• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.640-643
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• 1996

In this paper, a sensitivity of the fiber optic pressure sensor in water is demonstrated. A single mode optical fiber Mach-Zehnder interferometer used to detect the change in optical path length produced by the change of fiber optic strain in water. The sensitivity with this system measured 100.mu.psia through an experiment in the static response.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.142-148
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• 2004

In this paper, to detect exciting frequency on the latticed fence structure, fiber optic sensor using Sagnac interferometer was fabricated and tested. The latticed structure fabricated with dimension of 180 cm wide and 180 cm high, the optical fiber, 50 m in length, distributed and fixed on the latticed structure. Single mode fiber, a laser with 1,550 m wavelength, and $3{\times}3$ coupler were used. Excited vibration signal applied to the latticed structure from 200 Hz to 1 KHz. The detected optical signals were compared to the detected acceleration signals and analyzed on the time and frequency domain. Based on the experimental results, fiber optic sensor using Sagnac interferometer detected exciting frequency, effectively. This system can be applied to the structural health monitoring system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.792-796
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• 2003

In this paper, to detect external sound frequency on the latticed structure, fiber optic sensor net using Sagnac interferometer was fabricated and tested. The latticed structure fabricated with dimension of 50cm in width and 50cm in height, the optical fiber, 50m in length, distributed and fixed on the latticed structure. Single mode fiber, a laser with 1,550nm in wavelength, 2${\times}$2 coupler were used. External sound signal applied to the fiber optic sensor net and the detected optical signals were compared and analyzed to the detected microphone signals against time and frequency domain. Based on the experimental results, fiber optic sensor net using Sagnac interferometer detected external sound frequency, effectively. This system can be expanded to the structural health monitoring system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.7
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• pp.569-576
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• 2004

In this paper, to detect external sound frequencies on the latticed structure, fiber optic sensor net using Sagnac interferometer was fabricated and tested. The latticed structure was fabricated with a dimension of 50 cm in width and 50 cm in height. The optical fiber of 50m in length was distributed and fixed on the surface of the latticed structure. Single mode fiber, a laser with 1,550 nm in wavelength, 2 ${\times}$ 2 coupler were used. External sound signal, 240 Hz, 495 Hz, 1.445 kHz, 2k Hz, applied to the fiber optic sensor net and the detected optical signals were compared to the detected microphone signals against time and frequency domains. Based on the experimental results, fiber optic sensor net using Sagnac interferometer detected external sound frequency, effectively. This system can be expanded to the structural health monitoring system.

• The Journal of the Acoustical Society of Korea
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• v.21 no.1E
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• pp.25-30
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• 2002

We report on the development of a fiber optic hydrophone consists of a sensing Michelson interferometer and a compensating Mach-Zehnder interferometer for optical path length compensation. The double interferometer configuration has the following advantages: the hydrophone can be made more small; a laser source with a relatively short coherence length can be used; and the compensating interferometer can be located near the signal processing electronics, far away from the sensing interferometer and noise introduced by reference arm can be greatly reduced. The performance of the hydrophone is evaluated experimentally by immersing the sensing interferometer in a water tank to detect underwater acoustic signals generated by an acoustic wave projector. Experimental results show that over the frequency range of 1 to 4 kHz, the hydrophone has an almost flat response with an average normalized sensitivity of -302 dB re 1/ μ Pa.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.234-237
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• 2002

To detect external vibration signals on the latticed fence structure, distributed fiber optic sensor using Sagnac interferometer was fabricated and tested. The latticed structure fabricated with dimension of 170cm in width and 180cm in height, the optical fiber, 50m in length, distributed and fixed on the latticed structure. It was verified the sensitivity of the Sagnac interferometer using the PZT phase modulator. Fiber optic external vibration signal spplied to the latticed fence structure from 100Hz to several kHz. The interferometeric fiber optic sensor detected the excited vibration signal very effectively without any signal processing. The detected optical signals were compared and analyzed to the detected acclerometer signals.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.533-534
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• 2010

Fiber optic sensor has bee widely used in the industrial applications. For the application of acoustic detection of the high voltage electric transformer Sagnac interferometer can be used. In this paper several different materials of mandrel were used in the fiber sensor array. Based on the transformer oil fiber optic sensor is more sensitive than in the air.

• Proceedings of the KSME Conference
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• 2003.04a
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.707-708
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• 2012

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.411-414
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• 2008

The study is about simulation of optical circuit for oneself performance evaluation of Fiber Optic Gyro(FOG) closed-loop controller board. The Fiber Optic Interferometer Simulator is used a digital signal processing for cosine response specificity output of fiber optic coil about input rate. Response specificity of the fiber optic coil is $Vo(t)=K3[1+\cos\{K1(Vm(t)-Vm(t-{\tau}))+K2\}]$. Also the Fiber Optic Interferometer Simulator is able to confirm a output value with K1, K2 and K3 input. The fiber Optic Interferometer Simulator is able to oneself performance evaluation without fiber optical circuit. Because, it is the very same cosine response specificity of real fiber optic coil about input rate.