Research Of FRET Optofluidic Laser In Fabry-Perot Microcavity

As an important branch of optofluidic devices,optofluidic lasers have been widely used in integrated coherent light sources and biochemical detection of laser signals.Fluorescence resonance energy transfer?FRET?is an energy transfer phenomenon between two fluorescent molecules which are very close to each other.The FRET optofluidic lasers is formed by inserting the fluorescent material which produces FRET into the Fabry-Perot microcavity.The combination of optofluidic lasers and FRET has important research significance,including sensitive biochemical analysis and new photonic devices,such as on-chip coherent light source and bio-tunable lasers.In this paper,firstly,the rate equation of FRET optofluidic lasers based on three-level laser system in FP microcavities is studied,and the theoretical characteristics of the FRET optofluidic laser generation are analyzed in depth.By simulating the emission curves of FRET lasers with different dye concentration of donor and recipient,the threshold conditions of lasing are mastered,which provides a theoretical basis for the experiment of optofluidic lasers.Then the generation of FRET optofluidic lasers in FP microcavities is studied experimentally,which can be divided into the following aspects.1.We used CO₂ laser processing and coating methods combing with the optical microfluidic technique,and fabricated high quality Fabry-Perot?FP?optical microcavity chips.2.Organic dyes coumarin 6?Cou6?and rhodamine 6G?R6G?in solution were used as the gain medium for FRET optofluidic lasers to generate single FRET optofluidic lasers in FP microcavities.3.The mixture of three kinds of organic dyes Coumarin 6?Cou6?,Rhodamine 6G?R6G?and LDS751 in solution were used as the gain media to realize the generation of low-threshold cascaded FRET optofluidic laser.In experiment,a pulse laser with wavelength at 430nm?corresponding to the maximum absorption peak of organic dye Cou6?is used as the pumping source,then a near-infrared optofluidic laser is generated with the laser wavelength corresponding to the emission peak of organic dye LDS 751 by utilizing the resonance energy transfer process between Cou6?donor?and R6G?acceptor?,and the energy transfer process between R6G?donor?and LDS 751?acceptor?,i.e.the two-ordered energy transfer processes.The laser-threshold of optofluidic laser can be dramatically decreased and the corresponding conversion efficiency can be highly improved utilizing the cascaded resonance energy transfer?FRET?of three kinds of organic dyes.Meanwhile the emission of the optofluidic laser can be tuned to a longer wavelength in the case that only one pumping source is supplied.Lastly,The generation of optofluidic laser using quantum dots and organic dyes as gain media in FP microcavity is explored.