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arXiv · 2507.11425

Exciton-resonant detection of high-frequency surface acoustic waves from subwavelength metal gratings

Olga Ken·Dmytro Horiachyi·Ilya Akimov·Vladimir Korenev·Vitalyi Gusev·Leonid Litvin·Michael Kahl·Arne Ludwig·Nikolai Spitzer·Andreas D. Wieck·Manfred Bayer
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Abstract

We report on all-optical generation and detection of high-frequency (up to about 30 GHz) surface acoustic waves (SAWs) in GaAs/AlGaAs heterostructures with short-period Au gratings on top. A highly sensitive method for SAW detection is demonstrated using a polarization-resolved pump-probe technique that exploits the narrow exciton resonance in high-quality GaAs. The elastic strain of the SAW modulates the exciton energy in the time domain. As a result, even a small deformation produces a noticeable change in the dielectric function at the detection wavelength leading to an order of magnitude increase in the detection sensitivity as compared to off-resonant conditions. A theoretical model is developed that considers two detection schemes: one accounting for probe light diffraction and one corresponding to a non-diffractive situation.

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Olga Ken, Dmytro Horiachyi, Ilya Akimov, Vladimir Korenev, Vitalyi Gusev, Leonid Litvin, Michael Kahl, Arne Ludwig, Nikolai Spitzer, Andreas D. Wieck, Manfred Bayer. 2025-07-15. Exciton-resonant detection of high-frequency surface acoustic waves from subwavelength metal gratings. https://doi.org/10.1103/72ym-hc78

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