• Rituraj, Rituraj
• Ptitcyn, G.
• Alaee, R.
• Albooyeh, M.
• Karamanos, T.
• Lamprianidis, A. G.
• Rockstuhl, C.
• Tretyakov, Sergei
• Fan, S.

Abstract

We provide a theoretical description of light scattering by a spherical particle whose permittivity is modulated in time at twice the frequency of the incident light. Such a particle acts as a finite-sized photonic time crystal and, despite its sub-wavelength spatial extent, can host optical parametric amplification. Conditions of parametric Mie resonances in the sphere are derived. We show that time-modulated materials provide a route to tailor directional light amplification, qualitatively different from that in scatterers made from a gain media. We design two characteristic time-modulated spheres that simultaneously exhibit light amplification and desired radiation patterns, including those with zero backward and/or vanishing forward scattering. The latter sphere provides an opportunity for creating shadow-free detectors of incident light.

Topics

• impedance spectroscopy
• light scattering