基于光纤布拉格光栅与长周期光栅并联的集成光学传感器

摘要

In order to improve the performance of the fiber optic sensors and further reduce the size of them,a new integrated optical sensor based on a fiber Bragg grating (FBG)in parallel with a long-period grating (LPG)in a single mode fiber is reported in this paper.The FBG and the LPG are fabricated by femtosecond laser using direct inscription process.The variations of temperature and refractive index will cause the varia-tions of resonant wavelengths of FBG and LPG.The experimental results show that the refractive index sensi-tivities of the FBG and the LPG respectively are 0 nm /RIU and 196.46 nm /RIU,and the temperature sensi-tivities of them are 12.98 pm /℃ and 10.93 pm /℃ respectively.Therefore,this sensor can be used for meas-uring temperature and refractive index simultaneously according to the dual parameters sensing matrix.%为了提高光纤传感器的性能和进一步缩小传感器的尺寸，通过实验制备出一种基于光纤布拉格光栅（FBG）与长周期光栅（LPG）并联的新型集成光学传感器。该传感器中的 FBG 和 LPG 是利用飞秒激光直写技术直接在普通单模光纤中刻写的。FBG 和 LPG 是并联关系，因此很大程度地缩小了传感器的长度。外界的温度和折射率的变化会引起 FBG 和LPG 的谐振峰波长位置发生变化，据此对该集成传感器进行温度和折射率测量。实验结果表明：FBG 谐振峰对折射率和温度的灵敏度分别为0 nm／RIU 和12．98 pm／℃，而 LPG 在1555 nm 附近谐振峰对折射率和温度的灵敏度为196．46 nm／RIU 和10．93 pm／℃。因此，根据双参数传感矩阵，该传感器可以对温度和外界折射率进行同时传感。