少模光纤光栅的飞秒激光制备及其特性

Few modes FBG inscribed by femtosecond laser and its characteristics

利用飞秒激光和相位掩模法在少模光纤中成功制备了光纤布拉格光栅(FBG),并对其反射光谱特性和高温应变传感特性进行了研究。结果表明:少模FBG的反射光谱中具有3个主反射峰,分别对应不同模式的自耦合和模式之间的互耦合。该FBG在800℃以下具有很好的温度响应特性,温度灵敏度为14. 27 pm/℃,且在500℃时具有很好的应变响应特性,应变灵敏度为1. 77 pm/10-6。其有望在高温应变传感和多波长光纤激光器方面得到一定的应用。

Fiber Bragg gratings(FBG)are successfully fabricated in few mode fiber using femtosecond laser and phase mask technique,its reflection spectrum,high temperature and strain sensing characteristics are studied.The results show that there are three main reflection peaks in the reflection spectrum of few modes FBG,which correspond to the self-coupling and the mutual coupling between different modes.This FBG has very good temperature response characteristics under 800℃,and the temperature sensitivity is 14.27 pm/℃.It also has very good strain response characteristics at 500℃,and the strain sensitivity is 1.77 pm/10-6.It can be potentially used in strain sensing under high temperature and multiwavelength fiber laser.