Highlighted authors are members of the University of Jena.
Deterministic Fabrication of Fluorescent Nanostructures Featuring Distinct Optical Transitions
Year of publicationPublished in:Nanomaterials
M. Rikers, A. Bashiri, G. Angela, M. Steinert, D. Choi, T. Pertsch, I. Staude
The precise and deterministic integration of fluorescent emitters with photonic nanostructures is an important challenge in nanophotonics and key to the realization of hybrid photonic systems, supporting effects such as emission enhancement, directional emission, and strong coupling. Such integration typically requires the definition or immobilization of the emitters at defined positions with nanoscale precision. While various methods were already developed for creating localized emitters, in this work we present a new method for the deterministic fabrication of fluorescent nanostructures featuring well-defined optical transitions; it works with a minimal amount of steps and is scalable. Specifically, electron-beam lithography is used to directly pattern a mixture of the negative-tone electron-beam resist with the europium complex Eu(TTA)₃, which exhibits both electric and magnetic dipolar transitions. Crucially, the lithography process enables precise control over the shape and position of the resulting fluorescent structures with a feature size of approx. 100 (Formula presented.) (Formula presented.). We demonstrate that the Eu(TTA)₃ remains fluorescent after exposure, confirming that the electron beam does not alter the structure the optical transitions. This work supports the experimental study of local density of optical states in nanophotonics. It also expands the knowledge base of fluorescent polymer materials, which can have applications in polymer-based photonic devices. Altogether, the presented fabrication method opens the door for the realization of hybrid nanophotonic systems incorporating fluorescent emitters for light-emitting dielectric metasurfaces.
Angle-Tolerant Circular Eigenpolarizations Enabled by Orientational Disorder in Dielectric Metasurfaces
Year of publicationPublished in:Advanced Optical Materials
K. Tanaka, A. Rahimzadegan, D. Arslan, A. Fitriana, S. Fasold, D. Pidgayko, M. Steinert, T. Pertsch, M. Decker, C. Rockstuhl, I. Staude
Tailored structural disorder in photonic metasurfaces enables advanced light shaping. Specifically, an orientational disorder in chiral nanostructures leads to circular eigenpolarizations with a heavily suppressed linear birefringence. The orientational disorder is, therefore, vital to observing purely chiroptical effects such as circular dichroism and optical activity. Here, it is experimentally and numerically demonstrated that all-dielectric orientationally disordered chiral bilayer square array metasurfaces preserve highly circular eigenpolarizations for a wide range of incidence angles. The angle-dependent performance of disordered chiral metasurfaces is compared with that of their C₂ and C₄ symmetric periodic counterparts, demonstrating that the disordered structures provide nearly pure circular eigenpolarizations across a larger range of angles and wavelengths, whereas the periodic ones do not. These findings underscore the ability of tailored disorder to enhance the robustness of engineered chiroptical responses of all-dielectric metasurfaces and highlight its potential for flat, integrable, and highly efficient optical components, such as circular polarizers and beam splitters.
Angle-Tolerant Circular Eigenpolarizations Enabled by Orientational Disorder in Dielectric Metasurfaces
Year of publicationPublished in:Advanced Optical Materials
K. Tanaka, A. Rahimzadegan, D. Arslan, A. Fitriana, S. Fasold, D. Pidgayko, M. Steinert, T. Pertsch, M. Decker, C. Rockstuhl, I. Staude
Tailored structural disorder in photonic metasurfaces enables advanced light shaping. Specifically, an orientational disorder in chiral nanostructures leads to circular eigenpolarizations with a heavily suppressed linear birefringence. The orientational disorder is, therefore, vital to observing purely chiroptical effects such as circular dichroism and optical activity. Here, it is experimentally and numerically demonstrated that all-dielectric orientationally disordered chiral bilayer square array metasurfaces preserve highly circular eigenpolarizations for a wide range of incidence angles. The angle-dependent performance of disordered chiral metasurfaces is compared with that of their C₂ and C₄ symmetric periodic counterparts, demonstrating that the disordered structures provide nearly pure circular eigenpolarizations across a larger range of angles and wavelengths, whereas the periodic ones do not. These findings underscore the ability of tailored disorder to enhance the robustness of engineered chiroptical responses of all-dielectric metasurfaces and highlight its potential for flat, integrable, and highly efficient optical components, such as circular polarizers and beam splitters.
