利用光线追迹法, 研究了典型光纤拉曼探头在纳米结构损伤限制下收集到的表面增强拉曼散射(SERS)功率与样品位置之间的关系。 结果表明, 对于不同焦距构成的同轴等光程光纤拉曼探头, 在给定的纳米结构损伤阈值激发光功率密度下, 样品偏离焦平面反而会使探头收集到的SERS功率增加, 相比于样品远离探头方向偏离焦平面, 靠近探头方向 偏离焦平面时收集到的SERS功率更高。此外, 收集光纤芯径越大, 探头所收集的SERS功率越大。

The relationship between surface-enhanced Raman scattering (SERS) power collected by the fiber Raman probe and sample position was investigated theoretically under the sample damage threshold limit by using ray tracing method. The results show that, in a given damage excitation power density threshold, the SERS power collected by the probe with different focal-length lens increases when the sample deviates from the focal plane. Furthermore, compared with the situation that the sample is away from the probe and deviate from the focal plane, SERS power collected by the probe is higher at the situation that the sample is close to the probe and deviates from the focal plane. In addition, the lager the collection fiber core diameter is, the greater the power collected by the probe will be.