Tu Xinhao, Zeng Yantao, Wang Shibin, Li Linan, Li Chuanwei, Wang Zhiyong
Opt Express. 2022 Dec 19;30(26):46193-46208. doi: 10.1364/OE.468310.
Picosecond ultrasonics (PU), time-domain Brillouin scattering (TDBS), and time-domain thermo-reflectance (TDTR) are all in-situ, non-destructive, and non-contact experimental techniques based on the ultrafast laser pump-probe method, which can generate and detect coherent acoustic phonons (CAP) and thermal transport in thin metal film-glass substrate system. However, these techniques are generally considered different experimental methods to characterize the thermal or mechanical properties of metal nano-objects or transparent materials. Here we present a comprehensive characterization of the generation, propagation, and attenuation of high-frequency CAP and cross-plane thermal transport in the thin Cr film-glass substrate system by PU, TDBS, and TDTR. To investigate the key factors of characterizations, two kinds of thin Cr film-glass substrate systems were measured on the film side and substrate side. The measured thermal and mechanical properties show that boundary conditions and film thickness have significantly affected the characterization.
皮秒超声（PU）、时域布里渊散射（TDBS）和时域热反射（TDTR）都是基于超快激光泵浦 - 探测方法的原位、无损和非接触实验技术，它们可以在金属薄膜 - 玻璃衬底系统中产生并检测相干声子（CAP）和热输运。然而，这些技术通常被认为是用于表征金属纳米物体或透明材料的热或机械性能的不同实验方法。在此，我们通过PU、TDBS和TDTR对Cr薄膜 - 玻璃衬底系统中高频CAP的产生、传播和衰减以及跨平面热输运进行了全面表征。为了研究表征的关键因素，在薄膜侧和衬底侧对两种Cr薄膜 - 玻璃衬底系统进行了测量。测量得到的热性能和机械性能表明，边界条件和薄膜厚度对表征有显著影响。