Fabrication of low-loss lithium niobate on insulator waveguides on the wafer scale [Invited]
Year of publicationPublished in:Optical Materials Express
M. Younesi, T. Kasebier, I. Elmanov, Y. Li, P. Kumar, R. Geiss, T. Siefke, F. Eilenberger, F. Setzpfandt, U. Zeitner, T. Pertsch
We report on the wafer scale fabrication of single-mode low-loss lithium niobate on insulator waveguides utilizing a chemically amplified resist and an optimized dry etching method. The fabricated single-mode waveguides are free of residuals and re-deposition, with measured losses for straight waveguides around 2 dB/m (0.02 dB/cm). We present a method offering advantages for large-scale production mainly due to its cost-effectiveness and faster writing time. This work holds promise for advancing integrated photonics and optical communication technologies.
Year of publicationStatusReview pendingPublished in:Optical Fiber Communication Conference in Proceedings Optical Fiber Communication Conference, OFC 2025 and Optical Fiber Communication Conference (OFC) Postdeadline Papers 2025
J. Schmid, P. Cheben, J. Zhang, R. Korček, M. Saad-Bin-Alam, R. Cheriton, S. Janz, D. Xu, S. Wang, M. Vachon, R. Ma, R. Halir, G. Wangüemert-Pérez, A. Ortega-Moñux, I. Molina Fernandez, A. Sánchez-Postigo, J. Luque-González, A. Hinestrosa, D. Melati, Z. Mokeddem, C. Alonso-Ramos, L. Vivien, W. Ye, S. Khajavi, W. Fraser, D. Benedikovic, Y. Sırmacı, I. Staude, T. Pertsch, C. Naraine, J. Bradley, A. Knights, T. Dominguez Bucio, F. Gardes
Momentum-Space Tunable Metasurfaces for Switchable Image Processing
Year of publicationStatusReview pendingPublished in:Advanced Optical Materials
K. Zhang, S. Wang, J. Qiu, M. Yang, T. Liu, S. Xiao, I. Staude, T. Pertsch, Y. Wang, C. Zou
Enhanced Exciton-Plasmon Interaction Enabling Observation of Near-Field Photoluminescence in a WSe₂-Gold Nanoparticle Hybrid System
Year of publicationStatusReview pendingPublished in:ACS Photonics
A. Romashkina, S. Sushil, A. Barreda, Z. Fedorova, F. Abtahi, N. Doolaard, Z. Zhang, C. Helgert, I. Staude, F. Eilenberger, T. Pertsch, B. Tugchin
Monolayer transition metal dichalcogenides, such as tungsten diselenide, have recently attracted considerable attention due to their reduced dielectric screening and direct bandgap, which result in high exciton binding energy and strong photoluminescence. The integration of monolayer transition metal dichalcogenides with plasmonic nanoparticles enhances their optoelectronic properties through localized surface plasmons and strong electromagnetic confinement. We investigated the photoluminescence response of the hybrid system of monolayer tungsten diselenide and gold nanoparticle arrays through near-field mapping. Our study demonstrated a significant enhancement of the excitonic emission by the excited gold nanoparticles via near-field interaction. We examined the impact of exciton-plasmon-polariton coupling on the far-field response of the hybrid system. There, we observed the phenomenon of exciton-induced transparency, which indicates the intermediate coupling regime and helps resonantly enhance the light-matter interaction in monolayer tungsten diselenide. The second harmonic generation intensity from the hybrid system was shown to follow the linear spectral response of the hybrid system, thereby demonstrating the enhanced coupling between surface plasmons and excitons. Our research offers insights into the impact of intermediate coupling on the optical properties of hybrid exciton-plasmon systems, which is crucial for the development of advanced nanophotonic devices.
