Research Of The New Microfluidic Waveguide Devices

The variable microfluidic waveguide devices is a novel of optical component with many advantages, such as adjustable optical performance, small size, light weight, high stability, and ease of integration, which has wide potential application in many fields ranging from information photonics to optical information processing, bio-sensing, medical diagnosis and many other fields. However, there are still some shortcomings in the published reports about variable microfluidic waveguide devices, and these are still in their early stage of research and application. As a result, many opportunities for exploring various novel variable microfluidic waveguide device with high performance exist across this filed.In this thesis, a detailed review and analysis about the various variable microfluidic waveguide devices has been presented, including the tunable optical waveguide device based on liquid-liquid interface and the tunable optical waveguide device with solid-liquid interface microfluidic. Their advantages and disadvantages about the variable microfluidic waveguide devices had been discussed. Here, several kinds of variable microfluidic waveguide devices with excellent optical performance has been proposed in this thesis, there are microfluidic waveguide attenuator, microfluidic waveguide beam splitter and microfluidic waveguide coupler.A novel scheme for variable optofluidic attenuator is proposed in this thesis, which integrates optical multi-bend waveguide structure and a fluidic channel filled with tunable refractive index liquid. In the first bend of the waveguide, fluidic channel and waveguide form solid-liquid interface. When optical beam is coupled into the port through a tapered fiber coupling, the optical beam propagates along waveguide. With the gradual increase in refractive index of fluid, the original total reflected optical beam is coupled into microfluidic channel. As a result, variable optical attenuator is realized.Then, a novel variable optical splitter is designed, which integrates an asymmetric Y-branch waveguide and a fluidic channel. Above the straight line Y branching waveguide, covered with the fluidic channel. When optical beam is coupled into the port through a tapered fiber coupling, the optical beam propagate at the Y branch will occur reflection and transmission, respectively, and propagate into the left and right branches, with the change in the refractive index of liquid microfluidic channel, the optical power of the beam splitter splitting ratio changed. By cascade, a 1×5 tunable power beam splitter has been designed.Finally, we design a microfluidic waveguide coupler, by using the parallel optical wave coupling theory, and the optical performance of this device has been researched. We design a microfluidic optical modulator based on M-Z interferometer.