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arXiv · 2202.09239

Self-Kerr effect across the yellow $\mathrm{Cu_2O}$ Rydberg series

Corentin Morin·Jérôme Tignon·Juliette Mangeney·Sukhdeep Dhillon·Gerard Czajkowski·Karol Karpiński·Sylwia Zielińska-Raczyńska·David Ziemkiewicz·Thomas Boulier
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Abstract

We investigate the nonlinear refraction induced by Rydberg excitons in $\mathrm{Cu_2O}$. Using a high-precision interferometry imaging technique that spatially resolves the nonlinear phase shift, we observe significant shifts at extremely low laser intensity near each exciton resonance. From this, we derive the nonlinear index $\mathrm{n_2}$, present the $\mathrm{n_2}$ spectrum for $n\geq 5$ and report large $\mathrm{n_2}$ values of order $10^{-3}$ mm$^2$/mW. Moreover, we observe a rapid saturation of the Kerr nonlinearity and find that the saturation intensity $\mathrm{I_{sat}}$ decreases as $n^{-7}$. We explain this with the Rydberg blockade mechanism, whereby giant Rydberg interactions limit the exciton density, resulting in a maximum phase shift of 0.5 rad in our setup.

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Corentin Morin, Jérôme Tignon, Juliette Mangeney, Sukhdeep Dhillon, Gerard Czajkowski, Karol Karpiński, Sylwia Zielińska-Raczyńska, David Ziemkiewicz, Thomas Boulier. 2022-02-18. Self-Kerr effect across the yellow $\mathrm{Cu_2O}$ Rydberg series. https://arxiv.org/abs/2202.09239

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