@article{63827, abstract = {{Light-emitting diodes (LEDs) are becoming increasingly important across various sectors of the lighting industry and are being used more frequently. In the field of symbolic projection, research is increasingly focusing on implementing light modulation using energy-efficient, incoherent LEDs rather than lasers. Since light modulation in micro- and nano-optics is typically achieved through phase modulation, Finite-Difference Time-Domain (FDTD) simulations are employed for analysis. The objective of this article is to investigate different approaches for approximating incoherent monochromatic light sources within FDTD simulations. To this end, two approaches based on dipole sources are considered, as well as a method involving plane waves with modulated wavefronts based on Cosine–Fourier functions and a method based on the superposition of Gaussian beams. These methods are evaluated in terms of their accuracy using a two-dimensional double-slit configuration and are compared against a fully incoherent analytical reference.}}, author = {{Metzner, Dominik and Potthoff, Jens and Zentgraf, Thomas and Förstner, Jens}}, issn = {{2304-6732}}, journal = {{Photonics}}, keywords = {{tet_topic_opticalantenna, tet_topic_numerics, tet_topic_meta}}, number = {{2}}, publisher = {{MDPI AG}}, title = {{{Approximating Incoherent Monochromatic Light Sources in FDTD Simulations}}}, doi = {{10.3390/photonics13020128}}, volume = {{13}}, year = {{2026}}, } @article{64873, abstract = {{Continuous flow catalysis utilizing gel-bound organocatalysts within a microfluidic reactor represents a compelling strategy in the realm of organic synthesis. In this study, a quinuclidine-based catalytic monomer (QMA) was synthesized to create polymer gel dots through the process of photopolymerization that serve as a support for the catalyst. The resulting gel-bound organocatalysts were assembled within a continuous microfluidic reactor to facilitate the Baylis–Hillman reaction between various aldehydes and acrylonitrile at a temperature of 50 °C. The conversion of the product was assessed using 1H NMR spectroscopy as an offline analytical method over a duration of 8 h. The findings indicated that highly reactive aldehydes achieved conversion rates exceeding 90%, in contrast to their less reactive counterparts. Furthermore, these results were juxtaposed with previously published data derived from alternative synthetic methodologies, revealing that the continuous microfluidic reactions employing integrated organocatalysts within polymer networks exhibited significantly higher conversions with reduced reaction times (8 h) at the same temperature (50 °C). Additionally, the influence of different geometries (round, triangular, and square) of the gel dots on catalytic activity was investigated, with round and square gel dots demonstrating slightly superior performance compared with triangular gel dots, attributed to their increased surface area. Moreover, an extended reaction period of 6 days was conducted using 4-bromobenzaldehyde and acrylonitrile, resulting in a conversion rate exceeding 70%, which remained stable for 5 days before experiencing a slight decline due to product accumulation on the gel dots.}}, author = {{Killi, Naresh and Kumar, Amit and Nebhani, Leena and Obst, Franziska and Richter, Andreas and Reineke Matsudo, Bernhard and Zentgraf, Thomas and Kuckling, Dirk}}, issn = {{2470-1343}}, journal = {{ACS Omega}}, number = {{9}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Integrating an Organocatalyst into a Polymeric Gel Framework for the Continuous Microflow Baylis–Hillman Reaction}}}, doi = {{10.1021/acsomega.5c09476}}, volume = {{11}}, year = {{2026}}, } @article{61523, abstract = {{AbstractMetasurface holography offers a powerful approach for manipulating wavefronts at the nano and micro scale. Extensive research has been conducted to enhance the multiplexing capacity for diverse wavefronts. However, the independence of multiplexed channels is fundamentally restricted in techniques using single‐layer metasurfaces, resulting in