Wang Zhongyu, Min Jing, Sun Yong, Wang Xuesong, Chen Xiuguo, Tang Zirong, Liu Shiyuan
School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Optics Valley Laboratory, Wuhan 430074, China.
Photoacoustics. 2024 Dec 11;41:100678. doi: 10.1016/j.pacs.2024.100678. eCollection 2025 Feb.
Femtosecond photoacoustic detection is a powerful all-optical technique for characterizing metal nanofilms. However, the lack of accurate descriptions of the temperature-dependent optical properties of metal nanofilms during ultrafast thermal processes hinders the deep understanding of this dynamic behavior, leading to compromised measurement accuracy. To address this, we developed Critical Point Models (CPMs) for copper and AlCu nanofilms to describe their dynamic optical properties during photoacoustic testing. By integrating dynamic behavior into ultrafast laser-matter interaction and acousto-optic processes, we explored the temperature effects throughout testing. Numerical simulations were performed to analyze the temperature, stress, and surface reflectivity distributions of the nanofilms. Compared to experimental results, our dynamic models significantly improved prediction accuracy for both copper and AlCu nanofilms. This highlights the importance of temperature dependence in femtosecond photoacoustic testing and validates our model's capability to capture the behavior of metal nanofilms under ultrafast laser irradiation.
飞秒光声检测是一种用于表征金属纳米薄膜的强大全光学技术。然而，在超快热过程中缺乏对金属纳米薄膜温度相关光学特性的准确描述，阻碍了对这种动态行为的深入理解，导致测量精度受损。为了解决这个问题，我们开发了铜和铝铜纳米薄膜的临界点模型（CPM），以描述它们在光声测试过程中的动态光学特性。通过将动态行为整合到超快激光与物质相互作用和声光过程中，我们在整个测试过程中探索了温度效应。进行了数值模拟，以分析纳米薄膜的温度、应力和表面反射率分布。与实验结果相比，我们的动态模型显著提高了铜和铝铜纳米薄膜的预测精度。这突出了飞秒光声测试中温度依赖性的重要性，并验证了我们的模型捕捉超快激光辐照下金属纳米薄膜行为的能力。
