基于飞秒激光的光纤三维微结构制备研究

为适应新型光纤传感器件的需要,进行了飞秒激光在石英光纤材料上制备三维微结构的工艺探讨。实验结果表明,光纤的烧蚀阈值约为1.5 J/cm2,烧蚀孔的深度与能量对数基本上符合线性关系。在一定条件下,适当的增加激光能量有利于改善微孔的垂直度。理论分析了锥孔和直孔的成形机理,探讨了微孔内壁形貌的形成机制和加工过程中光纤背面出现的崩碎现象。采用适当的加工工艺,试制了光纤F-P腔、光纤端部悬臂梁等三维微结构。

Study on fabrication of fiber 3D microstructures based on femtosecond laser

To meet the needs for new fiber optic sensors,the process for fabricating 3D microstructures in silica fiber materials by femtosecond laser is discussed.Experimental results show that the ablation threshold of fiber is about 1.5 J/cm2;the ablation depth is of approximately linear relation with the laser energy.Under some conditions,the higher energy is more beneficial to the formation of upright hole.The formation mechanisms of taper hole,upright hole and their surface morphology are discussed.The disintegration appeared on the back surface of the optic fiber is analyzed.Some three-dimensional microstructures were fabricated on the fiber end,such as F-P cavity,cantilever structure,etc.