基于双延迟工作台的泵浦-探测光测量技术的改进(英文)

Improvement of pump-probe optical measurement technique using double moving stages

为了提高飞秒激光瞬态热反射测量技术的测量精度并增加测试的可靠性,延长了泵浦光和探测光的相对光程差,以提高实验数据与理论模型间的拟合精度.通过在泵浦光路中放置一个和探测光路中同样的机械位移平台,搭建了一个新的测试实验台,将两光束的光程差由4 ns提高到8 ns.测量结果表明,当后4ns的测量数据与前4 ns的数据平滑连接后,泵浦光和探测光束间由于发散和飘移所引起的测量误差可忽略不计.对Al/Si和Cr/Si样品界面热导的测量结果表明,实验测得值和现有文献报道数据非常吻合,证实了改进系统的可靠性.

In order to improve the measurement precision and increase the reliability of the femtosecond laser transient thermoreflectance system, the relative optical path difference between pump and probe beams is prolonged, which can improve the fitting accuracy of the experimental data to the theoretical model. A modified experimental setup is devised with the pump path intercalated a moving stage identical to the one in the probe path, which extends the optical path difference of the probe beam relative to the pump beam from 4 to 8 ns. The measured results indicate that the uncertainty from the misalignment and divergence of both beams can be ignored when the last 4 ns experimental data are connected with those of the first 4 ns smoothly. The as-obtained thermal conductance of AI/Si and Cr/Si interfaces agrees well with the reported experimental values, which verifies the reliability of this modified version of this measurement.