Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical review. B, Condensed matter

Generalized models for spectral transfer in disordered systems

David L. Huber, W. Y. Ching

Published Nov 15, 1978• 19 citations
Publisher

Abstract

We analyze the early-time development of the spectral transfer of optical excitation in inhomogeneously broadened systems. Previous models for the decay of the narrow-band fluorescence are generalized to include systems with asymmetric energy-dependent transfer rates. It is assumed that the energy splittings of the ions are uncorrelated. An analogous model for the early-time development of the background fluorescence is outlined. Detailed results are presented for spectral transfer over a Gaussian line shape assuming a dipole-dipole mechanism with rates that are inversely proportional to the square of the energy mismatch. Comparison is made with the treatment of Holstein et al.

DOI
10.1103/physrevb.18.5320

Related papers

Time development of the spectral redistribution in disordered systems with a Lorentzian transfer rate: Theoretical models and a Monte Carlo study

S. K. Lyo

The time-dependent spectral redistribution in fluorescence line narrowing in an inhomogeneously broadened system is investigated by means of simple theoretical models and Monte Carlo calculations. The two-site phonon-assisted energy transfer rate is assumed to be site-symmetric and a Lorentzian function of energy mismatch. For the Monte Carlo calculations initial excitations are made at the wing, shoulder, and center of the inhomogeneously broadened Gaussian band. For the wing excitation it is argued that, because of the above Lorentzian factor, the intensity in the initial site of excitation decays with a much smaller back-transfer rate than for the center excitation, simplifying the theoretical treatment. This effect is demonstrated by the Monte Carlo study. A refinement of this model is developed for a general situation, and its predictions are compared with the Monte Carlo results.

Physical review. B, Condensed matter•Oct 15, 1980•12 citations

Study of time-dependent spectral transfer in disordered systems

S. K. Lyo

We study the time development of spectral profile of an inhomogeneously broadened system of a low concentration of optically active random two-level impurity ions excited with a narrow-band laser pulse. The spectral transport is due to phonon-assisted spatial migration of optical excitations among the impurity ions. The basic two-site transfer rate is assumed to be site symmetric and independent of the energy levels of the initial and final sites when the thermal energy is much larger than the inhomogeneous width. A "direct transfer" model relevant to some current works is solved exactly for dipolar interaction at a low-impurity concentration. In this model transitions are allowed only between the initial site of excitation and rest of the ions. The result agrees well with a previous "exact" Monte Carlo calculation for a short time. The result is improved systematically for longer times by using a pair model, a 3-site model, and a 4-site model. In the first two models, energy transfer is allowed along one and two nearest-neighbor percolation bonds, respectively, starting from the initial site of excitation. In a 4-site model additional transfer is included between the initial ion and its second neighbor. Transitions to the background ions without back transfer are allowed in all cases. Finally, the theoretical results are compared with recent experimental data.

Physical review. B, Condensed matter•Aug 15, 1979•22 citations

Calculations of spectral transfer in disordered and low-dimensional systems

M C K Wiltshire

The time development of the spectral transfer of optical excitations in inhomogeneously broadened systems is investigated as a function of transfer range, concentration of optically active ions and the dimensionality of the system. The equation of motion method is employed to calculate the spin-wave density of states for the equivalent ferromagnet and this is transformed to obtain the time dependence of the narrow band fluorescence. It is found that neighbours out to the fifth shell in a simple cubic lattice are significant for dipole-dipole interactions. Reducing the effective dimensionality of the model leads to a considerably slower spectral redistribution of the fluorescence.

Journal of Physics C Solid State Physics•Apr 20, 1981•0 citations

Spectral-spatial diffusion in inhomogeneously broadened systems

Theodore D. Holstein, S. K. Lyo, R. Orbach

Most phonon-assisted spectral transfer rates across an inhomogeneously broadened line are proportional to the inverse square of the energy change. The time-dependent optical emission profile is calculated exactly for a rectangular line shape for these processes. Numerical solutions are required for other line shapes (e.g., a Gaussian as found in ruby). They are exhibited as a function of time for a variety of initial excitation energies at different positions across the optical line.

