基于氧化石墨修饰长周期光纤光栅的传感特性

Sensing characteristics of long period fiber grating functionalized with graphite oxide

提出一种基于氧化石墨烯(GO)修饰的长周期光纤光栅(LPFG)传感器。利用氢氧化钠溶液对LPFG表面进行羟基化处理,采用氢键结合的方式使GO固定在光栅表面,形成基于GO修饰的LPFG传感器。实验研究了GO-LPFG对外部折射率及温度的响应特性,结果表明该GO-LPFG的平均折射率灵敏度较未涂覆GO的LPFG提高1.09倍,温度灵敏度略有降低。随着光栅直径的减小,GO-LPFG的平均折射率灵敏度进一步提高。当光栅直径为108μm时,在折射率1.333~1.448内的平均波长和耦合强度折射率灵敏度分别约为38.99 nm/RIU和57.33 dB/RIU,与未采用GO修饰直径为108μm的LPFG及直径为125μm的GO-LPFG相比,其平均波长和耦合强度折射率灵敏度分别提高1.45,2.17,3.80和3.42倍。该GO-LPFG传感器在各种大分子量的病毒抗原蛋白、生物病菌等生物检测领域具有潜在的应用价值。

A graphene oxide-functionalized long period fiber grating(GO-LPFG)-based fiber optic sensor is proposed.The surface of the LPFG was hydroxylated by sodium hydroxide solution,and GO was fixed on the grating surface by hydrogen bonding to form a GO modification LPFG sensor.The responses of the GO-LPFG to external refractive index and temperature were studied experimentally.The experimental results show that the average refractive index sensitivity of the GO-LPFG is 1.09 times higher than that of uncoated LPFG,and the temperature sensitivity slightly declines.With the decrease of grating diameter,the average refractive index sensitivity of GO-LPFG was further improved.The average wavelength and coupling intensity refractive index sensitivities of the GO-LPFG with a diameter of 108μm in the refractive index range of 1.333-1.448 are^38.99 nm/RIU and^57.33 dB/RIU,respectively.These increased by 1.45,2.17 and 3.80,3.42 times,respectively,compared with those of bare LPFG and GO-LPFG with diameter of 125μm.The proposed GO-LPFG sensor has potential applications in detecting various viral antigen proteins with high molecular weight and biological pathogens in biofields.