unavoidable crosstalk and the need for post‐filtering of the output wavefronts. Here, a universal wavefront multiplexing concept is presented based on non‐injective transformation. By employing joint optimization on two metasurfaces, different channels can be independently designed without any constraints on the output wavefronts. To validate this approach, ultra‐compact orbital angular momentum (OAM) sorters are designed. In these experiments, the output beams from different channels can be independently mapped to 2D positions with high fineness. In another application of wavefront‐multiplexed holography, 10‐channel multiplexing is experimentally achieved with minimal crosstalk and without the need for post‐processing. These results demonstrate the independence between channels enabled by the non‐injective transformation in the method. The precise wavefront control and high multiplexing capacity underscore its potential for scalable wavefront manipulation devices.}}, author = {{Jin, Xiao and Zentgraf, Thomas}}, issn = {{0935-9648}}, journal = {{Advanced Materials}}, publisher = {{Wiley}}, title = {{{Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation}}}, doi = {{10.1002/adma.202511823}}, volume = {{38}}, year = {{2026}}, } @article{64978, abstract = {{The degrees of freedom (DoFs) of light determine the maximum number of independent signal channels an optical system can support. However, the polarization DoF is intrinsically limited to two by orthogonality, which causes unavoidable crosstalk and often forces position multiplexing, where different channels are assigned to distinct spatial locations to suppress crosstalk. This research introduces a multilayer synchronous polarization projection method that fundamentally increases the DoF for polarization multiplexing. The DoF equals twice the number of projection layers. We experimentally demonstrate six- channel polarization multiplexing holography without position multiplexing. The six-channel multiplexing results indicate that our approach exceeds the conventional polarization multiplexing method, yielding an average 3.79 dB improvement in extinction ratio across the six channels. Compared with the theoretical limit of traditional polarization multiplexing, our method reduces crosstalk by an average of 6.52 dB across all channels in a seven-channel design. The polarization projection method breaks the DoF limitation of polarization multiplexing, opening a path toward high-dimensional photonic information encoding for communication, encryption, and imaging.}}, author = {{Jin, Xiao and Zentgraf, Thomas}}, issn = {{2577-5421}}, journal = {{Advanced Photonics}}, number = {{02}}, publisher = {{SPIE-Intl Soc Optical Eng}}, title = {{{Increasing the design degree of freedom for polarization through multilayer synchronous polarization projection}}}, doi = {{10.1117/1.ap.8.2.026010}}, volume = {{8}}, year = {{2026}}, } @inproceedings{65357, author = {{Kim, Minjun and Devaraj, Vasanthan and Seo, Hyeon-Seok and Eom, Seongjae and Lee, Jeong-Su and Lee, Donghan and Zentgraf, Thomas and Lee, Jong-Min and Jeon, Min Yong}}, booktitle = {{Quantum Sensing and Nano Electronics and Photonics XXII}}, editor = {{Razeghi, Manijeh and Khodaparast, Giti A. and Vitiello, Miriam S.}}, publisher = {{SPIE}}, title = {{{Fabrication of uniform, high-field-enhanced plasmonic satellite clusters using multidewetting}}}, doi = {{10.1117/12.3095416}}, year = {{2026}}, } @article{65460, abstract = {{Beamsplitters represent fundamental components in both classical and quantum optical systems, enabling the distribution of light, as well as the generation of interference, superposition, and entanglement. However, optical networks constructed from conventional bulk 2 × 2-beamsplitters encounter inherent scalability issues, as the number of required beamsplitters scales quadratically with the number of optical modes for a fully connected network. Metasurfaces offer a promising route to overcome these constraints. By manipulating light at the wavelength scale, compact optical components with advanced functionalities can be