Theory of enhanced energy transfer between molecules embedded in spherical dielectric particles

Abstract

The effects of morphological resonances on radiative emission rates and on dipole–dipole energy transfer rates between molecules embedded in aerosol droplets are studied by developing and applying a theory based on electromagnetic solutions for a dielectric sphere. Expressions for the Mie-resonance contributions to the transfer and emission rates are obtained in terms of the experimentally measurable spectral shape functions for the donor and acceptor molecules in the bulk host medium. Mie resonances in droplets of about 10 μm diameter are found to cause only minor changes in the integrated radiative rate, while strongly enhancing the rate and quantum efficiency of energy transfer. Estimates of the enhancement effect and calculations of its dependence on donor/acceptor location yield results consistent with experiment, supporting our interpretation that the observed energy–transfer enhancement occurs via Mie resonances of the nearly spherical droplets, and providing further insight into the Mie-enhanced energy–transfer mechanism.

Spherical whispering‐gallery‐mode microresonators

“…The total optical loss in such resonators can be extremely low, and the resulting extraordinary high Q values of 10 8 - 10 9 lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. Liquid microspheres can also be considered, and indeed early experiments studied WGMs and laser emission in liquid microdroplets flying in air [35][36][37][38][39]. Tzeng et al, for instance, introduced a new optical technique, based on morphology-dependent peaks in the fluorescence spectra, to determine the evaporation and condensation rates of a linear stream of ethanol droplets impregnated with fluorescent dye molecules [35].…”

Coherence retention by resonance dynamic dipole–dipole interaction among quantum dot ensemble for quantum computing

“…At the same time, the frequency should be sufficiently different from that of (π or π 2 ) optical pulses for the gates such as CN or CCN to avoid cross talks. The inter-block resonance Rabi oscillation may have dependence on the shape of the blocks and the shape of the space between them, as analogously expected from the case of Mie resonance in a micro-particle (enhancement at interfaces) [22].…”

Semiclassical scattering of an electric dipole source inside a spherical particle

“…[7][8][9] The exact solution to the related electromagnetic boundary-value problem of scattering by an arbitrarily positioned, arbitrarily oriented electric dipole source inside a spherical particle has also been derived. [10][11][12][13][14][15][16] This situation describes, for example, a liquid droplet containing molecules that fluoresce. Although scattering in the short-wavelength limit by a sphere containing an interior source has been computed by using both wave theory 17 and ray theory, [18][19][20][21][22] a detailed physical interpretation of the angular dependence of the scattered intensity has not been given.…”