Refractive Index Measurement And Continuous-Wave Pump Testing Of Optofluidic Laser Based On FP Microcavity

Otofluidic microfluidics mainly integrates optofluidic devices into the microfluidic chip,and can improve the portability and functional integration of the microfluidic analysis system.The light microfluidic laser uses the organic dye dissolved in the liquid as the gain medium,and the optofluidic microcavity is used as the resonant cavity generated laser.At the same time,It has important applications in miniaturized coherent light sources and biochemical sensing detection based on laser signals.In biochemical sensing applications,this paper studies a liquid refractive index measurement method based on light microfluidic single-mode lasers.Firstly,a high-Q Fabry-Perot?FP?optofluidic microcavity was prepared.The gain medium used was an alcohol-soluble organic dye solution,Rhodamine 6G,which was obtained under the action of external pump light.The generation of a light micro-flow single-mode laser has a full-width at half maximum of 0.260nm.Subsequently,the generation of single-mode lasers in different mixture solvents?absolute ethanol and deionized water?with water contents of 1.09,5.98,11.91,20.42,30.75,45.27,and 51.89 mol%was realized,and the wavelength was found to increase with the water content.Moving toward the long wavelength direction,when the water content exceeds 45.27 mol%,the center wavelength of the single-mode laser starts to move toward the short wavelength direction,i.e.,a blue shift phenomenon.And according to the movement of single-mode laser wavelength to achieve the measurement of the refractive index of the sample solution.The experimental results and analysis showed that the minimum measurable refractive index change was 6.31×10^-4,the measurement sensitivity was 411 nm/RIU,and the measurement results and errors were analyzed.The optofluidic microfluidic laser chip detection technology converts the fluorescence signal emitted by the gain medium into a laser signal by adding an optofluidic resonant cavity to the microfluidic chip so as to amplify the detection signal;compared with the fluorescence detection technology,the technology uses a laser.as a sensor signal,it has a higher detection sensitivity and a larger signal-to-noise ratio.In order to promote the integration,practicality and portability of optofluidic microchip detection technology,this work further uses continuous laser as the pumping light source of optofluidic microfluidic lasers to explore the generation of continuous optically pumped microchip lasers.The theory of continuous optofluidic pumping is theoretically and experimentally analyzed.We focus on theoretical analysis and experimental improvement of the flow velocity,pump spot size,and Q value of the FP cavity in the microfluidic channel.Finally,the experimental results are analyzed in detail.And propose the next steps to improve measures.