@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{61250, author = {{Bennenhei, Christoph and Shan, Hangyong and Struve, Marti and Kunte, Nils and Eilenberger, Falk and Ohmer, Jürgen and Fischer, Utz and Schumacher, Stefan and Ma, Xuekai and Schneider, Christian and Esmann, Martin}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{8}}, pages = {{3046--3054}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Organic Room-Temperature Polariton Condensate in a Higher-Order Topological Lattice}}}, doi = {{10.1021/acsphotonics.4c00268}}, volume = {{11}}, year = {{2024}}, } @article{57815, author = {{Karzel, Marek and Samusev, Anton K. and Linnik, Tetiana L. and Littmann, Mario and Reuter, Dirk and Bayer, Manfred and Scherbakov, Alexey V. and Akimov, Andrey V.}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Polariton-Induced Transparency in Multiple Quantum Wells Probed by Time Domain Brillouin Scattering}}}, doi = {{10.1021/acsphotonics.4c01357}}, year = {{2024}}, } @article{49607, abstract = {{In this work, we utilize thin dielectric meta-atoms placed on a silver substrate to efficiently enhance and manipulate the third-harmonic generation. We theoretically and experimentally reveal that when the structural symmetry of the meta-atom is incompatible with the lattice symmetry of an array, some generalized nonlinear geometric phases appear, which offers new possibilities for harmonic generation control beyond the accessible symmetries governed by the selection rule. The underlying mechanism is attributed to the modified rotation of the effective principal axis of a dense meta-atom array, where the strong coupling among the units gives rise to a generalized linear geometric phase modulation of the pump light. Therefore, nonlinear geometric phases carried by third-harmonic emissions are the natural result of the wave-mixing process among the modes excited at the fundamental frequency. This mechanism further points out a new strategy to predict the nonlinear geometric phases delivered by the nanostructures according to their linear responses. Our design is simple and efficient and offers alternatives for the nonlinear meta-devices that are capable of flexible photon generation and manipulation.}}, author = {{Liu, Bingyi and Geromel, René and Su, Zhaoxian and Guo, Kai and Wang, Yongtian and Guo, Zhongyi and Huang, Lingling and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Biotechnology, Electronic, Optical and Magnetic Materials}}, number = {{12}}, pages = {{4357--4366}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Nonlinear Dielectric Geometric-Phase Metasurface with Simultaneous Structure and Lattice Symmetry Design}}}, doi = {{10.1021/acsphotonics.3c01163}}, volume = {{10}}, year = {{2023}}, } @article{55901, author = {{Grisard, Stefan and Trifonov, Artur V. and Rose, Hendrik and Reichhardt, Rilana and Reichelt, Matthias and Schneider, Christian and Kamp, Martin and Höfling, Sven and Bayer, Manfred and Meier, Torsten and Akimov, Ilya A.}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{9}}, pages = {{3161--3170}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Temporal Sorting of Optical Multiwave-Mixing Processes in Semiconductor Quantum Dots}}}, doi = {{10.1021/acsphotonics.3c00530}}, volume = {{10}}, year = {{2023}}, } @article{45596, abstract = {{Dielectric metasurfaces provide a unique platform for efficient harmonic generation and optical wavefront manipulation at the nanoscale. Tailoring phase and amplitude of a nonlinearly generated wave with a high emission efficiency using resonance-based metasurfaces is a challenging task that often requires state-of-the-art numerical methods. Here, we propose a simple yet effective approach combining a sampling method with a Monte Carlo approach to design the third-harmonic wavefront generated by all-dielectric metasurfaces composed of elliptical silicon nanodisks. Using this approach, we theoretically demonstrate the full nonlinear 2π phase control with a uniform and highest possible amplitude in the considered parameter space, allowing us to design metasurfaces operating as third harmonic beam deflectors capable of steering light into a desired direction with high emission efficiency. The TH beam deflection with a record calculated average conversion efficiency of 1.2 × 10–1 W–2 is achieved. We anticipate that the proposed approach will be widely applied as alternative to commonly used optimization algorithms with higher complexity and implementation effort for the design of metasurfaces with other holographic functionalities.}}, author = {{Hähnel, David and Förstner, Jens and Myroshnychenko, Viktor}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{tet_topic_meta}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Efficient Modeling and Tailoring of Nonlinear Wavefronts in Dielectric Metasurfaces}}}, doi = {{10.1021/acsphotonics.2c01967}}, year = {{2023}}, } @article{30195, abstract = {{While plasmonic particles can provide optical resonances in a wide spectral range from the lower visible up to the near-infrared, often, symmetry effects are utilized to obtain particular optical responses. By breaking certain spatial symmetries, chiral structures arise and provide robust chiroptical responses to these plasmonic resonances. Here, we observe strong chiroptical responses in the linear and nonlinear optical regime for chiral L-handed helicoid-III nanoparticles and quantify them by means of an asymmetric factor, the so-called g-factor. We calculate the linear optical g-factors for two distinct chiroptical resonances to −0.12 and –0.43 and the nonlinear optical g-factors to −1.45 and −1.63. The results demonstrate that the chirality of the helicoid-III nanoparticles is strongly enhanced in the nonlinear regime.