Research On Fabrication And Characterization Of Fiber Micro-structure Devices

With the development of fiber sensing,integration,all-optical fiber,micromation and multi-parameter measurement are main directions for fiber optic sensor.In this thesis,the integrated optical fiber microstructure sensors with different functional characteristics are fabricated by using the excimer laser micromachining technique.Based on the fabrication and application of current fiber Fabry-Perot sensor and laser micro-fabrication technology,the processing and production of micron size micro-hole is realized on ordinary single mode fiber by optimizing the parameters of 193 nm excimer laser processing system.In order to meet the need of sensing function,several fiber microstructure sensors with different micro-holes structures are designed,and their structures are optimized then.Not only the effects of structural parameters on the transmission spectrum characteristics are studied,but also the response characteristics of the sensors to environmental refractive index and temperature are analyzed in detail.The following are the main content and conclusions.?1?A kind of single micro-hole FPI sensor is proposed,and the temperature sensing characteristic is investigated theoretically and experimentally.The result show that the relationship between wavelength shift and temperature change has better linearity in temperature range of 30-85?.The temperature sensitivity of single micro-hole FPI sensor is0.160 nm/? and the linearity is 0.994.?2?A kind of dual micro-holes FPI sensor is proposed.According to theoretical analysis,the multi-cavities of sensor can be simplified to two FP cavities.Two sensors with different distance between micro-holes are fabricated,and the temperature sensing characteristics of them are investigated theoretically and experimentally.When the distance between micro-holes is 1 mm,the temperature sensitivities of two FPIs are-0.176 nm/? and-0.156nm/?,respectively.When the distance between micro-holes is 2 mm,the temperature sensitivities of two FPIs are-0.190 nm/? and-0.188 nm/?,respectively.?3?A kind of integrated FPI-FBG composite fiber sensor is proposed.The wavelength response characteristics of FPI and FBG during the process of heating and cooling in temperature range of 100-500? are experimentally investigated.Furthermore,an integrated FPI-FBG composite fiber sensor which can simultaneously measure temperature and RI is fabricated.The sensitivities of temperature and RI for FPI are-0.189 nm/? and 1210.490nm/RIU,respectively.The temperature sensitivity for FBG is 0.011 nm/?,and the FBG is insensitive to RI.The temperature and RI resolutions of integrated FPI-FBG composite fiber sensor are 0.1? and 1.5×10^5-RIU,respectively.?4?A kind of dual FPI-FBG composite fiber sensor is proposed.According to theoretical analysis of dual micro-holes FPI sensor,the multi-cavities of sensor can be simplified to the integration of two FPIs and FBG.The temperature sensitivities for two FPIs are-0.175 nm/? and-0.165 nm/?,respectively.The RI sensitivities for two FPIs are 1128.190 nm/RIU and1120.799 nm/RIU,respectively.The sensitivities for FBG are 0.011 nm/? and 5.044 nm/RIU,respectively.The temperature and RI resolutions of dual FP-FBG composite fiber sensor are0.1? and1.0×10^-5RIU,respectively.The micro-holes fiber sensors which are fabricated by exicimer laser have advantages of compact structure,simple production,high integration,sensitivity and linearity,which provide a new idea for the integration of interferometric sensor.