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arXiv · 2204.04870

Second-harmonic generation in germanium-on-insulator from visible to telecom wavelengths

Yadong Wang·Daniel Burt·Kunze Lu·Donguk Nam
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Abstract

The second-order $\chi^{2}$ process underpins many important nonlinear optical applications in the field of classical and quantum optics. Generally, the $\chi^{2}$ process manifests itself only in a non-centrosymmetric dielectric medium via an anharmonic electron oscillation when driven by an intense optical field. Due to inversion symmetry, group-IV semiconductors like silicon (Si) and germanium (Ge) are traditionally not considered as ideal candidates for second-order nonlinear optics applications. Here, we report the experimental observation of the second-harmonic generation (SHG) in a Ge-on-insulator (GOI) sample under femtosecond optical pumping. Specially, we report the first-time measurement of the SHG signal from a GOI sample in the telecom S-band by pumping at $\sim$$3000$ nm.

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Yadong Wang, Daniel Burt, Kunze Lu, Donguk Nam. 2022-04-11. Second-harmonic generation in germanium-on-insulator from visible to telecom wavelengths. https://doi.org/10.1063/5.0095666

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