Theoretical Study Of Micro-and Nano-based Fiber Ring Resonator

As one of the greatest inventions in the 20th century, optical fiber has gone through a century history. With improvement of material life and scientific & technological progress, Needs and aspirations for further development in optical fiber technology is fully demanded. When reviewing electronic devices history, we find optical technologies undergo the same experience as electronic technology does. That is a trend towards the miniaturization. Due to historical reasons, the every advancement of optical fiber technology is accompanied by development of electronic technology. So the fiber-optic technology is inevitably to follow the trend of electronic technology.At the beginning, background of microfiber technology research is introduced. The current microfiber technology, manufacture methods as well as theory of microfiber are reviewed. We present a variety of optical devices based on micro studies. Finally, theories and applications of fiber-optic ring resonator are proposed.In the paper, we firstly analyzed the propagation property of microfiber. On condition of weak waveguide approximation, we studied the distribution of light field of microfiber and concluded that certain light as form of evanescent wave travel on microfiber surface. Under the weak coupling approximation model, coupling model between two paralleled microfibers is also analyzed. Optical energy transmits in forms of cosine function alternatively between two parallel microfibers. The beat length of energy is related to microfiber diameter, distance and refractive index of environment.Based on coupling theory of two parallel microfibers, the first main work of this thesis is to analyze properties of microfiber ring resonator. We calculated the transmission formula of ring resonator and output spectrum when different parameters applied in the ring resonator. At the same time, we also studied the ring resonator with a variety of form combination, including paralleled double-loop resonator and series loop resonator. Through calculation, we obtained the corresponding transmission formula and analyzed the output spectrum of phase characteristics.The second main work in this paper is that we adopted two methods to fabricate microfiber. We used an alcohol burner to heat single-mode fiber and draw it when single-mode fiber is under molten state. The microfiber can be drawn to 10 cm in length and 1 ~ 2μm in diameter, 10-5 in diameter uniformity. The second way is through organic solvent polymer to draw microfiber. By this way, the microfiber can be drawn to 10 cm in length and 1μm in diameter, 10-5 in diameter uniformity. The third method is similar to the second and the first one. We used hot plate at high temperature to heat polymer and draw a microfiber. The property of this microfiber is similar to the one by second method.The third main work of this paper is to fabricate microfiber resonator. Several experiments are conducted to prove the transmission theory. Experimental results agree well with calculations. The calculation can be applied to a group of resonator combination, such as paralleled connection loop resonators and series connection loop resonators. At the same time, by advantages of our fiber optic sensing laboratory, a lot of experiments are conducted and related results have been published.