}}, author = {{Spreyer, Florian and Mun, Jungho and Kim, Hyeohn and Kim, Ryeong Myeong and Nam, Ki Tae and Rho, Junsuk and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Biotechnology, Electronic, Optical and Magnetic Materials}}, number = {{3}}, pages = {{784–792}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Second Harmonic Optical Circular Dichroism of Plasmonic Chiral Helicoid-III Nanoparticles}}}, doi = {{10.1021/acsphotonics.1c00882}}, volume = {{9}}, year = {{2022}}, } @article{31937, author = {{Li, Yao and Ma, Xuekai and Hatzopoulos, Zaharias and Savvidis, Pavlos G. and Schumacher, Stefan and Gao, Tingge}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{6}}, pages = {{2079--2086}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Switching Off a Microcavity Polariton Condensate near the Exceptional Point}}}, doi = {{10.1021/acsphotonics.2c00288}}, volume = {{9}}, year = {{2022}}, } @article{21360, author = {{Luk, Samuel M. H. and Vergnet, Hadrien and Lafont, Ombline and Lewandowski, Przemyslaw and Kwong, Nai H. and Galopin, Elisabeth and Lemaitre, Aristide and Roussignol, Philippe and Tignon, Jérôme and Schumacher, Stefan and Binder, Rolf and Baudin, Emmanuel}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, pages = {{449--454}}, title = {{{All-Optical Beam Steering Using the Polariton Lighthouse Effect}}}, doi = {{10.1021/acsphotonics.0c01962}}, year = {{2021}}, } @article{21475, author = {{Frese, Daniel and Wei, Qunshuo and Wang, Yongtian and Cinchetti, Mirko and Huang, Lingling and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{4}}, pages = {{1013--1019}}, title = {{{Nonlinear Bicolor Holography Using Plasmonic Metasurfaces}}}, doi = {{10.1021/acsphotonics.1c00028}}, volume = {{8}}, year = {{2021}}, } @article{63038, author = {{Sistani, Masiar and Bartmann, Maximilian G. and Güsken, Nicholas Alexander and Oulton, Rupert F. and Keshmiri, Hamid and Luong, Minh Anh and Momtaz, Zahra Sadre and Den Hertog, Martien I. and Lugstein, Alois}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{7}}, pages = {{1642--1648}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Plasmon-Driven Hot Electron Transfer at Atomically Sharp Metal–Semiconductor Nanojunctions}}}, doi = {{10.1021/acsphotonics.0c00557}}, volume = {{7}}, year = {{2020}}, } @article{59495, author = {{Güsken, Nicholas Alexander and Lauri, Alberto and Li, Yi and Matsui, Takayuki and Doiron, Brock and Bower, Ryan and Regoutz, Anna and Mihai, Andrei and Petrov, Peter K. and Oulton, Rupert F. and Cohen, Lesley F. and Maier, Stefan A.}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{4}}, pages = {{953--960}}, publisher = {{American Chemical Society (ACS)}}, title = {{{TiO2–x-Enhanced IR Hot Carrier Based Photodetection in Metal Thin Film–Si Junctions}}}, doi = {{10.1021/acsphotonics.8b01639}}, volume = {{6}}, year = {{2019}}, } @article{4342, author = {{Chen, Shumei and Rahmani, Mohsen and Li, King Fai and Miroshnichenko, Andrey and Zentgraf, Thomas and Li, Guixin and Neshev, Dragomir and Zhang, Shuang}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{5}}, pages = {{1671--1675}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Third Harmonic Generation Enhanced by Multipolar Interference in Complementary Silicon Metasurfaces}}}, doi = {{10.1021/acsphotonics.7b01423}}, volume = {{5}}, year = {{2018}}, } @article{1430, author = {{Hoffmann, Sandro P. and Albert, Maximilian and Weber, Nils and Sievers, Denis and Förstner, Jens and Zentgraf, Thomas and Meier, Cedrik}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{tet_topic_phc}}, pages = {{1933--1942}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Tailored UV Emission by Nonlinear IR Excitation from ZnO Photonic Crystal Nanocavities}}}, doi = {{10.1021/acsphotonics.7b01228}}, volume = {{5}}, year = {{2018}}, } @article{9514, author = {{Huang, Lingling and Song, Xu and Reineke, Bernhard and Li, Tianyou and Li, Xiaowei and Liu, Juan and Zhang, Shuang and Wang, Yongtian and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, pages = {{338--346}}, title = {{{Volumetric Generation of Optical Vortices with Metasurfaces}}}, doi = {{10.1021/acsphotonics.6b00808}}, year = {{2017}}, } @article{1461, author = {{Mühlenbernd, Holger and Georgi, Philip and Pholchai, Nitipat and Huang, Lingling and Li, Guixin and Zhang, Shuang and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, number = {{1}}, pages = {{124--129}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Amplitude- and Phase-Controlled Surface Plasmon Polariton Excitation with Metasurfaces}}}, doi = {{10.1021/acsphotonics.5b00536}}, volume = {{3}}, year = {{2015}}, } @article{4335, abstract = {{We explore the impact of ∼500 MHz surface acoustic waves traveling across a commensurable plasmonic grating coupler. A stroboscopic technique involving surface acoustic waves synchronized to a modelocked optical source allows to time-resolve the dynamical impact of the electromechanically induced perturbation. The surface acoustic wave periodically enhances or decreases the surface ripple of the static grating. Most remarkably, the dynamic surface deformation deliberately modulates the coupler’s efficiency by ±2% during the ∼2 ns acoustic cycle.}}, author = {{Ruppert, Claudia and Förster, Frederike and Zrenner, Artur and Kinzel, Jörg B. and Wixforth, Achim and Krenner, Hubert J. and Betz, Markus}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{nanomechanics, plasmonics, surface acoustic waves, surface plasmon polaritons}}, number = {{2}}, pages = {{91--95}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Radio Frequency Electromechanical Control over a Surface Plasmon Polariton Coupler}}}, doi = {{10.1021/ph400022u}}, volume = {{1}}, year = {{2014}}, }