Design And Fabrication Of Optical Microcavity Sensor Based On Micro-nano Fiber

Since Charles Kao created the first optical fiber of the world in the 1960 s, optical fiber technology has been dramatically improved. Now, the trend of optical fiber research is changed to the miniaturization of fiber devices. Many types of fiber based devices has been proved and experimentally demonstrated. Their applications range from microlaser, quantum optics, and nonlinear optics to label-free optical sensor. Micro-nano fiber based devices are the most prominent examples.In this thesis, we have systematically studied the fabrication of micro-nano fibers, and explored their applications in optical resonator and sensors. We have analyzed the micro-nano fiber Knot ring cavity based on m icro-nano fiber optic field transport theory, we got the light energy output formula of Knot ring cavity through theoretical calculations and the ring resonator output spectrum under different parameters.The preparation of micro-nano fiber has been summarized in chapter 3. We will analyze several common preparation methods: flame heating, hydrofluoric acid etching, drawn by the partial melting of bulk glass and polymer solvent stretching method. We use the first two methods to prepare micro-nano fibers, flame heating method uses an alcohol burner to melt ordinary single-mode bare fiber and the obtained stable micro-nano fiber diameter is of about 5?m and length is about of 5 to 10 cm. The diameter of micro-nano fiber prepared by Hydrofluoric acid is up to 1?m, the length can be prepared according to the experimental requirements. Then we analyze briefly the preparation method by glass and polymer and try to draw a polymer micro-nano fiber. Micro-nano fibers with diameter around 5 to 20 ?m have also been successfully obtained by drawing the polymer solvents.The micro-nano fiber based knot ring resonator was been studied on chapter 4. Experimental results show that the theoretical calculations of the micro-nano fiber are basically accurate, and verify that the resonant output spectrums of micro-nano fiber Knot ring cavity are correct from the experiments and simulations. By carefully bending a m icro-nano fiber to a ring cavity with diameter ~306 ?m, periodic resonate modes have been successfully obtained in the transmission spectrum. The measured FSR matched the theoretical prediction well. Finally, we have analyzed the potential application of the fabricated ring resonator in label-free detection.