Jaehee Park

Plastic Optical Fiber Refractive Index Sensor Employing an In-Line Submillimeter Hole

An in-line submillimeter hole fabricated by micro-drilling plastic optical fiber (POF) directly has been proposed as a compact refractive index sensor. Since the hole behaves as a concave lens if it is filled with a liquid having lower refractive index than that of the fiber core, transmittance increases in proportion to the refractive index. Analysis of the sensor transmittance has been performed using a simple ray optics model. Through immersing a 1.5-mm POF with a 0.35-mm-radius hole into various liquids, transmittance of the sensor has been measured at 670 nm. It has been shown that the experimental and analytical results are in excellent agreement.

Reflective Side-Polished Optical Fiber Submersion Sensor Using an Optical Fiber Mirror for Remote Sensing

A reflection-type side-polished optical fiber submersion sensor (RSS) with an optical fiber mirror for remote sensing is proposed. When compared with a conventional transmission-type side-polished optical fiber submersion sensor (TSS), the RSS with an optical fiber mirror provides an improved response, and allows efficient remote submersion sensing. In experiments, the RSS with an optical fiber mirror detected submersion with 1 dB increased throughput power gain when compared with a conventional TSS, and provided efficient remote sensing at a distance of 1 km based on the resonance wavelength shift and transmission power gain

Fabrication and Mode Coupling of Long-Period Fiber Grating by Winding a Wire Around an Optical Fiber Fixed to a Cylindrical Metal Rod

© 2013 Lee et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Fabrication and Mode Coupling of Long-Period Fiber Grating by Winding a Wire Around an Optical Fiber Fixed to a Cylindrical Metal Rod

Plastic optical fiber sensor based on in-fiber microholes for level measurement

A plastic optical fiber (POF) sensor with in-fiber microholes for level measurement is investigated. The sensor has eight 0.9-mm-diameter holes spaced 5 cm apart and fabricated by micro-drilling. When water is poured into a measuring cylinder equipped with a POF sensor for level measurement, the sensor transmittance increases with the number of holes immersed in water. The experimental data are in good agreement with the theoretical data. The research results show that a POF sensor with in-fiber micro-holes can be used to measure liquid level.

Fiber-optic interferometric temperature sensor using a hollow fiber

A fiber-optic interferometric sensor for measuring temperature in the range from 28degC to 100degC is developed using a hollow optical fiber with an air-hole around the center axis. This sensor is formed with a 13 mm long hollow optical fiber with one end joined to the single mode fiber by a fusion splicing technique and the other cleaved end. The fabrication procedure provides easier and cheaper technologies for fiber-optic interferometric temperature sensors. This temperature sensor has a linear response and high resolution.

Plastic optical fiber level measurement sensor based on side holes

Plastic optical fiber level measurement sensor based on in-line side holes is investigated theoretically and experimentally. The sensor consists of a plastic optical fiber with in-line side holes spaced about 5 cm apart. The 0.9 diameter in-line side holes were fabricated by micro-drilling. An analytical expression of the sensor transmittance was obtained using a simple ray optics approach. The measurements of the sensor transmittance were performed with a 55 cm height Mass cylinder. Both results show that the sensor transmittance increases as the number of side holes filled with water increases. The research results indicate that the plastic optical fiber based on in-line side holes can be used for water level measurement.

Fiber-Optic Inteferometric Voltage Sensor using a Hollow Fiber

A fiber-optic interferometric voltage sensor with high sensitivity is investigated. The fiber-optic voltage sensor is composed of an In-Line Michaelson interferometer bonded on a PZT. The In-Line Michaelson interferometer is a hollow optical fiber spliced to a single-mode fiber at one end and cleaved at the other end. The phase shift of the sensor output signal was induced by the applied AC voltage. The relation between the amplitude of the applied voltage and the phase shift of the sensor output signal was approximately linear and the sensitivity was radian/V.

Reflection-type side-polished fiber submersion sensor using an optical fiber mirror in a manhole

A reflection-type side-polished optical fiber submersion sensor with an optical fiber mirror in a manhole is proposed. When this sensor is submerged into distilled water in a manhole and the measurement is made at about 1km from the sensor, the throughput power gain is changed by about 2.04dB at 1540nm and the resonance wavelength shifts from 1540nm to 1541.6nm.

Fabrication and Characteristics of the Fiber Device Based on Long-period Fiber Gratings at the Locations Under Applied Pressure

An optical fiber device is fabricated that is formed LPFGs only where pressure is applied, and the characteristics of the device are investigated. The fabricated device is composed of a 60cm-long metallic rod, with long period gratings of on the upper side and a rubber cover. In this device, gratings are only formed when pressure was applied to a spot, to which pressure was applied, and the formed gratings had the same transmission property regardless of spot, to which pressure was applied. We measured the optical transmission property of the fabricated device and found its usability as an optical fiber load sensor to measure weight.

Fiber Fabry-Perot interferometric sensor for the measurement of current flowing into a small fuse

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/. The experiment results show that this sensor can be used for measuring current flowing into the fuse.