利用单个侧边抛磨光纤光栅传感器上形成的双布拉格反射峰,进行微量液体材料在光波长为1550 nm处的热光特性研究。通过测量得到传感器双反射峰波长差与覆盖聚合物材料折射率间的对应关系以及光纤传感器覆盖某待测液体时双反射峰波长差与温度的对应关系,对这两个对应关系进行分析,得到了美国Cargille Lab公司的三种聚合物液在光波长为1550 nm处的热光系数。该光纤传感器可用于分析折射率处于1.4198~1.4479液体材料的热光特性。
Thermo-optic effect of liquid materials at optical wavelength of 1550 nm is investigated by use of a side polished fiber Bragg grating(FBG) sensor with double reflective Bragg wavelengths.The relationship between the difference of double reflective Bragg wavelengths of sensor and refractive index of overlaid liquid material is measured,and the relationship between the difference of double reflective Bragg wavelengths and temperature is measured when a liquid material overlays on the polished region of sensor.By analysis of the relationships above the thermo-optic coefficients of three liquids made by Cargille Lab are obtained at optical wavelength of 1550 nm.The fiber sensor could be used for measurement of thermo-optic characteristic of liquid materials as their refractive indexes are in the range of 1.4198~1.4479.