Hetero-integrated diamond-on-AlGaN/AlN waveguides for optical color center interfacing
S. Gündoğdu1,2, L.M. Rektorschek1, M.E. Stucki1,2, M.H. van der Hoeven1, T. Kolbe2, S. Hagedorn2, M. Weyers2, T. Pregnolato1,2, J.M. Bopp1,2 & T. Schröder1,2
Published in:
npj Nanophoton., vol. 3, art. 9, doi:10.1038/s44310-025-00099-w (2026).
Abstract:
Quantum photonic devices require efficient access to solid-state spin qubits serving as quantum memories or single-photon sources and nonlinearities. Additionally, they demand nonlinear and electro-optic components for frequency converters and phase shifters. The serial production of quantum devices needs the on-chip integration of all these photonic components. These requirements motivate the hetero-integration of materials with complementary properties. Diamond color centers provide access to spin registers, long coherence times, and suitability for quantum networking. In contrast, aluminum gallium nitride-on-aluminum nitride (AlGaN/AlN) photonics features second-order nonlinear and first-order electro-optic effects. Here, we demonstrate the accurate integration of diamond waveguides containing nitrogen-vacancy (NV) centers into AlGaN/AlN waveguides using a pick-and-place method. Both waveguides possess tapered sections for adiabatic mode transfer. We model the tapered diamond-AlGaN/AlN interface with finite element simulations, implementing fabrication constraints and placement uncertainties. Measured coupling efficiencies coincide closely with simulation model predictions.
1 Humboldt-Universität zu Berlin, Department of Physics, Berlin, Germany
2 Ferdinand-Braun-Institut (FBH), Berlin, Germany
© The Author(s) 2026
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Rightslink® by Copyright Clearance Center
Full version in pdf-format.