constructed, which address several modes simultaneously. In this work, we design and experimentally utilize a metasurface as a multiport beamsplitter. Furthermore, we realized a multimode interferometer composed of two cascaded metasurfaces. We characterize the individual and cascaded metasurfaces by using classical light, showing controllable splitting ratios through tunable phase relations. We then expand the approach to quantum light, employing single photons to demonstrate second- and third-order photon correlations as well as single photon interference across multiple spatial paths. These results establish metasurface-based multiport beamsplitters as a scalable and reconfigurable platform bridging classical and quantum photonics. }}, author = {{Aschwanden, Rebecca and Claro-Rodríguez, Nicolás and Zhao, Ruizhe and Kallert, Patricia Anna Maria and Krieger, Tobias and Buchinger, Quirin and Covre da Silva, Saimon F. and Stroj, Sandra and Rota, Michele and Höfling, Sven and Huber-Loyola, Tobias and Rastelli, Armando and Trotta, Rinaldo and Huang, Lingling and Bartley, Tim and Jöns, Klaus and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{metasurface, beamsplitter, interferometer, quantum network, single photons, nanophotonics}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Cascaded Metasurface Interferometer for Multipath Interference with Classical and Quantum Light}}}, doi = {{10.1021/acsphotonics.6c00096}}, year = {{2026}}, } @article{65316, abstract = {{Metasurfaces are powerful tools for manipulating light using small structures on the nanoscale. In most metasurfaces, near-field couplings are treated as being unfavorable perturbations. Here, we experimentally investigate a structure consisting of sinusoidally modulated silicon waveguides where near-field coupling of local resonances leads to negative coupling, i.e., a negative coupling constant. This gives rise to wave-vector-dependent eigenstates of elliptical, linear, and circular polarizations. In particular, fully circular polarization states are not only present at a single point in momentum space (k-space) but also along a line. This circular polarization line, as well as a linear polarization line, emanates from a polarization degeneracy at the Dirac point. We experimentally validate the existence of these eigenstates and demonstrate the energy-, polarization-, and wave vector dependence of this metasurface as well as its sensitivity to fabrication tolerances. By tuning the incident k-vector, certain polarization-energy eigenstates are strongly reflected, allowing for uses in angle-tunable polarization filters and light sources.}}, author = {{Wetter, Helene and Wingenbach, Jan and Rehberg, Falk and Gao, Wenlong and Schumacher, Stefan and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{metasurface, waveguides, Dirac point, polarization, negative coupling}}, pages = {{2128--2133}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling}}}, doi = {{10.1021/acsphotonics.5c02865}}, volume = {{13}}, year = {{2026}}, } @article{65655, abstract = {{A functionalization-free plasmonic nanogap platform enables reliable on-site SERS based oxidation-state differentiation of arsenic through uniform metal-vacuum-metal cavities with high electromagnetic enhancement and minimal background interference.}}, author = {{Kim, Minjun and Heo, Damun and Cho, Sung Yoon and Lee, Ye-Won and Gu, Sun-Hwa and Adhikari, Samir and Lee, Donghan and Jeong, Seok Soon and Kim, Hyuck Soo and Devaraj, Vasanthan and Zentgraf, Thomas and Jeon, Min Yong and Lee, Jong-Min}}, issn = {{2040-3364}}, journal = {{Nanoscale}}, number = {{8}}, pages = {{4292--4299}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{A functionalization-free plasmonic hole-sphere nanogap SERS platform for reliable on-site analysis and oxide-state classification}}}, doi = {{10.1039/d5nr03414k}}, volume = {{18}}, year = {{2026}}, } @inproceedings{65906, author = {{Jin, Xiao and Zentgraf, Thomas}}, booktitle = {{Metamaterials XV}}, editor = {{MacDonald, Kevin F. and Zayats, Anatoly V. and Staude, Isabelle}}, location = {{Strasbourg, France}}, publisher = {{SPIE}}, title = {{{OAM-multiplexed holography via cascaded metasurfaces without post sampling and position multiplexing}}}, doi = {{10.1117/12.3096579}}, volume = {{14075}}, year = {{2026}}, } @article{66555, abstract = {{Scalable plasmonic technologies face a critical trade‐off: few‐body architectures offer high enhancement but are sensitive to fabrication flaws, while scalable methods like solid‐state dewetting yield large, low‐enhancement gaps. We introduce a paradigm shift using a many‐body plasmonic architecture inspired by statistical mechanics. By moving toward the continuum limit, local geometric variations are statistically averaged out, effectively decoupling optical performance from microscopic disorder. We implement this concept via a lithography‐ and etching‐free, multi‐step dewetting strategy, creating wafer‐scale nanoclusters. This process strategically forms a robust many‐body system by introducing numerous small satellite nanoparticles between larger particles. Crucially, this design achieves a high collective enhancement that surpasses even optimized few‐body systems, despite having larger individual gaps. Under optimized conditions, these substrates exhibit a surface‐enhanced Raman scattering enhancement factor approaching 4 × 10^8 with unprecedented reproducibility (RSD of ∼10%). This scalable, low‐cost concept establishes a practical route toward reproducible wafer‐scale nanophotonic platforms for sensing, spectroscopy, and quantum technologies.}}, author = {{Kim, Minjun and Devaraj, Vasanthan and Seo, Hyeon‐Seok and Eom, Seong‐Jae and Lee, Jeong‐Su and Lee, Donghan and Jeon, Min Yong and Zentgraf, Thomas and Lee, Jong‐Min}}, issn = {{1863-8880}}, journal = {{Laser & Photonics Reviews}}, publisher = {{Wiley}}, title = {{{Engineering Disordered Many‐Particle Plasmonic Nanoclusters for Wafer‐Scale Uniform and Giant Electromagnetic Field Enhancement}}}, doi = {{10.1002/lpor.71610}}, year = {{2026}}, } @article{66674, abstract = {{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.}}, author = {{Spedt, Vladimir and Meier, Falco and Geromel, René and Mahler, Pascal and Henksmeier, Tobias and Reuter, Dirk and Zentgraf, Thomas and Meier, Cedrik}}, issn = {{1094-4087}}, journal = {{Optics Express}}, number = {{16}}, publisher = {{Optica Publishing Group}}, title = {{{Hybrid GaAs (111)/GaAs (100) PIN photodiodes for metasurface-assisted nonlinear upconversion detection}}}, doi = {{10.1364/oe.601288}}, volume = {{34}}, year = {{2026}}, } @article{66632, abstract = {{Three‐dimensional (3D) assemblies of gold nanoparticles (AuNPs) offer a rich platform for plasmonic coupling and near‐field engineering, yet their optical behavior is often complex due to structural disorder and fabrication‐induced variability. Here, we present a systematic optical investigation of large‐scale 3D AuNP assemblies fabricated via meniscus‐guided assembly, focusing on the reproducibility, spatial uniformity, and mode evolution of their plasmonic responses. Spatially‐resolved dark‐field scattering measurements reveal that high‐aspect‐ratio AuNP pillars exhibit uniform scattering spectra along their height and across different pillars, despite variations in geometry and structure. Electromagnetic simulations suggest that this robustness arises from a collective many‐particle plasmonic response that remains optically active despite structural perturbations. The corresponding near‐field and surface‐charge distributions remain spatially distributed under representative structural perturbations, consistent with volumetric averaging across the three‐dimensional assembly. Building on this robust platform, we introduce compositional modulation through a core–satellite architecture by incorporating smaller AuNPs. This yields a composition‐dependent spectral redistribution, including the emergence of an additional long‐wavelength spectral feature in the core–satellite assemblies. Wavelength‐dependent surface‐enhanced Raman scattering measurements reveal contrasting responses under 633 and 785 nm excitation, reflecting redistribution of local plasmonic coupling pathways. These results provide process‐enabled guidelines for using meniscus‐guided 3D‐nanoprinting to realize robust nanoparticle assemblies.