• Journal of the Optical Society of Korea
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• 제16권4호
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• pp.401-408
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• 2012

The amplitude error of phase modulator used in closed-loop fiber optic gyroscope has occurred by the temperature dependency of the electro-optic coefficient, and also can be due to the square-wave dither signal which is generally applied for eliminating the deadzone. This error can cause bias drift and scale factor error. This paper analyzes the temperature dependency of the modulation amplitude and the relationship with the scale factor of the gyroscope, and deals with an amplitude control method. The error calculation logic considering the dither signal is implemented on the signal processing module. The result of experiments from a prototype gyroscope shows the effect of the modulation amplitude control and a considerable improvement on performances.

• 조명전기설비학회논문지
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• 제18권2호
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• pp.135-141
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• 2004

보호계전 시스템의 전류센서로 사용할 목적으로 편광분석형 광섬유 전류센서를 개발하였다. 광섬유의 선형복굴절에 의한 출력의 왜곡을 최소화하기 위하여 단일모드 광섬유를 미터 당 20회 이상 비틀고 그 끝단에 FRM(Faraday rotator mirror)을 부착하여 센서코일을 제작하였다. 광섬유 센서코일의 비틀림 정도를 달리하며 다양한 환경에서의 전류측정 실험을 행하였다. 실험결과로부터 광섬유 센서코일이 진동 등의 환경적 노이즈를 효율적으로 차단함을 알 수 있었으며 $\pm$3% 이내의 시스템 출력안정도를 얻었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권3호
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• pp.221-228
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• 2011

This paper describes 250-Mb/s fiber optic transmitter and receiver ICs for plastic optical fiber applications using a$ 0.18-{\mu}m$ CMOS technology. Simple signal and light detection schemes are introduced for power reduction in sleep mode. The transmitter converts non-return-to-zero digital data into 650-nm visible-red light signal and the receiver recovers the digital data from the incident light signal through up to 50-m plastic optical fiber. The transmitter and receiver ICs occupy only 0.62 $mm^2$ of area including electrostatic discharge protection diodes and bonding pads. The transmitter IC consumes 23 mA with 20 mA of LED driving currents, and the receiver IC consumes 16 mA with 4 mA of output driving currents at 250 Mb/s of data rate from a 3.3-V supply in active mode. In sleep mode, the transmitter and receiver ICs consume only 25 ${\mu}A$ and 40 ${\mu}A$, respectively.

• 한국항해학회지
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• 제21권3호
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• pp.67-74
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• 1997

This paper described the method and the result of making a dynamic fiber optic gyrocompass measuring the heading angles of ships by processing the output signal from a constant rotating fiber optic sensor and also showed the measurement to test the performance of our system. Considerig an economical view we designed and ordered a cheap medium grade fiber densors increased not fiber length but the diameter of a fiber sensing loop. The scale factor and noise was 267mV/deg/s and 2 deg/hr/$\sqrt{Hz}(1{\sigma})$, respectively. We made the dynamic fiber optic gyrocompass by this sensor. We measured the heading angles in an arbitrary direction to evaluate the accuracy of our system and the root mean square error was $0.4^\circ$. Moreover, we measured the angles ineach direction of $45^\circ$. successive rotation to know whether this system has distoritions in a specific direction or not and the root mean square error in this case was $0.5^\circ$.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 정보화시공 학술발표회
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• pp.61-78
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• 2001

Various kind of fiber optic gauge sensors are available that can be bonded to civil engineering structures such as bridges, dams, tunnels and pipelines. A new fiber optic long gauge has significant advantages over other fiber optic sensors. These gauges can vary in length from less than 10 cm up to 30 m and provide the structural engineer with accurate measurements of displacement. These displacements can be converted to strains by dividing the measurement by the long gauge length. Using new optical technology, the long gauge instrument developed by FOX-TEK can choose max. 30 meters of gauge length so as to measure the very early stress/strain correlation curve. And this gauge length to be extended up to 100 meter in 2002.

• 한국공작기계학회논문집
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• 제12권1호
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• pp.65-71
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• 2003

In a high speed spindle system it is very important to monitor the state of rotating rotor. Particularly in active control spindle system the position sensor must provide feedback to the control system on the exact position of the rotor. In order to monitor the state of a high speed spindle exactly, high accuracy and wide frequency bandwidth of sensors are important. The focus in this paper is to make a fiber optic sensor for monitoring rotor of magnetic bearing, to design the circuit for detecting optical signal, and to evaluation static and dynamic characteristics of fiber optic sensor.

• Journal of Biosystems Engineering
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• 제31권2호
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• pp.128-134
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• 2006

Frequent outbreaks of foodborne illness demand the need for rapid and sensitive methods for detection of these pathogens. Recent development of biosensor technology has a great potential to meet the need for rapid and sensitive pathogens detection from foods. An antibody-based fiber-optic biosensor and an automated reagents supply system to detect Listeria monocytogenes were developed. The biosensor for detection of Listeria monocytogenes in PBS and bacteria spiked food samples was evaluated. The automated reagents supply system eliminated cumbersome sample and detection antibody injection procedures that had been done manually. The biosensor could detect $10^4$ cfu/ml of Listeria monocytogenes in PBS. By using the fiber-optic biosensor, $2x10^8$ cfu/ml of Listeria monocytogenes in the food samples were detectable.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.772-777
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• 2008

Recent development of fiber optic sensors and wireless sensor technology, made structural health monitoring of railway structures cost effective. In this paper, a micro bending fiber optic rail pad sensors are evaluated for train axle force measurement. In order to assess the usability of FBG fiber optic sensors for short-term bridge measurement, the FBG sensors and conventional strain gauges are installed at the same points and the strain results are compared. Also the impact factors are calculated using the FBG strain responses and the results are compared with the conventional sensor responses. A running KTX train was instrumented with wireless sensor system to measure the vibration characteristics and the results are compared with conventional wire sensor system.

• 한국광학회지
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• 제5권4호
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• pp.493-498
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• 1994

광섬유 지연선로에 Cr/Au 박막을 증착하여 완전 광 슬라티드 링 통신망의 광 패킷 어드레스 검출기용 광섬유 정합 여파기를 제작하였다. 2.5Gb/s급 6-bit 어드레스 코드들에 대한 상관 파형을 시뮬레이션으로 얻었으며 측정된 상관 출력과 일치된 결과를 보였다.

• 한국광학회지
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• 제29권5호
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• pp.187-203
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• 2018

본 논문에서는 지난 40여 년간 이룩된 광통신 기술의 눈부신 발전 과정을 되돌아보고 예상되는 향후 발전 방향에 대하여 기술하였다. 특히, 초고속 대용량 광전송 시스템의 발전 과정에서 핵심적인 역할을 수행한 기술들을 역사적 관점에서 정리하였다. 본 논문은 광통신 분야에 새로이 입문하는 젊은 공학도들을 위하여 작성된 것이다.