The Research Of Microfluidic Dye Lasers And Optofluidic Devices

Optofluidics is defined as the marriage of optics and microfluidics, which fundamentally aims at the merge of optics and microfluidics at micro-scale to create versatile devices and systems. In this dissertation, polydimethylsiloxane(PDMS) based optofluidic dye lasers and laminar flow as well as microdroplet based optofluidic devices are mainly concerned.With the development of micro total analysis systems, integrated photonic laser sources with small volume sizes and low consumptions are of great importance in bio-chemical and bio-sensing analysis. In addition, the miniaturization of photonics systems makes the integrated laser source an essential part for lab-on-a-chip systems. We demonstrate an optofluidic microring resonator dye laser which is developed by traditional soft lithography and PDMS rapid prototype techniques. By the improvement of microcavity construction design, the loss of the optical resonance cavity has been largely reduced and thus resulted in the reduction of the lasing threshold.Compared with conventional optofluidic dye laser which inevitably requires optical resonance microcavity to provide optical feedback, we introduce a low threshold optofluidic random laser which further simplifies the fabrication process by getting rid of the soft lithography procedures. Nanoscale wrinkles are formed on the oxidized surface of a PDMS slab. Light multiply scattered at each PDMS wrinkle-dye interface is optically amplified in the presence of pump gain.Contrast to traditional rigid solid optical devices, optofluidic elements show unique abilities such as high integration and reconfiguration. The properties of the optofluidic devices can be tuned by different interaction between liquids. We fabricated a double-arm optical interference microfluidic chip and have done simulation about different refractive index distribution in the microchannel owing to different flow velocity contrast ratio between two injection liquids. In experiment, the resonance peak positions as well as the peak numbers of the interference spectrum changes under different kinds of flow ratio. By adjusting the flow velocities of the two liquids in the microchannel, an integrated tunable interferometer was established due to the optical path differences controlled by diffusion.Droplet microfluidics is defined as manipulating microdroplets to precisely control their formation, reaction and mixing in a microchannel. Breakup of the two immiscible liquids at the T-junction produces a droplet. The size and content of the droplet can be determined by the reflection signal at the PDMS-liquid interface. Meanwhile, we also introduce an optofluidic signal generator based on the microfluidic droplet gratings. Both triangle and rectangle signals with different frequencies are accomplished by varying the flow rates of the liquids.