}}, author = {{Devaraj, Vasanthan and Kwak, Sunghyun and Kim, Hyeongjip and Sung, Sang‐Keun and Lee, Jong‐Min and Zentgraf, Thomas and Kim, Won‐Geun}}, issn = {{1863-8880}}, journal = {{Laser & Photonics Reviews}}, publisher = {{Wiley}}, title = {{{Spatially Uniform and Defect‐Tolerant Plasmonic Responses in 3D Printed Gold Nanoparticle Assemblies}}}, doi = {{10.1002/lpor.71686}}, year = {{2026}}, } @inproceedings{60022, author = {{Brauckmann, Michael and Narvaez Castaneda, Emmanuel and Siebert, Dustin and Brecht, Benjamin and Förstner, Jens and Zentgraf, Thomas}}, booktitle = {{Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics}}, location = {{Malaga, Spain}}, title = {{{Enhancement Of Light-matter Interaction In Topological Waveguides And Resonators}}}, year = {{2025}}, } @article{62286, abstract = {{Optical tweezer arrays of laser-cooled and individually controlled particles have revolutionized atomic, molecular, and optical physics. They afford exquisite capabilities for applications in quantum simulation of many-body physics, quantum computation, and sensing. Underlying this development is the technical maturity of generating scalable optical beams, enabled by active components and a high numerical aperture objective. However, such a complex combination of bulk optics outside the vacuum chamber is very sensitive to any vibration and drift. Here, we demonstrate the generation of a 3 × 3 static tweezer array with a single chip-scale multifunctional metasurface element in vacuum, replacing the meter-long free space optics. Fluorescence counts on the camera validate the successful trapping of the atomic ensemble array and showcase a promising strategy for integrated photonics with cold atom systems. The introduction of a polarization independent dual-wavelength metasurface significantly enhances fluorescence collection efficiency while reducing experimental complexity. This approach paves the way for scalable neutral atom platforms and offers a compelling route towards the realization of next generation quantum metasurfaces.}}, author = {{Li, Donghao and Liao, Qiming and Xu, Beining and Zentgraf, Thomas and Narvaez Castaneda, Emmanuel and Zhou, Yaoting and Qin, Keyu and Xu, Zhongxiao and Shen, Heng and Huang, Lingling}}, issn = {{1094-4087}}, journal = {{Optics Express}}, number = {{24}}, publisher = {{Optica Publishing Group}}, title = {{{In vacuum metasurface for optical microtrap array}}}, doi = {{10.1364/oe.580201}}, volume = {{33}}, year = {{2025}}, } @inproceedings{61352, author = {{Devaraj, Vasanthan and Ruiz Alvarado, Isaac Azahel and Lee, Jongmin and Oh, Jin-Woo and Gerstmann, Uwe and Schmidt, Wolf Gero and Zentgraf, Thomas}}, booktitle = {{2025 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)}}, publisher = {{IEEE}}, title = {{{Dynamic and Reversible Plasmonic Nanogaps From Isolated Dimer Nanoparticles via Self-Assembly}}}, doi = {{10.1109/cleo/europe-eqec65582.2025.11109762}}, year = {{2025}}, } @article{58642, abstract = {{We present a cost-effective self-assembly method to fabricate low-density dimer NPs in an NPoM architecture, using the M13 phage as a spacer layer. This will enable the development of dynamic plasmonic devices and advanced sensing applications.}}, author = {{Devaraj, Vasanthan and Ruiz Alvarado, Isaac Azahel and Lee, Jong-Min and Oh, Jin-Woo and Gerstmann, Uwe and Schmidt, Wolf Gero and Zentgraf, Thomas}}, issn = {{2055-6756}}, journal = {{Nanoscale Horizons}}, pages = {{537--548}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror}}}, doi = {{10.1039/d4nh00546e}}, volume = {{10}}, year = {{2025}}, } @article{58606, author = {{Mathew, Albert and Aschwanden, Rebecca and Tripathi, Aditya and Jangid, Piyush and Sain, Basudeb and Zentgraf, Thomas and Kruk, Sergey}}, issn = {{1530-6984}}, journal = {{Nano Letters}}, keywords = {{metasurfaces, nanophotonics, nonreciprocity, optical isolators, silicon