arXiv subjects

Victoria Quiros-Cordero

Publications and source records attributed to Victoria Quiros-Cordero.

2 recordsLinked to original sources

arXiv2026

All-optical switching of nonlinear structured light in crystal-engineered van der Waals materials

The orbital angular momentum (OAM) of light is a discrete, unbounded degree of freedom that underpins mode-multiplexed communications and high-dimensional quantum photonics. Yet, dynamic OAM control remains dependent on bulky free-space optics or cascaded architectures that separate switching from wavefront shaping, hindering nanoscale integration. Here, we engineer artificial van der Waals crystals from rhombohedrally stacked (3R) MoS$_2$, in which spatial control of the local crystal orientation imprints a nonlinear geometric phase onto the second-harmonic (SH) field, enabling background-free generation of SH vortex beams in an ultrathin (46 nm) van der Waals platform. Leveraging the C$_{3v}$ symmetry of 3R-MoS$_2$, we demonstrate monolithic, all-optical switching with sub-optical-cycle precision between Hermite-Gauss-like and Laguerre-Gaussian vortex SH beams with opposite topological charges ($l=\pm1$). Our results establish artificial 3R-MoS$_2$ crystals as a monolithic platform for the generation and all-optical reconfiguration of nonlinear structured light at the nanoscale, advancing active nanophotonic sources for integrated classical and quantum photonic technologies.

physics.optics↗

arXiv2025

Nonlinear Dynamics in the Formation of Molecular Polariton Condensates

Exciton-polaritons - hybrid light-matter quasiparticles - can undergo Bose-Einstein-like condensation at elevated temperatures owing to their lower effective mass. This becomes even more pronounced in the context of molecular polariton condensates where the large exciton binding energy of Frenkel excitons facilitates condensation at room temperature. While widely studied as low-threshold coherent light sources, the dynamics of their condensation remain poorly understood, partly due to the limitations of existing kinetic models. Here, we use excitation correlation photoluminescence (ECPL), a nonlinear optical technique with 220fs resolution, to probe molecular polariton condensation in Rhodamine-B-doped small-molecule ionic isolation lattices (SMILES). This platform promotes dipole alignment and suppresses detrimental intermolecular interactions. ECPL reveals condensate formation within hundreds of femtoseconds, driven by radiative scattering from the reservoir. A sustained population beyond the polariton lifetime suggests an additional feeding mechanism from higher momentum states in the lower polariton dispersion. These results provide quantitative insight into condensation timescales and mechanisms, advancing our control over polariton dynamics.

cond-mat.mtrl-sci↗