Research On Optofluidic Devices Using Silica Microcapillaries

As one novel kind of functional photonic devices, optofluidic devices simultaneously integrate both microfluidic techniques and photonic devices with a micro system, and enable the synergism of liquid-phase materials and solid optics system. Optofluidic devices greatly enhance tunability, reconfigurability and integrated functionality, and also broaden application areas and research potentials. Theoretical and experimental investigations on silica-microcapillary-based optofluidic devices are carried out. Main contents of this thesis are summarized as follows:The research background and significance of optofluidics are introduced, and research highlights on optofluidic devices based on silica micapillaries are summarized, along with their inherent structure features, schemes and applications. Both theoretical and experimental study are performed to investigate the structural features and optical properties of ring resonators based on silica microcapillaries.An all-optical tunable optofluidic ring resonator is proposed, and detailed operation scheme and fabrication are introduced. This all-optical controllable device achieves a large tuning range of up to 3.3nm, as well as a good sensitivity of 0.15nm/m W, taking advantages of the photothermal effect of magnetic fluid, and optics properties of the resonator scheme.An optofluidic polarization beam splitter based on a microcapillary is presented. Based on the analysis and study of the polarization-dependent characteristic of the whispering gallery modes within a microtube resonator, microfibers are adopted to realize an add-drop ring resonator. This splitter is able to separate two orthogonal polarization beams, and to achieve an optical spectrum with extinction ratios of 25 d B and 10 d B at the through and download port, respectively.