Physical review. B, Solid state•May 15, 1977•39 citations

Fluorescence Line Narrowing in Dilute Systems with Nearest-Neighbor Transfer

David L. Huber

We outline the results of an analysis of fluorescence line narrowing1 in dilute systems. We assume that a fraction, p, of the sites on a d-dimensional lattice are occupied at random by optically active ions and that the transfer of optical excitation can only take place between ions occupying nearest-neighbor sites. The normalized intensity of the sharp line fluorescence following excitation of an inhomogeneously broadened line by a monochromatic source is equal to exp [−γRt]<P(t)>, where γR is the radiative decay rate and <P(t)> is the probability that an ion excited at t=0 is also excited at time t.2

International Conference on Luminescence - 1984•Jan 1, 1984•0 citations

Concentration dependence of the fluorescent energy transfer

Moshe Fibich, David L. Huber

We analyze the time development of the sharp-line fluorescence in a time-resolved fluorescent-line-narrowing experiment. The optically active ions are distributed at random on a lattice. Symmetric transfer rates are assumed which are independent of the energy mismatch between ions. We discuss a systematic expansion of fluorescent intensity in powers of the concentration $c$ and present results for the ${c}^{2}$ term.

Physical review. B, Condensed matter•Dec 15, 1979•8 citations
We analyze the early-time development of the spectral transfer of optical excitation in inhomogeneously broadened systems. Previous models for the decay of the narrow-band fluorescence are generalized to include systems with asymmetric energy-dependent transfer rates. It is assumed that the energy splittings of the ions are uncorrelated. An analogous model for the early-time development of the background fluorescence is outlined. Detailed results are presented for spectral transfer over a Gaussian line shape assuming a dipole-dipole mechanism with rates that are inversely proportional to the square of the energy mismatch. Comparison is made with the treatment of Holstein et al.
The time-dependent spectral redistribution in fluorescence line narrowing in an inhomogeneously broadened system is investigated by means of simple theoretical models and Monte Carlo calculations. The two-site phonon-assisted energy transfer rate is assumed to be site-symmetric and a Lorentzian function of energy mismatch. For the Monte Carlo calculations initial excitations are made at the wing, shoulder, and center of the inhomogeneously broadened Gaussian band. For the wing excitation it is argued that, because of the above Lorentzian factor, the intensity in the initial site of excitation decays with a much smaller back-transfer rate than for the center excitation, simplifying the theoretical treatment. This effect is demonstrated by the Monte Carlo study. A refinement of this model is developed for a general situation, and its predictions are compared with the Monte Carlo results.
We study the time development of spectral profile of an inhomogeneously broadened system of a low concentration of optically active random two-level impurity ions excited with a narrow-band laser pulse. The spectral transport is due to phonon-assisted spatial migration of optical excitations among the impurity ions. The basic two-site transfer rate is assumed to be site symmetric and independent of the energy levels of the initial and final sites when the thermal energy is much larger than the inhomogeneous width. A "direct transfer" model relevant to some current works is solved exactly for dipolar interaction at a low-impurity concentration. In this model transitions are allowed only between the initial site of excitation and rest of the ions. The result agrees well with a previous "exact" Monte Carlo calculation for a short time. The result is improved systematically for longer times by using a pair model, a 3-site model, and a 4-site model. In the first two models, energy transfer is allowed along one and two nearest-neighbor percolation bonds, respectively, starting from the initial site of excitation. In a 4-site model additional transfer is included between the initial ion and its second neighbor. Transitions to the background ions without back transfer are allowed in all cases. Finally, the theoretical results are compared with recent experimental data.
The time development of the spectral transfer of optical excitations in inhomogeneously broadened systems is investigated as a function of transfer range, concentration of optically active ions and the dimensionality of the system. The equation of motion method is employed to calculate the spin-wave density of states for the equivalent ferromagnet and this is transformed to obtain the time dependence of the narrow band fluorescence. It is found that neighbours out to the fifth shell in a simple cubic lattice are significant for dipole-dipole interactions. Reducing the effective dimensionality of the model leads to a considerably slower spectral redistribution of the fluorescence.
We outline the results of an analysis of fluorescence line narrowing1 in dilute systems. We assume that a fraction, p, of the sites on a d-dimensional lattice are occupied at random by optically active ions and that the transfer of optical excitation can only take place between ions occupying nearest-neighbor sites. The normalized intensity of the sharp line fluorescence following excitation of an inhomogeneously broadened line by a monochromatic source is equal to exp [−γRt]<P(t)>, where γR is the radiative decay rate and <P(t)> is the probability that an ion excited at t=0 is also excited at time t.2
We analyze the time development of the sharp-line fluorescence in a time-resolved fluorescent-line-narrowing experiment. The optically active ions are distributed at random on a lattice. Symmetric transfer rates are assumed which are independent of the energy mismatch between ions. We discuss a systematic expansion of fluorescent intensity in powers of the concentration ccc and present results for the c2{c}^{2}c2 term.