基于耦合模理论利用传输矩阵法研究级联长周期光纤光栅(Cascaded Long Period Fiber Gratings, CLPG)的光谱特性。结果表明:选用两个参数相近的长周期光纤光栅(Long Period Fiber Gratings, LPG)级联可以获得更明显的透射谱。周期的增...基于耦合模理论利用传输矩阵法研究级联长周期光纤光栅(Cascaded Long Period Fiber Gratings, CLPG)的光谱特性。结果表明:选用两个参数相近的长周期光纤光栅(Long Period Fiber Gratings, LPG)级联可以获得更明显的透射谱。周期的增加导致损耗峰向长波方向线性漂移,可据此实现对特定波长的损耗。长度和折射率调制深度主要影响损耗峰深度,可以用于调控损耗峰出现极深值点。得到当两个级联LPG的周期为500 μm、长度为3 cm,折射率调制深度为0.00014时存在窄而深的最优CLPG损耗峰。该研究结论为分析级联长周期光纤光栅理论和改进传感器件设计应用提供了依据。展开更多
从耦合模理论出发,运用传输矩阵法对级联长周期光纤光栅(CLPG)的传输光谱进行了仿真分析,提出了基于CLPG的分布式光纤布拉格光栅(FBG)解调系统。该解调系统将级联长周期FBG作为边缘滤波器,利用它的4个线性区同时解调4个FBG的传感信号。...从耦合模理论出发,运用传输矩阵法对级联长周期光纤光栅(CLPG)的传输光谱进行了仿真分析,提出了基于CLPG的分布式光纤布拉格光栅(FBG)解调系统。该解调系统将级联长周期FBG作为边缘滤波器,利用它的4个线性区同时解调4个FBG的传感信号。仿真结果表明:在CLPG的线性范围内系统检测的光功率与传感FBG所受轴向应变成线性关系,最高能检测到5.813×10-9的轴向应变传感信号。系统的应变灵敏度分别为-42.75,42.95,-43.15,43.35 m W/10-6。展开更多
An optical fiber magnetic field sensor for the dual-parameter simultaneous measurement is proposed and demonstrated. The sensor head is constructed by a peanut-shape structure and long period fiber grating(LPFG) coate...An optical fiber magnetic field sensor for the dual-parameter simultaneous measurement is proposed and demonstrated. The sensor head is constructed by a peanut-shape structure and long period fiber grating(LPFG) coated by magnetic fluid(MF). The external magnetic field intensity can be measured by the variation of characteristic wavelength(Dip1 and Dip2) in interference spectrum since the effective refractive index of MF changes with external magnetic field intensity. When the external magnetic field intensity changes from 0 mT to 20 mT, the magnetic field sensitivities of Dip1 and Dip2 are -0.064 nm/mT and -0.041 nm/mT, respectively. Experimental results show that the temperature sensitivities of the Dip1 and Dip2 are 0.233 nm/℃ and 0.186 nm/°C, respectively. Therefore, the simultaneous measurement of the magnetic field intensity and temperature is demonstrated based on the sensitive matrix. It has some potential applications in aerospace, environmental monitoring and medical sensing fields.展开更多
文摘基于耦合模理论利用传输矩阵法研究级联长周期光纤光栅(Cascaded Long Period Fiber Gratings, CLPG)的光谱特性。结果表明:选用两个参数相近的长周期光纤光栅(Long Period Fiber Gratings, LPG)级联可以获得更明显的透射谱。周期的增加导致损耗峰向长波方向线性漂移,可据此实现对特定波长的损耗。长度和折射率调制深度主要影响损耗峰深度,可以用于调控损耗峰出现极深值点。得到当两个级联LPG的周期为500 μm、长度为3 cm,折射率调制深度为0.00014时存在窄而深的最优CLPG损耗峰。该研究结论为分析级联长周期光纤光栅理论和改进传感器件设计应用提供了依据。
文摘从耦合模理论出发,运用传输矩阵法对级联长周期光纤光栅(CLPG)的传输光谱进行了仿真分析,提出了基于CLPG的分布式光纤布拉格光栅(FBG)解调系统。该解调系统将级联长周期FBG作为边缘滤波器,利用它的4个线性区同时解调4个FBG的传感信号。仿真结果表明:在CLPG的线性范围内系统检测的光功率与传感FBG所受轴向应变成线性关系,最高能检测到5.813×10-9的轴向应变传感信号。系统的应变灵敏度分别为-42.75,42.95,-43.15,43.35 m W/10-6。
基金supported by the National High Technology Research and Development Program of China(863 Program)(No.2013AA014200)the National Natural Science Foundation of China(No.11444001)the Municipal Natural Science Foundation of Tianjin(No.14JCYBJC16500)
文摘An optical fiber magnetic field sensor for the dual-parameter simultaneous measurement is proposed and demonstrated. The sensor head is constructed by a peanut-shape structure and long period fiber grating(LPFG) coated by magnetic fluid(MF). The external magnetic field intensity can be measured by the variation of characteristic wavelength(Dip1 and Dip2) in interference spectrum since the effective refractive index of MF changes with external magnetic field intensity. When the external magnetic field intensity changes from 0 mT to 20 mT, the magnetic field sensitivities of Dip1 and Dip2 are -0.064 nm/mT and -0.041 nm/mT, respectively. Experimental results show that the temperature sensitivities of the Dip1 and Dip2 are 0.233 nm/℃ and 0.186 nm/°C, respectively. Therefore, the simultaneous measurement of the magnetic field intensity and temperature is demonstrated based on the sensitive matrix. It has some potential applications in aerospace, environmental monitoring and medical sensing fields.
