对普通载氢光纤光致折射率变化量与曝光时间的关系进行了实验测量研究。针对不同曝光时间导致的光栅强度不同, 分别提出了均匀光栅最大反射率测量模型和反射率零点带宽测量模型, 并分析了两个模型由于布拉格反射波长的测量误差对光致折射率变化量计算结果造成的影响。结果表明, 244 nm氩离子倍频激光器输出光功率为40 mW时, 普通载氢光纤光致折射率变化量随曝光时间总体上呈现指数分布关系Ac=1.632×10-6 t 0.76912; 在曝光时间较短时, 造成的光栅强度较弱, 光致折射率变化量有明显的指数增长趋势, 之后是一段较好的线性区域, 这时两个测量模型的结果得到了很好的印证, 随着曝光时间的继续增加, 光致折射率变化量达到饱和。

The relationship between UV photo-induce index changes of single mode hydrogen loading fiber and its dose is studied experimentally. Maximum reflectivity model and reflectivity notch bandwidth model of uniform grating are proposed respectively for different fiber grating strength caused by its dose and the influence on AC result of Bragg reflectivity wavelength deviation are analyzed relatively. Results based on experiment and measurement data indicate that, when 244 nm argon ion laser emits 40 mW UV light, the curve of refractive index changes in single mode hydrogen loading fiber is exponential type (Ac=1.632×10-6 t 0.76912), exponential growth is obvious in the beginning, a very good linear region is following, and then refractive index increments reach saturated.