• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.5
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• pp.395-402
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• 1991

Submarine Optical Fiber Cable Link becomes a major transmission madi a in many countries and Continents thanks to development of low attenuation fiber and its capability of carryung broadband data. United States of America and Japan are aggressively planning to construct international submarine optical fiber links in North-East Asia. But the links do not connect Korea and Korea becomes isolated in the international communication network. This paper shows a strategy on submarine optical fibre cable links that make Korea a HUB station in North East As a without heavy investment.

• Polymer Science and Technology
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• v.7 no.2
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• pp.179-192
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• 1996

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.2
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• pp.50-58
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• 1983

In this paper, a field trial of the Korean-made optical fiber communication system is described. This system was installed between Gu-Ro and Ann-Yang telephone offices on November 1981, and carries a 44.7Mb/s NRZ signal(672 voice channel equivalent). For this trial, optical fiber cable, optical terminal equipment, optical repeater, fusion splicer and measurement equipment have been developed. Employing graded index optical fiber at a wave length of $0.85\;\mu\textrm{m}$, average optical attenuation and splicing losses of 3.6 dB/km and 0.4 dB, resectively, were realized. With link margins of 8~20dB and bit error rate of less than $10^{-10}$, this system has been carrying live traffic between Seoul and Ann Yang telephone offices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.6
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• pp.357-364
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• 2014

In this paper deals with PON Remote monitoring solution using Reflecting Filter. The current FTTH-PON can not be monitored in real time that Optical cable fault and Quality degradation of Splitter. To solve this problem, Monitoring can make Feeder Network and Splitter that Reflecting filter development using the basic structure of Fiber Bragg grating. Reflecting Filter is Quality Monitoring System shall provide tools for user to view and analyze degradation of cables and splitter in particular predict any gradual component degradation(Optical cable bending, splice, connector, etc) before it becomes service impacting. The Reflecting Filter solution is splitter down and confirm the fault location of optical cable and it will send central control station can be monitored system an alarm to the OLT. In other words, wavelength side branches Mating existing communication affairs (Coupler) using the core of one optical wavelength for live monitoring two wavelengths and sends the subscriber side modem and aggregation switch device remotely using a reflective optical line filter monitoring the study of the system. this study can development of Reflecting filter improve the average processing time of Optical cable fault and efficient Maintenance of the network.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1547-1549
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• 1994

In recent years, fiberoptic technology is becoming indispensable in establishing communication networks due to its low loss, high capacity and non-inductive properties. In the power industry as well, the technology is being required to cable and facility monitering, and control system. But, duct in the manhole and space in the culvert are required to fiberoptic cable that is separated from power cable. Therefore, some cable makers and R&D has been studying the composite fiber/power cables. This report introduces the outline of ABF system, construction and properties of optical composite power cable that used ABF technology.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2450-2452
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• 1999

Presently, it is now developing the optical remote gas sensor system which can measure combustible gases such as $CH_4$ and $C_2H_2$ generating by partial discharges inside the cable and connection parts to detect thermal deterioration of Oil-Filled (OF) power cable at the appropriate time. It is the most important parameter to select central wavelength of laser diode (LD) by analyzing the absorption bend of measuring gases in the infrared region. In this research, we proposed the optical spectrum analyzer to absorption band of $CH_4$ and $C_2H_2$ for the preliminary research of optical fiber gas detecting system.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.1
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• pp.1-7
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• 2008

Submarine cable is the most important IT infrastructure for international communication across oceans. However, a cable fault rarely happens by ship's anchor, fishing gears, submarine earthquake, and so on, and we need to improve on repair time for the reducing expenses of cable repair ship as well as the stability of high-capacity submarine optical network. There are several kinds of cable faults such as Shunt fault, Cable cut, Open fault and Fiber break. When a fault is occurred, cable landing stations(CLS) have to analysis failure quickly and accurately to find the type and the location of a cable fault. During the repair period, CLS should swiftly perform the tests requested by cable repair ship. In order to make rapid progress on cable repair, CLS test technique is very important. So, in order to reduce the repair time, this paper is studying the CLS test techniques of locating a submarine cable fault and of checking the splicing point performed by cable repair ship.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1100-1109
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• 2006

In this study, two different technologies which can measure temperature simultaneously at many points are introduced. One is to use a thermal sensor cable that is comprised of addressable thermal sensors connected in parallel within a single cable. The other is to use an optic fiber with Distributed Temperature Sensing (DTS) system. The difference between two technologies can be summarized as follows. A thermal sensor cable has a concept of 'point sensing' that can measure temperature at accurate position of a thermal sensor. So the accuracy and resolution of temperature measurement are up to the ability of the thermal sensor. Whereas optic fiber sensor has a concept of 'distributed sensing' because temperature is measured by ratio of Stokes and anti-Stokes component intensities of Raman backscatter that is generated when laser pulse travels along an optic fiber. It's resolution is determined by measuring distance, measuring time and spatial resolution. The purpose of this study is that application targets of two temperature measurement techniques are checked in technical and economical phases by examining the strength and weakness of them. Considering the functions and characteristics of two techniques, the thermal sensor cable will be suitable to apply to the assessment of groundwater flow, geothermal distribution and grouting efficiency within 300m distance. It is expected that the optic fiber sensor can be widely utilized at various fields (for example: pipe line inspection, tunnel fire detection, power line monitoring etc.) which need an information of temperature distribution over relatively long distance.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.189-194
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• 2008

The main object of this paper is that it's possible to monitoring the deformation of cable in the tensegrity structure. always monitoring system of Fiber Bragg Grating(FBG)Sensor is described. The measurement of parts on the cable is very important. We make an experiment with measuring deformation of cable in the tensegrity structure to the pressure conditions. In the result of experiment, the fiber sensors showed good response to the pressure conditions. Therefore, We could calculate the deformation of cable structure and be possible health monitoring of the tensegrity structure.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.493-499
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• 2006

Arbitrary graded-index HOF(Hollow Optical Fibers) are analyzed using the modified Airy function, and the corresponding eigenvalue equation that renders precise results is derived. For graded index HOF, the gradient of an evanescent field in hollow region could be adjusted more sharply than the conventional step-index HOF and the feasibility of more effective atom-guiding is confirmed.