γ辐射对光纤色散的影响

提出了基于能量沉积的辐射对光纤折射率的影响分析方法,计算了光纤的色散变量随光纤的V参数、折射率变化,开展了辐射对光纤色散影响的测量实验,得到了光纤的色散系数随辐射剂量变化数据。实验及理论计算结果表明:(1) 光纤的色散系数随辐射剂量的增加而增大,在一定的剂量(0~500 Gy)范围内,光纤色散增加量呈逐渐饱和趋势;(2) 辐射导致光纤折射率发生变化,从而引起材料色散的变化,辐射效应中的电子密度增大是折射率改变的主要因素;(3) 辐射感生损耗引起的信号幅度降低要比辐射感生色散引起的脉冲展宽明显,对于暴露在核辐射环境中的长距离光纤,其脉冲信号产生的畸变是两者同时存在并共同作用的结果。

Influence of Gamma-ray radiation on optical fiber dispersion

The method based on energy deposition to analyze the influence of -ray radiation on fiber refractive index was proposed. The fiber dispersion variable which changes with the fiber V parameters and refractive index was analyzed and calculated. The radiation effects on fiber dispersion measurement experiments were accomplished, which demonstrates that the radiation impact on the presence of fiber dispersion. The fiber dispersion coefficient variation data with radiation dose were obtained. Experimental and theoretical results show that:(1) fiber dispersion coefficient increases with radiation dose, within the dose range of(0-500 Gy) fiber dispersion coefficient showed a gradual increase in the amount of saturated trends; (2) changes in the refractive index of the fiber lead to the additional material dispersion. The electron density increases caused by radiation is the major factor that results in changes in the refractive index; (3) the decrease of ultra-fast pulsed signal amplitude caused by radiation-induced loss is more significant than pulse broadening caused by radiation-induced dispersion. Both effects exist simultaneously. The pulsed signal distortion is the result of two joint action of especially for long distance optical fiber with nuclear radiation exposure.