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arXiv · 2102.06119

Electroabsorption in gated GaAs nanophotonic waveguides

Ying Wang·Ravitej Uppu·Xiaoyan Zhou·Camille Papon·Sven Scholz·Andreas D. Wieck·Arne Ludwig·Peter Lodahl·Leonardo Midolo
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Abstract

We report on the analysis of electroabsorption in thin GaAs/Al$_{0.3}$Ga$_{0.7}$As nanophotonic waveguides with an embedded $p$-$i$-$n$ junction. By measuring the transmission through waveguides of different lengths, we derive the propagation loss as a function of electric field, wavelength, and temperature. The results are in good agreement with the Franz-Keldysh model of electroabsorption extending over 200 meV below the GaAs bandgap, i.e. in the 910--970 nm wavelength range. We find a pronounced residual absorption in forward bias, which we attribute to Fermi-level pinning at the waveguide surface, producing over 20 dB/mm loss at room temperature. These results are essential for understanding the origin of loss in nanophotonic devices operating in the emission range of self-assembled InAs semiconductor quantum dots, towards the realization of scalable quantum photonic integrated circuits.

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Ying Wang, Ravitej Uppu, Xiaoyan Zhou, Camille Papon, Sven Scholz, Andreas D. Wieck, Arne Ludwig, Peter Lodahl, Leonardo Midolo. 2021-02-11. Electroabsorption in gated GaAs nanophotonic waveguides. https://doi.org/10.1063/5.0039373

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