Measurements of Dispersion Relationships of Side- polished Fibers Using Ti:sapphire Lasers

• Main Authors: Kuang-Yu Hsu, 許光裕
• Other Authors: Shiao-Min Tseng
• Format: Others
• Language: en_US
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/59889184680246501371

碩士 === 國立清華大學 === 電機工程研究所 === 82 === Side-polished fibers have found many applications in fiber-optic components.Tunable fiber couplers, fiber filters, fiber lasers were examples. Because of their useful applications, they were analyzed, made and calibrated in this thesis. Here, we used Si wafers as the polishing substrates. V-grooves were formed on the wafers and fibers were firmly embedded in them by epoxy. The grooves were designed by using CAD tools. Grooves were made on the wafers by micro-electronic techniques. To understand the properties of the side-polished fibers, numerical calculations were made. The geometries of side- polished fibers were designed accordingly. Fibers were polished using a home-made polisher. High performance 830-nm side-polished fibers were successfully made. By adding a liquid with a refractive index higher than the effective mode index on the polished region, evanescent field leak out to the unbounded liquid. The field intensity profile of a fiber is a function of wavelength. Thus, the attenuation of a liquid-cladded side-polished fiber is wavelength dependent. By using a tunable Ti: sapphire laser as the light source, we studied the characteristics of 830-nm side-polished fibers. The dispersion relationships of side- polished fibers were presented by using three different kinds of liquids in this thesis. Important parameters, e.g. effective interaction length and polishing depth were estimated. Our experimental results showed good agreements with theoretical calculations. The effective inter- action length as long as about 6mm was achieved. Suggested works include improvements of the polisher and further applications of Ti: sapphire laser in fiber-optics.