A fiber‐optic setup incorporating the pump‐probe thermoreflectance (TR) technique with Fabry–Perot (FP) interferometer is presented. It includes both heat pump and probe lasers, producing wavelengths of 1470 and 1530 nm, respectively, together with a reflected radiation detector. Heat pump pulse duration varies from a few microseconds to tens of microseconds. The potential of the pump‐probe TR‐FP technique to investigate the subsurface region of semiconductors with a range of electron spectra is demonstrated. A pronounced dip in time dependence of the TR‐FP signal is discovered at the liquid nitrogen temperature in the gapless semiconductor compound HgSe—a candidate for the family of Weyl semimetals with broken inversion symmetry. This finding implies the developed pulsed TR‐FP method for the detection of Weyl nodes and surface Fermi arcs in solids.

中文翻译：

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用于表征固体近表面层的激光泵浦光纤技术：研究半导体和Weyl半金属的开发和应用前景

提出了一种将泵浦探针热反射（TR）技术与Fabry-Perot（FP）干涉仪结合在一起的光纤装置。它包括热泵激光器和探测激光器，分别产生1470和1530 nm的波长，以及反射辐射探测器。热泵脉冲的持续时间从几微秒到几十微秒不等。展示了泵浦探针TR-FP技术研究具有一定电子光谱范围的半导体表面区域的潜力。在无间隙半导体化合物HgSe中找到液氮温度下TR-FP信号在时间上有明显的时间依赖性，该化合物是具有颠倒对称性的Weyl半金属族的候选者。