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Mateusz Kędziora

Publications and source records attributed to Mateusz Kędziora.

7 recordsLinked to original sources

Optically trapped exciton-polariton condensates in a perovskite microcavity

We demonstrate room temperature optical trapping and generation of high-order angular harmonics in exciton-polariton condensates in a monocrystalline CsPbBr$_3$ perovskite-filled microcavity. Using an annular nonresonant excitation profile focused onto the perovskite, we observed power-driven switching between different transverse modes of the optically induced trap. We explore the interplay between the perovskite crystal dimensions and the optical trap diameter that allows the condensate to transition from whispering gallery-like petal shapes to extended ripple states. Our results underline the feasibility in creating high-order quantum states in perovskite polariton condensates for reconfigurable and structured room temperature nonlinear lasing.

physics.optics↗

Chiral polariton transport enabled by optical spin Hall effect in perovskite waveguides

Controlling the spin degree of freedom of light at the microscale is crucial for advancing photonic information processing. Spin polarized light propagation, combined with strong optical nonlinearities, unlocks new functionalities in compact photonic circuits and active spin optronic devices. Lead halide perovskite exciton polaritons uniquely combine room temperature operation, pronounced nonlinearities, and versatile microstructuring, making them a powerful platform for spin based photonic technologies. Here, we demonstrate polarized edge emission from polariton condensates in perovskite single crystals predesigned into a microwire, forming natural, DBR free cavity. Above threshold, we observe a distinct waveguiding optical spin Hall effect pattern in both real- and reciprocal-space emission, accompanied by pseudospin phase locking arising from coherence between opposite edges. Beyond static polarization textures, we achieve spin-resolved polariton edge lasing with chirality exceeding 80\% and spin-polarized signal propagation over tens of micrometres. These results establish CsPbBr3 waveguides as a promising easy to fabricate platform for on chip spin coded information transport and nonlinear spin optoelectronics.

cond-mat.other↗

Guided polariton condensate in perovskite microwires

Perovskite microwires are promising candidates for integrated photonic systems due to their strong nonlinear optical response and inherent waveguiding capabilities. In this study, we focus on the directional emission properties of exciton-polariton condensates formed within perovskite microwires, with emphasis on emission collected from the microwire end. We constructed a multi-angle optical detection setup that allows us to identify the exciton-polariton condensation threshold and track the evolution of the condensate for different excitation position along and across the microwire. We observe spectrally narrow exciton-polariton condensate emission from the microwire end even when the condensate is generated tens of micrometers away, which demonstrates the ability of the exciton-polariton condensate to propagate over long distances within the microwire. Furthermore, we find that the presence of structural defects near the condensate location can significantly enhance the emission from the microwire end due to aligning the condensate's momentum with the waveguide direction, thereby facilitating more efficient propagation.

physics.optics↗

Room temperature exciton-polariton neural network with perovskite crystal

Limitations of electronics have stimulated the search for novel unconventional computing platforms that enable energy-efficient and ultra-fast information processing. Among various systems, exciton-polaritons stand out as promising candidates for the realization of optical neuromorphic devices. This is due to their unique hybrid light-matter properties, resulting in strong optical nonlinearity and excellent transport capabilities. However, previous implementations of polariton neural networks have been restricted to cryogenic temperatures, limiting their practical applications. In this work, using non-equillibrium Bose-Einstein condensation in a monocrystalline perovskite waveguide, we demonstrate the first room-temperature exciton-polariton neural network. Its performance is verified in various machine learning tasks, including binary classification, and object detection. Our result is a crucial milestone in the development of practical applications of polariton neural networks and provides new perspectives for optical computing accelerators based on perovskites.

physics.optics↗

Non-Hermitian polariton-photon coupling in a perovskite open microcavity

Exploring the non-Hermitian properties of semiconductor materials for optical applications is at the forefront of photonic research. However, the selection of appropriate systems to implement such photonic devices remains a topic of debate. In this work, we demonstrate that a perovskite crystal, characterized by its easy and low-cost manufacturing, when placed between two distributed Bragg reflectors with an air gap, can form a natural double microcavity. This construction shows promising properties for the realisation of novel, tunable non-Hermitian photonic devices through strong light-matter coupling. We reveal that such a system exhibits double-coupled polariton modes with dispersion including multiple inflection points. Owing to its non-Hermiticity, our system exhibits nonreciprocal properties and allows for the observation of exceptional points. Our experimental studies are in agreement with the theoretical analysis based on coupled mode theory and calculations based on transfer matrix method.

cond-mat.mes-hall↗

Non-Hermitian synthetic lattices with light-matter coupling

We propose that light-matter coupling can be used to realize synthetic lattices. In particular, we consider a one-dimensional chain of exciton-photon sites to create a comb lattice that exhibits a transition from a flat band to a finite mass dispersion by tuning site-dependent light-matter coupling. Moreover, in a non-Hermitian system with gain and loss, the flat band phase is much more robust and the transition is accompanied by the appearance of exceptional points in the complex energy spectrum. We demonstrate that by engineering the light-matter coupling in the synthetic lattice, one can explore various phases in the lasing regime. Our proposal paves the way for studying non-Hermitian systems in higher dimensions.

cond-mat.mes-hall↗

Lasing in the Rashba-Dresselhaus spin-orbit coupling regime in a dye-filled liquid crystal optical microcavity

In the presence of Rashba-Dresselhaus coupling, strong spin-orbit interactions in liquid crystal optical cavities result in a distinctive spin-split entangled dispersion. Spin coherence between such modes give rise to an optical persistent-spin-helix. In this letter, we introduce optical gain in such a system, by dispersing a molecular dye in a liquid-crystal microcavity. We demonstrate both lasing in the Rashba-Dresselhaus regime and the emergence of an optical persistent spin helix.

physics.optics↗