Research On Optical Properties Of WGM Microresonator In Aqueous Environment

In this thesis,we experimentally study the optical properties of the sausage-like whispering-gallery-mode(WGM)microresonator in the aqueous environment where a fiber taper is used as a light coupler.The preparation methods of the sausage-like microresonator(SLM),the fiber taper and the method of immersing the coupling system into the deionized water are introduced.In the experiment part of the thesis,firstly,we report our experiments on measuring the Q factor of the SLM with different length in deionized water.The results show that the SLM we fabricate can achieve a high Q of 107 in deionized water.Secondly,we study the resonant wavelength shift of the whispering-gallery mode caused by two kinds of changes of the aqueous environment.The effects of different concentrations of Cr(NO3)3 solution and liquid flow on the resonant wavelength shift are observed in the experiment.Finally we study the Fano resonance in the SLM.Fano resonances can be controlled to change periodically by moving the microresonator along the fiber taper horizontally.According to the Fano resonance phenomenon we observed,we establish a theoretical model and it explain well the phenomenon that the Fano resonances change periodically.