Microstructured Fiber Optofluidic Laser And Its Applications For Sensing

The fiber optofluidic lasers integrate optical microcavities,gain medium and microfluidic channels.The circular cross section of the fiber supports whispering gallery mode(WGM),combining the advantages of lasers and microfluidics.The fiber optofluidic lasers provide a low-cost and sensitive detection platform with high repeatability and broad dynamic range,which makes it irreplaceable in the field of biochemical sensing.The solid quartz core of the traditional communication fiber limits the use of its internal space and hinders its further integration.In this paper,the purpose of integrating the gain medium and the microfluidic channel into the same fiber was realized through the processing of microstructured fiber,which reduced the volume of the device.This article finished the following:(1)A hollow fiber microlaser based on a dye-doped polymer film was prepared.A polymer(PS-PMMA)film doped with a fluorescent dye(Rhodamine 640,Rh640)was coated on the inner wall of a single-hole hollow fiber with an outer diameter of 103.9?m and a wall thickness of 11.7?m by solvent evaporation deposition,and successfully achieved output the laser with a threshold of 1.7?J/mm~2;(2)A laser output of a larger wavelength range was realized for the above micro laser.The Rh640 doped in the polymer film was replaced by R6G and RhB.The laser output in different wavelength ranges was successfully realized by replacing the fluorescent dye species.The thresholds were 4.14?J/mm~2 and 3.77?J/mm~2,respectively;(3)The above microlaser was optimized and realized the refractive index sensing of the bulk solution.Based on the single-hole thin-wall hollow fiber with an outer diameter of 133?m and a wall thickness of 3.87?m,the above micro-laser was optimized and improved,the threshold was reduced to 0.92?J/mm~2,and the refractive index sensing of sodium chloride solution was successfully realized based on wavelength drift,and the sensing sensitivity was 139.44 nm/RIU;(4)The manufacturing method of the microfluidic sensor were designed based on the dual-hole fiber microlaser.The laser output was realized with a 2mM R6G ethanol solution by chemical etching,and the threshold was 2.05?J/mm~2.Finally,in this paper,a method microstructure processing by the femtosecond laser was designed and a dual-hole fiber optofluidic laser sensor was constructed,which provides the possibility of biosensing in the future.