三角形大带宽反射光谱光纤光栅的设计和制备

Synthesis and Fabrication of Fiber Bragg Gratings with Triangular and Broad -Bandwidth Reflection Spectrum

反射谱具有三角形形状的光纤光栅在光纤传感等领域中具有重要的应用前景。利用遗传算法设计出了产生三角形光谱分布的光纤光栅的耦合系数沿光纤的分布。计算表明 ,三角形光谱光纤光栅是可以实现的 ,其反射带宽可以通过光栅的啁啾量进行调节 ,常周期的三角光栅反射带宽小 ,变周期的三角光栅反射带宽大 ,其带宽同其啁啾量大致相等。实验中 ,采用光束扫描法制备了反射底宽为 0 .77nm三角形光谱的光纤光栅。

The fiber Bragg gratings with triangular spectrum will have important applications in fiber sensing areas. The coupling coefficient distribution along the length is acquired for triangular spectrum fiber Bragg gratings by using genetic algorithms synthesizing. The simulation results show that the triangular fiber Bragg gratings can be realized; the reflection bandwidth can be adjusted by chirping of the grating; uniform fiber Bragg gratings have small reflection bandwidth, while the gratings with chirped period have larger reflection bandwidth, which is similar to the chirp. A triangular fiber Bragg grating with 0.77 nm base width of reflection spectrum is fabricated experimentally by using a scanning method.