Non-destructive diameter measurement for high refractive index contrast fibers

• Main Authors: Yao-Yu Chang, 張耀宇
• Other Authors: Lon A. Wang
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/02388981406140224053

碩士 === 國立臺灣大學 === 光電工程學研究所 === 103 === The research of high refractive index contrast fibers, including novel semiconductor-core fibers has interested more and more scientists recently. But the diameter optical measurement of these fibers is a difficult challenge due to its high refractive index contrast and imaginary terms of core refractive index. We demonstrate a simple, novel and non-destructive method to measure both core and cladding diameters of high refractive contrast fibers (Δn>0.06) simultaneously which has not been reported. This method has potential to be a real-time measurement in the future. As the result of measurement, the accuracy of diameter measurement using this method can reach 97% for index-oil-cored-fibers (Δn=0.36) and 96% for silicon cored fibers (Δn=2.97+0.88i) currently. For silicon cored fibers, the effective core diameter measurement range can be from 6.3μm to 9.3μm when the corresponding cladding diameter is 15μm. According to the simulation, this method may suitable to measure cladding diameter ranging from 126 to 15μm for Si-cored fiber. It’s better than Optical microscope (OM) examination since core diameter in the OM picture is inaccurate due to Snell’s law. This measurement method is suitable for silicon cored fibers (Δn=2.97+0.88i) and high refractive contrast fibers with core refractive indices ranging from 1.52 to 1.82 due to the availability of refractive liquid oil ranging from 1.82 to 4.15. Besides, this method can be used in measuring diameters of different types of silicon cored fiber in the same database.