摘要
利用镀自组装薄膜的双峰谐振长周期光纤光栅（LPFG）实现了高灵敏的折射率传感,给出了提高镀膜双峰谐振光纤光栅对环境折射率（SRI）灵敏度的途径。确定最佳镀膜厚度,使光纤包层模位于模式转换区附近;调整光纤半径,使镀膜后光栅的双峰位于相位匹配转折点（PMTP）附近,给出了确定最优膜厚和光纤半径的方法。将不同半径的双峰光栅镀自组装聚丙烯胺盐酸盐（PAH）/聚丙烯酸（PAA）薄膜后,放入不同浓度的葡萄糖溶液中进行折射率传感实验。结果表明：通过优化光纤半径和薄膜厚度,镀膜后工作于模式转换区附近和PMTP附近的双峰光栅对1.333-1.372范围内折射率的灵敏度高达3985nm/RIU（RIU为单位折射率）,明显高于不在模式转换区或PMTP附近的光栅,亦高于已报道的非双峰镀膜长周期光纤光栅。
Highly sensitive refractive index sensing is realized by using dual-peak resonance long-period fiber grating（LPFG）with self-assembled coating.The way for improving the sensitivity of coated dual-peak resonance fiber gratings to the surrounding refractive index is given.The fiber cladding mode is located near the mode transition zone by choosing optimal film thickness.The dual-peak structure of fiber coated is located near phase-matching turning point（PMTP）by adjusting the fiber radius.The method for determining optimal film thickness and fiber radius is given.Dual-peak gratings with different fiber radii coated with poly allylaminehydrochliride（PAH）/poly acrylic acid（PAA）films are immersed in different concentrations of glucose solution to carry out refractive index sensing experiments.Results show that the sensitivity of coated dual-peak gratings operating near mode-transition regions and PMTP is 3985nm/RIU in 1.333-1.372 index range,which is obviously higher than those of gratings not operating near mode-transition or PMTP,and also higher than that of non-dual-peak coated LPFGs reported.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2016年第5期122-129,共8页
Chinese Journal of Lasers
基金
国家自然科学基金(60777035)
教育部科学技术研究重点项目(208040)
上海市教育委员会科研项目(07ZZ87)
上海市重点学科建设项目(T0501)
沪江基金(B14004)
关键词
光纤光学
光纤折射率传感
长周期光纤光栅
双峰谐振
模式转换
fiber optics
fiber refractive index sensing
long-period fiber grating
dual-peak resonance
mode transition
