Transition from Phononic to Geometrical Mie Modes Measured in Single Subwavelength Polar Dielectric Spheres
نویسندگان
چکیده
Spherical dielectric resonators are highly attractive for light manipulation, thanks to their intrinsic electric and magnetic resonances. Here, we present measurements of the mid-infrared far-field thermal radiation single subwavelength spheres deposited on a gold substrate, radii ranging from 1 2.5 μm, which agree quantitatively with simulated absorption cross sections. For SiO2 microspheres, evidence excitation both surface phonon-polariton (SPhP) modes geometrical Mie modes. The transition phonon-mode-dominated Mie-mode-dominated emission spectrum is observed, threshold radius ∼1.5 μm. We also show that presence metallic substrate augments computed cross-section due increased local field enhancement, arising near-field interaction oscillating charges image in mirror. In contrast, SPhP-inactive PTFE reveal response such lossy dominated by bulk absorption. Our results demonstrate how engineering properties scatterers can enable control near room temperature, exciting perspectives applications as radiative cooling.
منابع مشابه
Deep subwavelength surface modes in metal-dielectric metamaterials.
We present what we believe to be the first study of deep subwavelength surface modes in binary metal-dielectric metamaterials. By employing anomalous coupling in binary periodicity, peculiar properties of band structure and eigenmode symmetry are obtained. We show that strongly confined plasmonic Tamm-like and Shockley-like surface modes can be formed at the termination of the array. We clarify...
متن کاملTime-Dependent Lorentz-Mie-Debye Formulation for Electromagnetic Scattering from Dielectric Spheres
Canonical solutions to frequency domain Maxwell’s equations, in the spherical coordinate system, have found extensive use as is evident from citations in the scientific literature. What is conspicuous by its absence is lack of such expressions for transient Maxwell systems. The existence of such expressions or approximations, provide the means to glean interesting physics in a variety of applic...
متن کاملTransmission properties of a single metallic slit: from the subwavelength regime to the geometrical-optics limit.
In this work we explore the transmission properties of a single slit in a metallic screen. We analyze the dependence of these properties on both slit width and angle of incident radiation. We study in detail the crossover between the subwavelength regime and the geometrical-optics limit. In the subwavelength regime, resonant transmission linked to the excitation of waveguide resonances is analy...
متن کاملMie resonances of dielectric spheres in face-centered cubic photonic crystals.
With use of plane waves as a basis for the band-structure calculation of a periodic assembly of highly refringent microspheres, it can be shown that resonance-mode frequencies of isolated dielectric spheres show up in the band structures. The strongly localized bands provided by the photonic-crystal analysis is compared with exact calculations made in spherical symmetry for an isolated microsph...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: ACS Photonics
سال: 2022
ISSN: ['2330-4022']
DOI: https://doi.org/10.1021/acsphotonics.2c00273