Overview of Results:
Light-Matter Interaction in Quantum Dot-Mie-Resonator System:
Infrared photo-luminescence emission from Ge(Si) quantum dots coupled with collective Mie modes of silicon nanopillars was demonstrated, providing experimental evidence of light emission enhancement of quantum emitters applying collective Mie resonances in finite nanoresonators. The theory of coupled nanoresonators was developed and explained how the modes of the finite arrays represent high-Q collective states which emerge due to the coupling between the dipole modes of individual nanopillars.
- Published an article "Coupling of Germanium Quantum Dots with Collective Sub-radiant Modes of Silicon Nanopillar Arrays", V. Rutckaia et al., ACS Photonics, 2021, 8, 1, 209–217,
https://pubs.acs.org/doi/10.1021/acsphotonics.0c01319(si apre in una nuova finestra) Investigation of Nanostructures with Topological States:
Demonstrated the experimental realization of topological edge states in an array of silicon nanostructured waveguides and the coherent control of these states through adjusting the phase between degenerate modes. Showed that the topological properties of the structure can be manipulated by changing the wavelength of excitation, which determines not only the localization length but also the very existence of the topological edge mode. The hybrid nature of the topological modes is exploited for coherent control, which gives immediate access to their switching in real-time. Used third-harmonic generation (THG) process to visualize the field of bulk and edge states, which provided excellent spatial resolution to capture the finest details of the field distribution. The proposed strategy could be beneficial for other classes of topological meta-devices such as topological waveguides, cavities, and lasers. Overall, the results of this research contribute to the advancement of the field of topological photonics and have the potential to impact various areas of science and technology.
- Published an article Coherent control of topological states in an integrated waveguide lattice, A.O. Mikhin, V. Rutckaia et al., Nano Letters, 2023, 23 (6), 2094-2099,
https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.2c04182(si apre in una nuova finestra) Topological Properties of Extended Nanostructures:
The research on planar metasurfaces supporting intrinsically chiral quasibound states in the continuum resulted in the design, fabrication, and characterization of a metasurface that selectively couples to circular polarization of a chosen handedness, resulting in an optical Fano resonance. The resulting diffractive optics can efficiently deflect light exclusively within narrowband wavelength channels, making it suitable for augmented reality applications. The study also demonstrated the compatibility of this platform with geometric phase engineering, suggesting a pathway towards experimental demonstration of novel diffractive devices. Overall, this research has significant scientific impact and has potential applications in various fields, including optical modulators and refractive index sensors.
Thermo-Optical Bistability in Silicon Metasurfaces:
Realized thermo-optical bistability in a metasurface supporting high-Q bound states in the continuum. By varying the spectral detuning between the laser and mode frequency and changing the angle of incidence excitation, the optical response of the metasurface was modified, switching it from hysteretic response to optical discrimination regime. The varied radiative losses of quasi-bound states in the continuum allowed for the optimization of the width of the hysteresis loop, which corresponds to the regime of nonlinear critical coupling condition. The results demonstrate the potential of this technology for all-optical control of light and have implications for the field of nanophotonics and optical switching.
Exploitation and Dissemination of Results:
Educational Events and Schools Participation:
Active engagement in a multitude of online education events from 2020 to 2022 was demonstrated. Workshops and specialized photonics sessions such as the METANANO Summer School on Scattering problems in Photonics were participated in, where an accolade for the best poster was awarded. A diverse range of events, including the Lindau Sciathon, METANANO Summer School on Optical Biosensing, and the 27th International Workshop on “Single Molecule Spectroscopy and Super-resolution Microscopy”, were attended.
Dissemination and Communication:
Despite the challenges posed by the COVID-19 pandemic, a commitment to disseminating knowledge was shown. Participation was made in online conferences such as the Metamaterials Conference and the META 2022 in Spain, where an invited talk was given. Active participation was made in various online forums, including a Round Table Discussion on "Gender Diversity in Science", a DFG seminar for high-school students, and an article in the online magazine “Campus HALENSIS” was featured.
Publications:
Research work led to the publication of articles in esteemed journals like ACS Photonics and Nano Letters. Preparation for several other research articles is currently being done, reflecting the ongoing efforts in the field of photonics and metasurfaces.
In summary, both the absorption and dissemination of knowledge across diverse platforms were ensured, leading to the effective communication of findings and advancements in the realm of photonics and related fields.
