将还原氧化石墨烯（rGO）沉积在侧边抛磨光纤（SPF）上制作了一种新型的光纤湿度传感器。在高湿度区域[相对温度(RH)为70%~95%]，传感器的光功率变化达到6.9 dB，尤其在RH 为75%~95%区域，传感器对湿度变化能实现相关系数为98.2%的线性响应，灵敏度可达0.31 dB/(%RH)，响应速度快于0.13 (%RH)/s，并且具有很好的可重复性。对传感机理的理论分析可以解释实验结果，并且表明这种基于石墨烯的光纤传感器亦可广泛应用于其他种类化学气体的探测。这种全新机理的光学传感器是对石墨烯电化学传感器的一种很好的补充，并将促进石墨烯在化学传感技术中的应用。

A novel fiber-optic humidity sensor is fabricated by using a side-polished fiber (SPF) coated with a film of reduced graphene oxide (rGO). The sensor can achieve power variation of up to 6.9 dB in the high humidity range [the relative humidity (RH) is 70% to 95% ], and display linear response with correlation coefficient of 98.2% , sensitivity of 0.31 dB/(%RH), response speed of faster than 0.13 (%RH)/s, and good repeatability in RH from 75% to 95%. Theoretical analysis of sensing mechanism can explain the experimental results, and reveal the broad applying prospect of the sensor for other kinds of chemical vapor detections. Relying on novel sensing mechanism, this graphene-based optical sensor provides a beneficial complement to graphene-based electrical chemical ones, and can promote the employment of graphene in chemical sensing techniques.