article published yes Vladimir Spedt author Falco Meier author René Geromel author Pascal Mahler author Tobias Henksmeier author 42539 Dirk Reuter author 37763 Thomas Zentgraf author 305250000-0002-8662-1101 Cedrik Meier author 20798https://orcid.org/0000-0002-3787-3572 15 department TRR 142 - Project Area B project TRR 142; TP B09: Effiziente Erzeugung mit maßgeschneiderter optischer Phaselage der zweiten Harmonischen mittels Quasi-gebundener Zustände in GaAs Metaoberflächen project <jats:p>Efficient detection of near-infrared light at telecommunication wavelengths remains a central challenge for GaAs-based photonic and optoelectronic devices due to the absence of linear absorption below the bandgap. Here, we demonstrate a hybrid nonlinear optoelectronic device that enhances the detection efficiency of a (001)-oriented GaAs PIN photodiode under telecommunication-wavelength illumination, where absorption is intrinsically limited to two-photon absorption (2PA). Our approach relies on the integration of a transferred, nanopatterned 385 nm-thick (111)-oriented GaAs nanofilm acting as an on-chip nonlinear frequency-conversion layer. Elliptical GaAs nanoresonators are employed to enhance second-harmonic generation (SHG) resonantly, converting incident 1550 nm radiation into above-bandgap photons efficiently absorbed by the underlying diode. Spatially resolved current–voltage measurements reveal a pronounced enhancement of the detector response in regions covered by the nanoantennas. The device exhibits a low dark current, while the metasurface-covered regions show the largest current response under 1560 nm excitation compared to the bare GaAs(100) diode and the unstructured GaAs(111) film. These results establish a direct functional link between dielectric metasurface–based nonlinear frequency conversion and electrical photodetection, providing a viable route toward integrated sub-bandgap detection schemes.</jats:p> https://ris.uni-paderborn.de/download/66674/66675/oe-34-16-30335.pdf application/pdf Optica Publishing Group2026 eng 1094-408710.1364/oe.601288 3416 V. Spedt <i>et al.</i>, “Hybrid GaAs (111)/GaAs (100) PIN photodiodes for metasurface-assisted nonlinear upconversion detection,” <i>Optics Express</i>, vol. 34, no. 16, Art. no. 30335, 2026, doi: <a href="https://doi.org/10.1364/oe.601288">10.1364/oe.601288</a>. Spedt, V., Meier, F., Geromel, R., Mahler, P., Henksmeier, T., Reuter, D., Zentgraf, T., &#38; Meier, C. (2026). Hybrid GaAs (111)/GaAs (100) PIN photodiodes for metasurface-assisted nonlinear upconversion detection. <i>Optics Express</i>, <i>34</i>(16), Article 30335. <a href="https://doi.org/10.1364/oe.601288">https://doi.org/10.1364/oe.601288</a> V. Spedt, F. Meier, R. Geromel, P. Mahler, T. Henksmeier, D. Reuter, T. Zentgraf, C. Meier, Optics Express 34 (2026). Spedt, Vladimir, Falco Meier, René Geromel, Pascal Mahler, Tobias Henksmeier, Dirk Reuter, Thomas Zentgraf, and Cedrik Meier. “Hybrid GaAs (111)/GaAs (100) PIN Photodiodes for Metasurface-Assisted Nonlinear Upconversion Detection.” <i>Optics Express</i> 34, no. 16 (2026). <a href="https://doi.org/10.1364/oe.601288">https://doi.org/10.1364/oe.601288</a>. Spedt, Vladimir, et al. “Hybrid GaAs (111)/GaAs (100) PIN Photodiodes for Metasurface-Assisted Nonlinear Upconversion Detection.” <i>Optics Express</i>, vol. 34, no. 16, 30335, Optica Publishing Group, 2026, doi:<a href="https://doi.org/10.1364/oe.601288">10.1364/oe.601288</a>. @article{Spedt_Meier_Geromel_Mahler_Henksmeier_Reuter_Zentgraf_Meier_2026, title={Hybrid GaAs (111)/GaAs (100) PIN photodiodes for metasurface-assisted nonlinear upconversion detection}, volume={34}, DOI={<a href="https://doi.org/10.1364/oe.601288">10.1364/oe.601288</a>}, number={1630335}, journal={Optics Express}, publisher={Optica Publishing Group}, author={Spedt, Vladimir and Meier, Falco and Geromel, René and Mahler, Pascal and Henksmeier, Tobias and Reuter, Dirk and Zentgraf, Thomas and Meier, Cedrik}, year={2026} } Spedt V, Meier F, Geromel R, et al. Hybrid GaAs (111)/GaAs (100) PIN photodiodes for metasurface-assisted nonlinear upconversion detection. <i>Optics Express</i>. 2026;34(16). doi:<a href="https://doi.org/10.1364/oe.601288">10.1364/oe.601288</a> 666742026-08-06T12:15:59Z2026-08-06T12:18:58Z