• Journal of the Optical Society of Korea
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• 제12권3호
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• pp.166-169
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• 2008

The submersion monitoring system based on a reflective side-polished optical fiber submersion sensor with an optical fiber mirror was shown to be an effective alarm system with remote monitoringwhen the drainage capacity of a common utility duct is exceeded due to heavy rainfall. The proposed sensor was connected to an existing installed optical fiber network at a height of 250mm in a common utility duct, and then tested under sample materials(distilled water, river water, sea water, foul water, muddy water, petroleum, edible oil) at a distance of 1km from the sensor for remote sensing. In experiments, the proposed real-time sensor system reduced maintenance cost and improved monitoring efficiency by using a reflection-type side-polished optical fiber submersion sensor efficient for remote monitoring of a common utility duct.

• 센서학회지
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• 제32권1호
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• pp.51-54
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• 2023

We investigated a humidity sensor based on a polyimide-coated side-polished optical fiber. The polyimide film absorbed moisture, causing the resonant wavelength of the sensor to shift to a longer wavelength owing to the changes in the optical properties of the film. The experimental results showed that the resonant wavelength of the device shifted by 17-18 nm when relative humidity changed from 30% to 90%.

• 센서학회지
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• 제19권6호
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• pp.428-434
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• 2010

In this study, a novel gas sensor based on evanescent field coupling between single mode side polished fiber and solvatochromic dye dispersed polymer waveguide was demonstrated. We fabricated a side polished optical fiber device as a volatile organic compounds gas detector. Solvatochromic dye was coated on the top of the side polished optical fiber to take advantage of evanescent field coupling. The solvatochromism can be defined as the phenomenon whereby a compound changes color, either by a change in the absorption or emission spectra of molecule, when reacted in different VOCs. The device reacted to polarity gases like a hexane, butane, xylene etc. The resonance wavelength was shifted by the xylene concentration which range was 0.1 ppm ~ 100 ppm. Also, the response with the concentration was lineer and the detection limit was 0.1 ppb.

• Journal of the Optical Society of Korea
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• 제7권3호
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• pp.180-187
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• 2003

A theoretical presentation by using a three-dimensional finite difference beam propagating method (3-D FD-BPM) for the evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with a perfect conductor (PEC) on one side. The coupling and propagation of light are found to depend on both the relationship between the refractive index values of two structures and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of a PWGCC is presented with the distribution of electric fields in xy - plane and the absolute amplitude of electric fields along the x and y axis. The power of the light propagation in a fiber decreases exponentially along the fiber axis as it is transferred to the PWGCC, where it is carried away.

• 한국광학회지
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• 제15권3호
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• pp.222-228
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• 2004

측면 연마 광섬유를 이용하여 가변 광 감쇠기를 실험적으로 구현하였다. 오버레이 물질로는 poly(vinylidene fluoride)와 poly (methyl methacrylate) 고분자 혼합체를 사용하였다. 혼합고분자의 온도를 변화시켜 오버레이의 굴절률을 조절하였고, 그로 인한 소산장 결합정도를 변화시켜 광섬유로부터 추출되는 광량을 조절하였다. 삽입손실은 0.1 ㏈ 이하였으며 30㏈이상의 감쇠를 실현하였다.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.337-341
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• 2010

A high sensitivity fiber optic temperature sensor based on a side-polished fiber (SPF) coupled to a tapered multimode overlay waveguide (MMOW) is proposed and studied. Both tapered and non-tapered MMOW were considered to study the effect of tapering of MMOW on the characteristics of the device and to investigate the criticality of the uniformity of the multimode overlay waveguide over the SPF. Present study shows that tapering of the MMOW can be used to tune the desired wavelength range without any loss in the sensitivity. Sensitivity up to 9 nm/$^{\circ}C$ within the temperature range of 25 to $100^{\circ}C$ can be achieved with the proposed sensor, almost 6 times higher compared even to state-of-the-art high-sensitivity grating-based fiber optic temperature sensors.

• 대한전자공학회논문지SD
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• 제41권10호
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• pp.57-62
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• 2004

단일 모드 광섬유의 측면을 일부분 연마하여 연마된 상부에 열 광학 폴리머 층과 금속열선을 형성한 광섬유형 전류센서를 보고한다. 금속 열선에 인가된 전류에 의해서 발생하는 저항열은 폴리머 층의 굴절률을 변화시키고 광섬유의 소산장을 통한 광 감쇄를 유도하게 된다 두 가지 유형의 센서구조를 제안하였고 전류센서로서의 특징을 조사하였다.

• 한국전기전자재료학회논문지
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• 제27권3호
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• pp.195-198
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• 2014

In this paper, a measurement method to obtain the optical properties of a liquid base on a side-polished single mode fiber was proposed and demonstrated. The device showed periodic resonance coupling against wavelengths. The refractive index and dispersion characteristics of a liquid were calculated by use of the spacings of periodic resonance wavelengths of the device. The thermo-optic coefficient of the liquid was obtained by monitering the shift of resonance wavelengths of the devices with change of environmental temperature.

• 전자공학회논문지D
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• 제36D권9호
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• pp.50-55
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• 1999

단일모드 광섬유의 한쪽 측면을 코어 가까이 연마한 광섬유와 그 위에 덮혀진 정합액 사이의 광결합을 이용한 가변 광 감쇠기를 제안하였다. 광섬유모드와 방사모드사이의 결합으로 인하여 정합액의 미세한 굴절률 변화는 큰 광손실의 변화를 발생시킨다. 정합액의 열광학 효과를 이용하여 광손실을 제어하였다. 실리콘 V홈을 이용하여 측면 연마된 광섬유 블록(block)을 제작하였다. 실험결과 $5^{\circ}C$ 정도의 온도변화로서 감쇠량을 최대와 최소사이에서 제어 할 수 있었다. 제작된 소자의 편광의존성 손실은 0.5 dB이었고, 삽입 손실은 0.2dB 이었다.

• 센서학회지
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• 제13권3호
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• pp.207-212
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• 2004

We have investigated the optical characteristics of a directional coupler made of a side-polished polarization maintaining fiber in contact with a multimode planar waveguide and its applications as sensors. A device structural condition to achieve the polarization insensitive wavelength response has been presented. The fabricated devices revealed a superior immunity to the bending and the deformation of PM fibers in the input section. It is experimentally shown that the proposed device is suitable for a remote fiber sensor.