• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.770-773
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• 2003

To measure discharge breakdown acoustic signal, Fabry-Perot interferometer fiber optic sensor is used. Fiber optic sensor array can measure the partial discharge acoustic signal caused by defect of power facilities such as power cables, transformers and gas insulation. Fabry-Perot interferometer is selected as an fiber optic sensor array. It is shown that Fabry-Perot fiber optic sensor array detected discharge breakdown acoustic signal, effectively.

• 센서학회지
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• 제14권2호
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• pp.91-95
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• 2005

A fiber Fabry-Perot interferometric sensor for the measurement of current flowing into a small fuse have been studied. The proposed current sensor was fabricated with a fiber Fabry-Perot interferometer attached close to a fuse line inside a small fuse. The fiber Fabry-Perot interferometer used in the experiment had the 10 mm cavity length and the 3.5 % reflectance mirrors. The phase shift of the output signal of the current sensor was proportional to the square of current applied to the fuse and the sensitivity of the current sensor was 0.87 degree/$mA^{2}$. The experiment results show that this sensor can be used for measuring current flowing into the fuse.

• 한국음향학회지
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• 제22권7호
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• pp.585-591
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• 2003

본 연구에서는 소형화 및 경량화의 특성을 가진 Fabry-Perot형 간섭계를 구성하였다. 음향이 광섬유의 횡방향으로 감지되도록 센서 헤드부를 1㎝정도로 제작하고 총 길이가 9.5㎝인 광섬유의 양단을 단순 지지토록 하였다. 센서의 음향 감지특성을 관찰하기 위하여 무지향성 스피커를 이용하여 음향신호를 인가하였다 횡방향으로 입력된 음향 신호를 광섬유 센서와 마이크로폰이 감지한 신호를 비교하였다. 1㎑ 이하의 신호에서는 광섬유 센서가 마이크로폰보다 감지 특성이 좋으나 2 ㎑에서는 광섬유센서의 감지 특성이 감소하였다. 이것은 제작된 광섬유 센서의 지지구조의 특성을 나타낸 것이며 실험을 통하여 Fabry-Perot 간섭계용 센서는 횡방향의 음향을 잘 감지함을 확인하였다. 이러한 형태의 센서는 지능구조물의 건강진단 모니터링 분야에도 적용가능 하리라 판단된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.342-345
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• 2005

To detect external acoustic signal, fiber optic sensor array using Fabry-Perot interferometer which had benefit of minimize and light-weight was used. The sensor head has 1cm in length, total length of fiber is 9.5cm, and the sensor supported at both ends, simply. External sound applied in lateral direction and detected two signals were compared each other. It was confirmed that the Fabry-Perot interferometric sensor array detected acoustic signal, effectively.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.141-142
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• 2007

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2186-2188
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• 2000

A fiberoptic sensor using an SLD as a light source has been studied. The sensor system employs an intrinsic fiber Fabry-Perot interferometer as a sensing tip and a fiber Mach-Zehnder interferometer as a processing one. A free loading test for temperature application shows that the fiberoptic sensor has a wide-dynamic range as well as high resolution. Due to the inherent property of the optical fiber itself and the intrinsic Fabry-Perot interferometer. the fiberoptic sensor gives obvious benefits when it is applied to harsh environments to monitor some physical parameters such as temperature, strain, pressure and vibration.

• Journal of Magnetics
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• 제18권2호
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• pp.173-177
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• 2013

Cantilever-detected high-frequency electron spin resonance (ESR) is a powerful method of sub-terahertz and terahertz ESR spectroscopy for a tiny magnetic sample at low temperature. In this technique, a small magnetization change associated with ESR transition is detected as deflection of a sample-mounted cantilever. So far, we have succeeded in ESR detection at 370 GHz using a commercial piezoresistive microcantilever. The spin sensitivity was estimated to ${\sim}10^{12}$ spins/gauss. In order to further increase the sensitivity, we adopt a fiber-optic-based detection system using a Fabry-Perot interferometer in place of piezoresistive system. Fabry-Perot cavity is formed between an optical-fiber end and microcantilever surface, and a change in the interference signal, corresponding to the cantilever deflection, is sensitively detected. This system is suitable for low-temperature and high-magnetic-field experiments because of its compact setup and less heat dissipation. In this study, performance of Fabry-Perot interferometer is evaluated, and its application to cantilever-detected ESR measurement is described.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 하계학술발표회
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• pp.298-299
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• 2003

초음파는 일반적으로 물질의 내부결함을 측정하거나 결정입경과 같은 물질의 특성을 측정하는데 사용된다. 현재 초음파를 검지하는 방법으로는 탐촉자를 물질에 접촉시켜서 초음파를 측정하는 접촉식 방법이 널리 사용되고 있다. 따라서, 이러한 접촉식 초음파 검출방법은 원격탐사를 하는데에 어려움이 있다. 이런 문제점을 보완하기 위하여 본 연구에서는 패브리-페로 간섭계(Fabry-Perot interferometer)를 이용하여 비접촉식으로 초음파를 검출하는 방법에 대하여 실험하였다. (중략)

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권12호
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• pp.691-697
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• 2000

A fiberoptic sensor using a low-coherence SLD as a light source has been studied. The sensor system employing an intrinsic fiber Fabry-Peort interferometer as a sensing tip and a fiber Mach-Zehnder interferometer as a processing one, overcomes the ambiguous reading caused by the highly periodic natrue of conventional high-precision interferometric sensors and provides unambiguous identification of the desired phase among several candidates on the transfer function of an interferometric signal. A tentative application to the temperature sensor shows the potential that the fiberoptic sensor has a side-dynamic range of $0-900^{\circ}C$ as well as reasonable resolution higher than $0.1^{\circ}C$ without ambiguity. Due to the inherent property of the optical fiber itself and the intrinsic fiber Fabry-Perot interferometer, the proposed fiberoptic sensor will give obvious benefits when it is applied to harsh environments to monitor some physical parameters such as temperature, strain, pressure and vibration.

• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.113-118
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• 1989

By using the single mode optical fiber, we fabricated Fiber-optic Fabry-Perot interferometer (FFPI). The change over a wide range in the optical path length of a FFPI is observed. The temporal movement of the interference fringes by external condition to P.Z. T) is converted to circular motion on an oscilloscope display and then recorded with a micro-computer. The two output voltages of the D/A converters are applied to X and Y terminals of oscilloscope to display circular motion on oscilloscope. Thus the direction of phase shift can be determined with observing the direction of circular motion. The variation of the optical length can be measured by calculating the angle of spot of circle with an accuracy of λ/90 wave length due to variation of temperature in this system 2.7x10-4$^{\circ}C$.