Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution.
Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution.
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DOI：
10.1063/1.4842276
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发表时间：
2013-10
期刊：
影响因子：
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通讯作者：
T. Henn;T. Kießling;W. Ossau;L. Molenkamp;K. Biermann;P. Santos
中科院分区：
文献类型：
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作者：
T. Henn;T. Kießling;W. Ossau;L. Molenkamp;K. Biermann;P. Santos
我们描述了一种双色泵浦-探测扫描磁光克尔效应显微镜，我们已经发展到研究电子自旋现象在半导体在低温下与皮秒时间和微米空间分辨率。我们的显微镜的关键创新是使用超快“白色光”超连续光纤激光源，可提供整个可见光和近红外光谱范围。我们的克尔显微镜允许独立选择激发和检测能量，同时避免了同步两个单独的皮秒激光系统的脉冲序列的必要性。独立调谐泵浦和探测波长的能力使得能够研究激发能量对光诱导电子自旋动力学的影响。我们演示了皮秒实空间成像的光激发电子自旋包在（110）GaAs量子阱样品的扩散膨胀，以说明仪器的能力。
We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast "white light" supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.