Polarization- and time-resolved nonlinear multi-photon spectroscopy for confocal microscopy of semiconductor nanostructures

Nikita V. Siverin; Andreas Farenbruch; Dmitri R. Yakovlev; Daniel J. Gillard; Xuerong Hu; Alexander I. Tartakovskii; Manfred Bayer

arXiv · 2508.18026

Polarization- and time-resolved nonlinear multi-photon spectroscopy for confocal microscopy of semiconductor nanostructures

Nikita V. Siverin·Andreas Farenbruch·Dmitri R. Yakovlev·Daniel J. Gillard·Xuerong Hu·Alexander I. Tartakovskii·Manfred Bayer

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Abstract

We present a versatile confocal microscopy setup for optical second harmonic generation (SHG) and multi-photon spectroscopy that enables polarization-resolved studies of semiconductor bulk crystals and low-dimensional structures. The system offers full polarization control in both excitation and detection, spatial scanning with micrometer resolution, and spectrally tunable excitation over a broad energy range from 0.5 to 4.0 eV, using femtosecond and picosecond laser pulses. Samples are mounted in a helium-flow cryostat, allowing temperature control from 4 to 300 K. Magnetic fields up to 0.625 T can be applied in the Voigt geometry via an electromagnet. The nonlinear optical signals are analyzed using a high-resolution spectrometer with a spectral resolution of 60 $\mu$eV. We demonstrate the potential of the setup by means of SHG polarization tomography measurements on a Cu$_2$O crystal as well as through a SHG spectral scan of a ZnSe crystal over a wide energy range from 1.4 to 3.1 eV. Polarization-resolved confocal SHG mapping of various twisted mono- and bilayer MoS$_2$ structures is also presented. In addition, time-resolved two-color pump-probe experiments are shown for a Cs$_2$AgBiBr$_6$ crystal, illustrating the potential of the system for investigating coherent exciton and phonon dynamics.

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Nikita V. Siverin, Andreas Farenbruch, Dmitri R. Yakovlev, Daniel J. Gillard, Xuerong Hu, Alexander I. Tartakovskii, Manfred Bayer. 2025-08-25. Polarization- and time-resolved nonlinear multi-photon spectroscopy for confocal microscopy of semiconductor nanostructures. https://arxiv.org/abs/2508.18026

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