We introduce a wide-field magneto-optical microscope to probe magnetization dynamics with femtosecond temporal and sub-micrometer spatial resolution. We carefully calibrate the non-linear dependency between the magnetization of the sample and the detected light intensity by determining the absolute values of the magneto-optical polarization rotation. With that, an analytical transfer function is defined to directly map the recorded intensity to the corresponding magnetization, which results in significantly reduced acquisition times and relaxed computational requirements. The performance of the instrument is characterized by probing the magnetic all-optical switching dynamics of GdFe in a pump–probe experiment. The high spatial resolution of the microscope allows for accurately subdividing the laser-excited area into different fluence-regions in order to capture the strongly non-linear magnetization dynamics as a function of the optical pump intensity in a single measurement.

中文翻译：

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宽场磁光显微镜以飞秒时间和亚微米空间分辨率获取定量磁化动力学

我们引入了一种宽场磁光显微镜，以飞秒时间和亚微米空间分辨率探测磁化动力学。我们通过确定磁光偏振旋转的绝对值来仔细校准样品的磁化强度与检测到的光强度之间的非线性相关性。有了这个，分析传递函数被定义为直接将记录的强度映射到相应的磁化强度，从而显着减少采集时间并放宽计算要求。该仪器的性能通过在泵-探针实验中探测 GdFe 的磁性全光开关动力学来表征。