Lifetime fluctuations of a single emitter in a disordered nanoscopic system: The influence of the transition dipole orientation

Abstract

We study the fluctuations of the fluorescence decay rate of a single emitter in a random cluster of nanoparticles, in a regime dominated by near‐field scattering. Configurational changes of the environment induce statistical changes of the decay rate. Two regimes are considered which differ in terms of transition dipole orientation. In one regime, the orientation of the transition dipole is assumed to remain constant while the configuration of the cluster changes randomly. In another regime, the orientation of the transition dipole is assumed unknown and continuously averaged over the three directions of space. Using exact numerical simulations and a simple analytical model, we show that the statistical distributions of the spontaneous decay rate are substantially different in both regimes. In both cases, the decay rate fluctuations are strongly dependent on the level of absorption at the nanoscale. We discuss the impact of this result in terms of imaging in complex media. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Electromagnetic field correlations in three-dimensional speckles

“…Indeed, LDOS fluctuations can be extremely sensitive to the microscopic structure of the disordered medium [95,108,109]. They carry information on length scales beyond the scattering mean free path, an important property for sensing or imaging in complex media.…”

“…[108,109]. As a model of a disordered medium, we consider a spherical region with radius R, filled with individual particles with radius a ≪ λ, where λ is the emission wavelength.…”

“…Simple explicit expressions can be obtained by keeping the leading terms in the calculation of the LDOS ρ(r s , ω) based on Eqs. (72) and (77) [108,109]. Using the simplified notations ρ = ρ(r s , ω) and ρ 0 = ρ 0 (ω), we obtain for the averaged value [112]:…”

Polarization time of unpolarized light

“…The contribution of this cross interference to two-photon absorption is proportional to I i tE i tE j t τ (see, e.g., Eqs. (19) and (20) in Ref. [33]).…”

“…Mapping the time-averaged polarization state of cosmic microwave background radiation has already provided us with new, groundbreaking information on the early universe, and the possibility of measuring dynamical characteristics of the polarization state of this radiation can open one more channel of information for further cosmological investigations. Further, the quantum-mechanical selection rules governing atomic and molecular transitions depend essentially on the polarization state of light [17,18], while the fluctuations in fluorescence emission of single emitters yield information on their nanoscopic environment [19]. The polarization time can also be used to characterize pulsed beams, such as Poincaré beams, in which the polarization can go through all possible states within each pulse [20], and beams created by cascade emission of pairs of orthogonally polarized photons by quantum dots [21].…”