• DOI:10.1088/1367-2630/ABB54B
• Corpus ID: 215238553

Quasi-nondegenerate pump–probe magnetooptical experiment in GaAs/AlGaAs heterostructure based on spectral filtration

@article{Surnek2020QuasinondegeneratePM,
  title={Quasi-nondegenerate pump–probe magnetooptical experiment in GaAs/AlGaAs heterostructure based on spectral filtration},
  author={M. Sur{\'y}nek and Luk{\'a}{\vs} N{\'a}dvorn{\'i}k and Eva Schmoranzerova and Petr Němec},
  journal={New Journal of Physics},
  year={2020}
}

• M. Surýnek, L. Nádvorník, +1 author P. Němec
• Published 7 April 2020
• Physics
• New Journal of Physics

We report on a quasi-nondegenerate pump-probe technique that is based on spectral-filtration of femtosecond laser pulses by a pair of mutually-spectrally-disjunctive interference filters. This cost- and space-efficient approach can be used even in pump-probe microscopy where collinear propagation of pump and probe pulses is dictated by utilization of a microscopic objective. This technique solves the contradictory requirements on an efficient removal of pump photons from the probe beam, to achieve a good signal-to-noise ratio, simultaneously with a needed spectral proximity of the excitation and probing, which is essential for magnetooptical study of many material systems. Importantly, this spectral-filtration of 100 fs long laser pulses does not affect considerably the resulting time-resolution, which remains well below 500 fs. We demonstrate the practical applicability of this technique with close but distinct wavelengths of pump and probe pulses in spatially- and time-resolved spin-sensitive magnetooptical Kerr effect (MOKE) experiment in GaAs/AlGaAs heterostructure, where a high-mobility spin system is formed after optical injection of electrons at wavelengths close to MOKE resonance. In particular, we studied the time- and spatial-evolutions of charge-related (reflectivity) and spin-related (MOKE) signals. We revealed that they evolve in a similar but not exactly the same way which we attributed to interplay of several electron many-body effects in GaAs.