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The defense date of the thesis is 2004-09-01
The current date is 2019-07-19
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URN etd-0901104-214934 Statistics This thesis had been viewed 2316 times. Download 12 times. Author Yao-Chieng Chung Author's Email Address email@example.com Department Electro-Optical Engineering Year 2003 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 104 Title The study of all optic fiber micro-bibration sensors for Hydrophone applications. Keyword evanesce micro-vibration hydrophone fiber sensor fiber sensor hydrophone micro-vibration evanesce Abstract ABSTRACT
The characteristics and principles of the evanescent field for the side-polished single mode fiber are discussed, and the details of the various processes of fabricating the side-polished fibers are also described in this thesis. Furthermore, two kinds of the long period fiber grating (LPFG) micro-vibration sensors are presented. For increasing the sensitivity of the sensor, we polish the fiber into the evanescent region, and then fabricating a long period grating with rectangular groove structure on the side-polished surface by virtue of the ICP-RIE dry etching technique. This steep grating structure not only increases the sensitivity of the sensor, but also makes the sensing frequency up to the degree of MHz. In order to simplify the processes of the fabrication, we use the techniques of photolithography and thermal vaporization for the side-polished fiber to make up the thin film LPFG structure on the polished surface for acoustic wave sensing in the water. Several fabrication methods have been tested for the assessment of the sensitivity and stability analysis; two frequencies of the acoustic wave (520 Hz acoustic wave and 42K Hz ultrasonic wave) have been used in the experiment. The fiber grating sensors we proposed in this thesis posses several advantages, such as small size, easy fabrication, and low cost, as well as very good performances have been demonstrated and discussed for the hydrophone applications in the water. Several measurements are carried out, and the experimental results have very good frequency response from low to high frequency region.
Advisor Committee Woo-Hu Tasi - advisor
Hoshin. H. Yee - co-chair
Wen-Qin Ssi - co-chair
Files Date of Defense 2004-07-30 Date of Submission 2004-09-01