| Summary: | 碩士 === 國立屏東科技大學 === 車輛工程系所 === 96 === In this thesis, the sensitivity of step-index polymer optical fibers (SI POFs) and their applications are explored. The power losses in deformed grooved POFs are analyzed both experimentally and numerically. An elastic-plastic three-dimensional finite element model is used to simulate the deformation which takes place near the grooved region of the elongated POF. The power losses in the SI POFs subjected to cyclic loads are also studied experimentally. The parameters discussed are cyclic loads and elongation speeds.
The results indicate that elongation significantly affects the power loss of a grooved SI POF. The power loss rate increases as the POF groove depth increases. In this study, the power loss in a grooved POF can reach as high as 53%. The grooved POF has been successful used as a medical sensor. The results also show that a slower elongation speed or a larger cyclic load results in a larger power loss as the POF is subjected to a cyclic load. The power loss can reach as high as 21% after 100 cyclic loads. Based on the experimental results, a curve-fitted empirical equation is proposed to estimate the power loss using the number of cycles for various elongation speeds and cyclic loads. A good agreement between the measured results and the results obtained from the proposed empirical equation is observed. The maximum difference is less than 6 %.
Keywords : Grooved POF, power loss, elongation deformation, cyclic load, sensor
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