Highly Sensitive Humidity Sensor Based on Ultra-long-Period Fiber Gratings with Asymmetric Refractive Indez Modulation

摘要：

An Ultra-long-period fiber grating (ULPFG) with asymmetric refractive index modulation is fabricated in standard telecommunication optical fiber by using high-frequency CO2 laser pulses. A highly sensitive humidity sensor based on this grating can be realized due to its high refractive index sensitivity. The ULPFG is coated with a new nano-composite hydrogel material that has a strong water absorption capacity. This kind of hydrogel can absorb water vapor in the air substantially to make its own refractive index change, inducing the resonant peak shift of the ULPFG to realize the humidity measurement. The experimental results show that a resonant peak shift of～30nm corresponding to a variation of the surrounding humidity in the range of 38％~96％, which is three times higher than that of the humidity sensors reported. Such a novel humidity sensor could find important applications in humidity measurement.

关键词： optical fiber sensors long-period fiber grating hydrogel humidity sensor

作者: Y. Song T. Zhu Y. J. Rao Y. W. Zhao

作者单位: Key Lab of Optoelectronic Technology & Systems (Education Ministry of China),Chongqing University, C Key Lab of Optoelectronic Technology & Systems (Education Ministry of China),Chongqing University, C Key Lab of Optoelectronic Technology & Systems (Education Ministry of China), Chongqing University,

会议类型: 国际会议

会议名称: 第五届仪器科学与技术国际学术会议(ISIST 2008)Fifth International Symposium on Instrmentation Science and Technology

会议地点: 沈阳

会议语种:英文

页码: 1-4

在线出版日期: 2008-09-15（万方平台首次上网日期，不代表论文的发表时间）