Research On Key Technology Of Array Fiber Optic Sensor

Tapered micro nano optical fiber sensor has the advantages of small volume,simple structure,high sensitivity and easy processing.Its application value and importance in the field of biosensor are more and more widely recognized.However,the practical process of micro nano optical fiber sensor faces the problems of mass production and repeatability and stability of the device.In this paper,the high sensitivity,miniaturization and microfluidic chip integration of tapered micro nano fiber are studied,mainly focusing on the consistency of tapered micro nano fiber based on hot stretching and the influence of structural parameters on the excitation mode.At the same time,a design and fabrication method of array sensing chip is given:(1)Based on the fiber mode theory,the refractive index sensing characteristics of wavelength modulated tapered micro nano fiber are studied.By analyzing the relationship between the interference spectrum and the waist length of the fiber,it is found that when the waist diameter of the tapered micro nano fiber is 3?m and the ambient refractive index is about 1.333,the waist length only changes the period of the interference spectrum of HE11 and HE12 modes,and does not affect the sensing sensitivity.(2)The refractive index sensing characteristics of tapered micro nano fiber with different diameters are studied by combining theory with experiment.Especially,the refractive index sensitivity of biochemical fluid with a refractive index similar to water is studied experimentally.Taking NaCl as an example,a tapered micro nano fiber sensing structure with waist diameter of 3.1?m is designed and fabricated.The highest refractive index detection sensitivity of NaCl solution is 92250nm/RIU.At the same time,the difference of sensing characteristics between the taper region and the waist region is studied by droplet scanning experiment,which provides a basis for further miniaturization of the sensor.(3)The relationship between the structure parameters and the excitation mode,the relationship between the stretching speed,the length of the hot zone and the structure,the transmission mode of the micro nano fiber in the manufacturing process are studied.The design,fabrication and packaging of the tapered array micro nano fiber sensing chip are also studied.(4)The performance of the tapered array micro nano fiber sensor chip is tested and the stability of the array sensor chip is verified.The experimental results of tapered micro nano fiber with waist diameter of 3.1?m are analyzed by combining theory with experiment,and the phenomenon that only red shift appears in the output spectrum due to the absorption of sodium chloride solution is explained.