photonics}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials}}}, doi = {{10.1021/acs.nanolett.4c06188}}, year = {{2025}}, } @article{51519, author = {{Cui, Tie Jun and Zhang, Shuang and Alu, Andrea and Wegener, Martin and Pendry, John and Luo, Jie and Lai, Yun and Wang, Zuojia and Lin, Xiao and Chen, Hongsheng and Chen, Ping and Wu, Rui-Xin and Yin, Yuhang and Zhao, Pengfei and Chen, Huanyang and Li, Yue and Zhou, Ziheng and Engheta, Nader and Asadchy, V. S. and Simovski, Constantin and Tretyakov, Sergei A and Yang, Biao and Campbell, Sawyer D. and Hao, Yang and Werner, Douglas H and Sun, Shulin and Zhou, Lei and Xu, Su and Sun, Hong-Bo and Zhou, Zhou and Li, Zile and Zheng, Guoxing and Chen, Xianzhong and Li, Tao and Zhu, Shi-Ning and Zhou, Junxiao and Zhao, Junxiang and Liu, Zhaowei and Zhang, Yuchao and Zhang, Qiming and Gu, Min and Xiao, Shumin and Liu, Yongmin and Zhang, Xiaoyu and Tang, Yutao and Li, Guixin and Zentgraf, Thomas and Koshelev, Kirill and Kivshar, Yuri S. and Li, Xin and Badloe, Trevon and Huang, Lingling and Rho, Junsuk and Wang, Shuming and Tsai, Din Ping and Bykov, A. Yu. and Krasavin, Alexey V and Zayats, Anatoly V and McDonnell, Cormac and Ellenbogen, Tal and Luo, Xiangang and Pu, Mingbo and Garcia-Vidal, Francisco J and Liu, Liangliang and Li, Zhuo and Tang, Wenxuan and Ma, Hui Feng and Zhang, Jingjing and Luo, Yu and Zhang, Xuanru and Zhang, Hao Chi and He, Pei Hang and Zhang, Le Peng and Wan, Xiang and Wu, Haotian and Liu, Shuo and Jiang, Wei Xiang and Zhang, Xin Ge and Qiu, Chengwei and Ma, Qian and Liu, Che and Li, Long and Han, Jiaqi and Li, Lianlin and Cotrufo, Michele and Caloz, Christophe and Deck-Léger, Z.-L. and Bahrami, A. and Céspedes, O. and Galiffi, Emanuele and Huidobro, P. A. and Cheng, Qiang and Dai, Jun Yan and Ke, Jun Cheng and Zhang, Lei and Galdi, Vincenzo and Di Renzo, Marco}}, issn = {{2515-7647}}, journal = {{Journal of Physics: Photonics}}, keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}}, publisher = {{IOP Publishing}}, title = {{{Roadmap on electromagnetic metamaterials and metasurfaces}}}, doi = {{10.1088/2515-7647/ad1a3b}}, year = {{2024}}, } @inproceedings{60023, author = {{Wetter, Helene and Gao, Wenlong and Rehberg, Falk and Wingenbach, Jan and Schumacher, Stefan and Zentgraf, Thomas}}, booktitle = {{Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics}}, issn = {{2429-1390}}, location = {{Toyama, Japan}}, title = {{{Dielectric metasurface for wave-vector variant and circular polarization dependent transmission}}}, year = {{2024}}, } @article{61255, abstract = {{Abstract Topological states have been widely investigated in different types of systems and lattices. In the present work, we report on topological edge states in double-wave (DW) chains, which can be described by a generalized Aubry-André-Harper (AAH) model. For the specific system of a driven-dissipative exciton polariton system we show that in such potential chains, different types of edge states can form. For resonant optical excitation, we further find that the optical nonlinearity leads to a multistability of different edge states. This includes topologically protected edge states evolved directly from individual linear eigenstates as well as additional edge states that originate from nonlinearity-induced localization of bulk states. Extending the system into two dimensions (2D) by stacking horizontal DW chains in the vertical direction, we also create 2D multi-wave lattices. In such 2D lattices multiple Su–Schrieffer–Heeger (SSH) chains appear along the vertical direction. The combination of DW chains in the horizonal and SSH chains in the vertical direction then results in the formation of higher-order topological insulator corner states. Multistable corner states emerge in the nonlinear regime.}}, author = {{Schneider, Tobias and Gao, Wenlong and Zentgraf, Thomas and Schumacher, Stefan and Ma, Xuekai}}, issn = {{2192-8614}}, journal = {{Nanophotonics}}, number = {{4}}, pages = {{509--518}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates}}}, doi = {{10.1515/nanoph-2023-0556}}, volume = {{13}}, year = {{2024}}, }