在光纤拼接处刻写长周期光纤光栅及其传感应用

在"单模光纤-细芯光纤"拼接处刻写了 Type Ⅱ 型长周期光纤光栅,构成一种高温光纤传感器.该传感器实际由2 段不同的长周期光纤光栅级联构成,在第二个光栅形成了 Mach-Zehnder 干涉,因此,传感器透射谱由长周期光纤光栅与Mach-Zehnder 干涉仪共同作用形成.利用传感器的透射谱与环境温度的线性变化关系...

Direct writing of long-period fiber gratings on fiber splicing and its sensing applications

A Type II long-period fiber grating is engraved at the splicing of"single mode fiber-thin core fiber"to form a high temperature fiber sensor.The sensor is actually composed of two different long-period fiber grating cascades.The Mach-Zehnder interference in the second grating is formed,so the transmission spectrum of the sensor is formed by the interaction of long-period fiber grating with Mach-Zehnder interferometer.Using the linear variation relationship between the transmission spectrum of sensor and the ambient temperature,the ambient temperature is measured.Two resonant peak trough dip 1 and dip 2 of the sensor transmission spectrum are selected to measure the external temperature change.The experimental results show that the temperature sensitivity of the dip 1 is 103.4 pm/℃and the temperature sensitivity of the dip 2 is 121.8 pm/℃in the measuring range of 300℃~800℃,and the maximum measuring temperature can reach 800℃.The sensor is simple and easy to repeat,with high sensitivity,good linearity and low cost.It has certain application value in the field of high temperature sensing.