应用800nm飞秒激光制备长周期光纤光栅

Inscription of long period fiber gratings using 800 nm femtosecond laser

利用800nm钛蓝宝石飞秒激光器制备了长周期光纤光栅,并实验验证了长周期光纤光栅的高温特性。基于摄像头和电动位移平台设计了激光精确对准光纤纤芯的方案;以计算机控制1.3mW飞秒激光,使用逐点曝光法在未经载氢处理的光纤上刻写了长周期光纤光栅,实验显示该光栅在1 200～1 700nm波段的主谐振峰值可达-17dB。利用高温箱对长周期光纤光栅进行高温传感特性实验,在300～800℃得到的主谐振峰温度响应灵敏度为0.056nm/℃,线性度为0.992。实验结果表明,提出的以800nm钛蓝宝石飞秒激光器制备长周期光纤光栅的方法稳定可靠,写制的光栅在高温环境下变化均匀,不易退化,响应特性良好,适用于高温检测。

Long Period Fiber Gratings（LPFGs） were inscribed by using a 800 nm femtosecond laser and their high-temperature properties were verified in this paper.Firstly,an inscription system for the laser into fiber cores was designed using a camera and an electric moving platform.With controlling a pulse laser of 1.3 mW,a LPFG was inscribed in a non-hydrogen-loaded bare fiber using point by point technique,and the resonant peak of the LPFG is about-17 dB in the 1 200~1 700 nm band.Then,high temperature sensing experiments were performed on the LPFG by a high temperature box,obtained results show that the linearity of the resonance peak changes is about 0.992 and temperature sensitivity is 0.056 nm/℃ at 300-800 ℃.It demonstrates that the inscription technology for LPFGs by using the 800 nm femtosecond laser is feasible and obtained LPFGs have good response characteristics and stability,and are suitable for the high-temperature measurement.