Browsing by Author "Lamprianidis, A. G."

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  • Expanding momentum bandgaps in photonic time crystals through resonances
    (2024-11-12) Wang, X; Garg, P.; Mirmoosa, M. S.; Lamprianidis, A. G.; Rockstuhl, C.; Asadchy, V. S.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The realization of photonic time crystals is a major opportunity but also comes with considerable challenges. The most pressing one, potentially, is the requirement for a substantial modulation strength in the material properties to create a noticeable momentum bandgap. Reaching that noticeable bandgap in optics is highly demanding with current, and possibly also future materials platforms because their modulation strength is small by tendency. Here we demonstrate that by introducing temporal variations in a resonant material, the momentum bandgap can be drastically expanded with modulation strengths in reach with known low-loss materials and realistic laser pump powers. The resonance can emerge from an intrinsic material resonance or a suitably spatially structured material supporting a structural resonance. Our concept is validated for resonant bulk media and optical metasurfaces and paves the way towards the first experimental realizations of photonic time crystals.
  • Mie Resonances and Kerker Effects in Parametric Time-Modulated Spheres
    (2022) Asadchy, V.; Lamprianidis, A. G.; Ptitcyn, G.; Albooyeh, M.; Rituraj; Karamanos, T.; Alaee, R.; Tretyakov, S. A.; Rockstuhl, C.; Fan, S.
     A4 Artikkeli konferenssijulkaisussa
    We provide a theoretical description of light scattering by a spherical particle whose permittivity is modulated with twice the frequency of the incident light. Such a sphere acts as a finite-size photonic time crystal and permits optical parametric amplification. We show that the control of the temporal modulation strength provides a qualitatively new route to spectrally overlap different parametric Mie resonances in the sphere for controlling its far-field pattern and satisfying the Kerker scattering conditions.
  • Unleashing Infinitely Wide Momentum Bandgaps in Photonic Time Crystals
    (2023) Wang, Xuchen; Garg, P.; Lamprianidis, A. G.; Mirmoosa, M. S.; Asadchy, V.; Rockstuhl, C.
     A4 Artikkeli konferenssijulkaisussa
    The emergence of photonic time crystals has engendered considerable scientific curiosity, owing to their unique features, including the momentum bandgaps. However, the generation of experimentally detectable momentum bandgaps poses a formidable challenge, particularly at high frequencies, necessitating the use of high-power pumping that may lead to deleterious material overheating. To tackle this problem, we propose two routes toward theoretically unlimited enhancement of the momentum bandgap size.