Self-consistent quantum field theory for the characterization of complex random media by short laser pulses

Abstract

We present a quantum field theoretical method for the characterization of disordered complex media with short laser pulses in an optical coherence tomography setup (OCT). We solve this scheme of coherent transport in space and time with weighted essentially non-oscillatory methods (WENO). WENO is preferentially used for the determination of highly non-linear and discontinuous processes including interference effects and phase transitions like Anderson localization of light. The theory determines spatio-temporal characteristics of the scattering mean free path and the transmission cross section that are directly measurable in time-of-flight (ToF) and pump-probe experiments. The results are a measure of the coherence of multiple scattering photons in passive as well as in optically soft random media. Our theoretical results of ToF are instructive in spectral regions where material characteristics such as the scattering mean free path and the diffusion coefficient are methodologically almost insensitive to gain or absorption and to higher-order nonlinear effects. Our method is applicable to OCT and other advanced spectroscopy setups including samples of strongly scattering mono-and polydisperse complex nano-and microresonators.

Quantum Many-Body Theory for Exciton-Polaritons in Semiconductor Mie Resonators in the Non-Equilibrium

“…As such it may determine the Q-factor of the single Mie resonator in principle [48]; however, in the non-equilibrium regime and in the corresponding physical time range microscopic interactions in the sense of impurity scattering in the selvedge have no fundamental influence. The Mie resonance ofhω 0 = 2.45 eV corresponds to the wavelength λ = 505.34 nm [37]; effectively this whispering gallery is populated in the resonance by photons. Thus, the classical picture of the Mie resonance [49] of a sole geometric resonance of otherwise passive matter is replaced here by the Fano resonance [50] of the single mode with the continuum of excitons which is embedded in a Floquet matrix [28][29][30][31].…”

“…The sample is externally pumped in (111) direction. Mie resonances [37] occur at the inner cylinder jacket and they couple to the density of bulk states in the sense of a Fano resonance. We consider in this article the exciton and exciton polariton dynamics of the single scatterer as the building block of the solid state random laser or the polariton random laser.…”

Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler

“…Due to the transient simulation, the gas-solid mixing in the furnace was very complex, and a single instantaneous result could not well reflect the actual diffusion characteristics of the secondary air. Therefore, the diffusion characteristics of SA, gas-solid flow and material concentration profiles in this paper were investigated using the method of time average processing of instantaneous results [26,27].…”

Structure, Morphology, Heat Capacity, and Electrical Transport Properties of Ti3(Al,Si)C2 Materials

“…In view of good crystallinity of the materials, as revealed in the X-ray diffraction study, the electron carrier scattering at the lattice defects can be excluded as the dominant mechanism. Considering quasi two-dimensionality of the materials, the mechanism related to the Anderson localization should also be taken into account [44][45][46]. However, its verification is beyond the The magnetoresistance effect in a metal is approximately inversely proportional to the relaxation time of the electrical carriers, i.e., directly proportional to their mobility.…”