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arXiv · 2407.09243

${\chi}^{(2)}$-Induced Artifact Overwhelming the Third-Order Signal in 2D Raman-THz Spectroscopy of Non-Centrosymmetric Materials

Seyyed Jabbar Mousavi·Megan F. Biggs·Jeremy A. Johnson·Peter Hamm·Andrey Shalit
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Abstract

Through comprehensive data analysis, we demonstrate that a ${\chi}^{(2)}$-induced artifact, arising from imperfect balancing in the conventional electro-optic sampling (EOS) detection scheme, contributes significantly to the measured signal in 2D Raman-THz spectroscopy of non-centrosymmetric materials. The artifact is a product of two 1D responses, overwhelming the desired 2D response. We confirm that by analyzing the 2D Raman-THz response of a x-cut beta barium borate (BBO) crystal. We furthermore show that this artifact can be effectively suppressed by implementing a special detection scheme. We successfully isolate the desired third-order 2D Raman-THz response, revealing a distinct cross-peak feature, whose frequency position suggests the coupling between two crystal phonons.

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Seyyed Jabbar Mousavi, Megan F. Biggs, Jeremy A. Johnson, Peter Hamm, Andrey Shalit. 2024-07-12. ${\chi}^{(2)}$-Induced Artifact Overwhelming the Third-Order Signal in 2D Raman-THz Spectroscopy of Non-Centrosymmetric Materials. https://arxiv.org/abs/2407.09243

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