The Research Of Novel Optofluidic Devices In Design And Fabrication And Its Applications

Optofluidics, where optics and microfluidics are working together, is defined as a newfield and technology. Compared with traditional rigid optical devices, optofluidic elementsshow features due to the miniaturization in the size, various tunable mechanisms andintegration for analysis and detection of biochemistry. This dissertation is mainly concernedwith the optofluidic devices and its applications based on PDMS. Moreover, the opticalproperties of optofluidic devices are characterized and discussed.We firstly report the fabrication of magnetic fluid core optical fiber. Paraffin-basedFe3O4magnetic fluid is selected as the liquid and filled in a hollow core fiber. The magneticparticle size is10nm. Transmitted intensity of magnetic fluid core optical fiber dependent onmagnetic field is studied. The theoretical about mode calculation is in accordance with theexperimental results and the optical loss is also given.The integration of dye lasers with microfluidics facilitates the implementation of“lab-on-a-chip” for analysis of biochemistry. We studied microring dye laser in the abovecontext. The PDMS chip is fabricated through conventional lithography and the rapidprototyping. The threshold is relatively high resulting from cavity loss. A reduced threshold isrealized by the unique design of the bus waveguide across the center of the microringstructure.We experimentally demonstrated a tunable interferometer controlled by diffusion throughthe laminar flow of two miscible liquids. The results show that the peak numbers of theinterference curves are increasing with the flow rate ratio. A program is written in COMOSL to calculate the refractive index gradient at different flow rates. Micrographs of the differentlocation of the interface under the different flow rate ratio are given. Such an interferometerpaves the way for biochemical tests in sensing system.Droplet microfluidics has drawn much attention due to its intensive applications. A signalgenerator is realized by droplet grating which is generated through a typical microfluidicT-junction. Experimental results show that the frequency and waveforms of signals can bemodulated by flow rate ratio. The coding device serves as an example for applications byintegrating the signal generator with another T-junction. The investigation of optofluidicdevices facilitate the development of integrated optics and also offer more functionalities to“Lab-on-a chip”.