将非高斯加热光束引入到模式不匹配的脉冲热透镜技术中,描述了非高斯加热光束热透镜技术的优点。实验研究了不同加热光束形状时热透镜信号的振幅和时间特性以及与实验参数的关系。实验结果显示在不同加热光束形状时都可通过使用近场探测构型和优化实验参数如探测距离提高热透镜技术的测量灵敏度,而通过使用远场探测构型则可消除实验参数对材料热性质测量的影响。

A non-Gaussian beam excitation scheme was introduced to a mode-dismatched pulsed thermal lens technique. The advantages of the thermal lens approach with a non-Gaussian beam excitation were described. Experiment was performed to investigate the amplitude and temporal behaviors of the thermal lens signals excited by non-Gaussian beams of different profiles, as well as their dependences on the experimental parameters. The experimental results showed that for different beam profiles, the measurement sensitivity of the thermal lens technique could be maximized by employing the near-field detection scheme and optimizing the geometric parameters (e.g., the detection distance) of the thermal lens configuration. On the other hand, the influence of these geometric parameters on the determination of thermal properties of a measured sample could be minimized by using a far-field detection scheme.