control signals. Various types of reusable SLMs with two-dimensional pixel arrays are centrally important devices in volumetric recording, data processing, pattern recognition, optical computer and other optical system. (omitted)

• Journal of Information Processing Systems
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• 제14권1호
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• pp.270-279
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• 2018

PCI Express (PCIe) bus, which was only used as an internal I/O bus of a computer system, has expanded its function to outside of a system, with progress of PCIe switching processor. In particular, advanced features of PCIe switching processor enable PCIe bus to serve as an interconnection network as well as connecting external devices. As PCIe switching processors more advanced, it is required to consider the different adapter card architecture. This study developed multipurpose adapter cards by applying an on-board optical module, a latest optical communications element, in order to improve transfer distance and utilization. The performance evaluation confirmed that the new adapter cards with long cable can provide the same bandwidth as that of the existing adapter cards with short copper cable.