利用800nm飞秒激光在未经载氢处理的HI1060光纤中制作了长周期光纤光栅(LPFG)。采用逐线刻写方式实现了谐振波长为1 548.4nm的LPFG,谐振强度为12dB,栅区长度小于4mm。使用不同折射率的氯化钠溶液、蔗糖溶液和酒精溶液分别对LPFG的折射率特性进行了测试和研究。实验中随着三种溶液折射率增加,LPFG的谐振波长发生红移,该LPFG在氯化钠溶液、蔗糖溶液和酒精溶液中的折射率灵敏度分别为175.34、175.31和331.89nm/RIU。实验结果表明,这种基于飞秒激光制作的LPFG对液体折射率变化有较高的灵敏度,可用于液体折射率传感测试。 Long-period fiber gratings (LPFGs) were fabricated in HI1060 fibers without hydrogen treatment using 800 nm femtosecond laser. LPFG with a resonance wavelength of 1 548.4nm was realized by line-by-line engraving, with a resonance strength of 12dB and a gate length of less than 4mm. The refractive index characteristics of LPFG were tested and studied by using sodium chloride solution, sucrose solution and alcohol solution with different refractive indices. In the experiment, as the refractive index of three solutions increased, the resonance wavelength of LPFG shifted red. The refractive index sensitivity of LPFG was 175.34,175.31 and 331.89nm / RIU respectively in sodium chloride solution, sucrose solution and alcohol solution. Experimental results show that LPFG based on femtosecond laser has high sensitivity to the change of liquid refractive index and can be used for liquid refractive index sensing test.