Spatially Controlled All-Optical Switching of Liquid-Crystal-Empowered Metasurfaces
Year of publicationStatusReview pendingPublished in:ACS Photonics
M. Beddoe, S. Walden, S. Miljevic, D. Pidgayko, C. Zou, A. Minovich, A. Barreda, T. Pertsch, I. Staude
Embedding metasurfaces in liquid crystal (LC) cells is a promising technique for realizing tunable optical functionalities. Here, we demonstrate spatially controlled all-optical switching of the optical response of a homogeneous silicon nanocylinder metasurface featuring various Mie-type resonances in the spectral range between 670 and 720 nm integrated in a nematic LC cell. The initial alignment of the LC molecules is controlled by photoalignment layers, where the alignment direction is defined by homogeneous exposure with linearly polarized light at a 450 nm wavelength. Exposure of the photoalignment layer with the same light, whose polarization is rotated by 90°, induces a local change in the direction of the LC alignment and modulates the optical response of the metasurface. The resulting spatially dependent optical properties of the metasurface system are characterized by hyperspectral imaging. The described technique allows the nonvolatile creation of complex spatio-spectral response functions with a spatial resolution of 20 μm. Moreover, we demonstrate that the response of the LC-integrated metasurface can be switched multiple times by subsequent exposures with alternating orthogonal polarizations. Finally, we show that the images can be temporarily erased by heating the sample above the critical LC transition temperature, where the LC transitions to its isotropic phase. The demonstrated approach represents the controlling-light-by-light concept, an alternative to electro-optical or electromechanical control methods, which require complicated electronic architectures for spatially resolved modulation. Our results hold significant potential for applications such as next-generation displays or spatial light modulators that require spatial control of a tunable, tailored optical response.
Femtosecond Pulse Shaping with Semiconductor Huygens' Metasurfaces
Year of publicationStatusReview pendingPublished in:Advanced Optical Materials
K. Tanaka, D. Arslan, M. Weissflog, N. Geib, K. Gerold, A. Szeghalmi, M. Ziegler, F. Eilenberger, T. Pertsch, R. Schiek, I. Staude
In situ spontaneous emission control of MoSe₂-WSe₂ interlayer excitons with high quantum yield
Year of publicationPublished in:Photonics Research
B. Han, C. Palekar, F. Lohof, S. Stephan, V. Mitryakhin, J. Drawer, A. Steinhoff, L. Lackner, M. Silies, B. Rosa, M. Esmann, F. Eilenberger, C. Gies, S. Reitzenstein, C. Schneider
Infrared Magnetopolaritons in MoTe2 Monolayers and Bilayers
Year of publicationPublished in:Physical Review Letters
B. Han, J. Fitzgerald, L. Lackner, R. Rosati, M. Esmann, F. Eilenberger, T. Taniguchi, K. Watanabe, M. Syperek, E. Malic, C. Schneider
MoTe2 monolayers and bilayers are unique within the family of van der Waals materials since they pave the way toward atomically thin infrared light-matter quantum interfaces, potentially reaching the important telecommunication windows. Here, we report emergent exciton polaritons based on MoTe2 monolayers and bilayers in a low-temperature open microcavity in a joint experiment-theory study. Our experiments clearly evidence both the enhanced oscillator strength and enhanced luminescence of MoTe2 bilayers, signified by a 38% increase of the Rabi splitting and a strongly enhanced relaxation of polaritons to low-energy states. The latter is distinct from polaritons in MoTe2 monolayers, which feature a bottlenecklike relaxation inhibition. Both the polaritonic spin valley locking in monolayers and the spin-layer locking in bilayers are revealed via the Zeeman effect, which we map and control via the light-matter composition of our polaritonic resonances.
Photoluminescence-based gas sensing with MoS₂ monolayers
Year of publicationStatusReview pendingPublished in:Optics Express
G. Ngo, C. Cholsuk, S. Thiele, Z. Gan, A. George, J. Pezoldt, A. Turchanin, T. Vogl, F. Eilenberger