Lourens D G, Kwaaitaal M, Davies C S, Kirilyuk A
FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
Rev Sci Instrum. 2025 Jul 1;96(7). doi: 10.1063/5.0266905.
Research into ultrafast dynamic processes in solids is crucial for understanding the intrinsic properties of matter. In particular, the combination of temporal and spatial resolution provides the most valuable information on such processes. Here, we demonstrate a setup for time-resolved imaging of ferroelectric domain dynamics following excitation by infrared pulses from a free-electron laser. The contrast in full-field imaging was provided by optical second harmonic generation produced with a femtosecond laser, which allowed us to identify both 90° and 180° domains and observe the induced switching of 180° domains in barium titanate. Moreover, the dynamics of crystallographic strains resulting from the excitation could be directly visualized across sub-picosecond timescales.
对固体中超快动态过程的研究对于理解物质的内在性质至关重要。特别是，时间和空间分辨率的结合为这类过程提供了最有价值的信息。在此，我们展示了一种用于对自由电子激光发出的红外脉冲激发后的铁电畴动力学进行时间分辨成像的装置。全场成像中的对比度由飞秒激光产生的光学二次谐波提供，这使我们能够识别90°和180°畴，并观察钛酸钡中180°畴的诱导开关。此外，激发产生的晶体应变动力学可以在亚皮秒时间尺度上直接可视化。
