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

Applied Physics Letters

ON THE PROPERTIES OF THE SPECTRAL BLEACHING IN SATURABLE DYES

Vittorio Degiorgio

Published Mar 15, 1967• 9 citations
Publisher

Abstract

It is shown by a rate-equation analysis why hole-burning effects in the absorption line of some organic dyes have been observed only when the saturable absorber is within a laser cavity. The main assumption is that the absorption line is inhomogeneously broadened and that the cross relaxation time between homogeneous components is short compared to the spontaneous decay time, but still finite. An approximate value of the cross relaxation time is also calculated.

DOI
10.1063/1.1754899

Related papers

WAVE INTERACTIONS IN SATURABLE ABSORBERS

S. E. Schwarz, Teng Yong Tan

The interaction between waves in an idealized saturable absorber is discussed. It is shown that the presence of a strong wave will cause the line to appear to be ``hole-burned'' when probed by a second wave, even though the broadening mechanisms are conventionally homogeneous. This effect would be expected to work against the tendency of dye-switched ruby lasers to operate in a single mode. Related effects should play a role in optical pulse generators and in other devices using saturable absorbers.

Applied Physics Letters•Jan 1, 1967•116 citations

Effect of Spectral Hole-Burning and Cross Relaxation on the Gain Saturation of Laser Amplifiers

Amado Y. Cabezas, Richard P. Treat

A theory is presented for the effect of cross relaxation (CR) on the saturation with driving-signal intensity of the steady-state gain of a laser amplifier with an inhomogeneously broadened linewidth. The condition of steady-state gain results when the amplifier excitation level W and the driving-signal intensity are constant for about 3τ or longer, where τ is the fluorescence lifetime of the upper laser level. The driving signal is derived from an oscillator operated in the normal mode and which does not saturate the amplifier inversion density over times short compared with τ. We assume that CR, at a rate F, restores to thermal equilibrium any distortion of the spectral inversion density caused by the driving signal. Formulas are derived for steady-state gain saturation with arbitrary F for two cases: the spectral width of the driving signal is (1) narrow and (2) broad relative to the ionic or homogeneous line. The ionic linewidth Δvi is assumed to be much less than the inhomogeneous linewidth Δva and refers to the minimum frequency interval for which infinitely fast CR is operative. The theory also yields the CR coefficients f=(Δvi/Δva) [F/(τ−1+W)] for the narrow-band case and f*=(Δvs/Δva) [F/(τ−1+W)] for the broadband case, where Δvs is the driving-signal bandwidth. These coefficients significantly parametrize the CR effect: for f, f*>1, hole-burning is not severe, whereas for f, f*<1, considerable hole-burning takes place and the gain saturates faster. Finally, the theory is applied to experimental results obtained for Nd3+:glass broadband and narrow-band amplification; an approximate lower bound of 4×105 sec−1 is determined for F.

Journal of Applied Physics•Aug 1, 1966•58 citations

Analysis on width of burning hole in inhomogeneously broadened laser medium

Geguo Du

A detailed calculation about width of the burning hole in saturation behavior of inhomogeneously broadened laser medium is presented.The width of the burning hole is determined by the linewidth of homogeneous broadening because of the finite lifetime of the excited state due to spontaneous emission.

College Physics•Jan 1, 2005•1 citation

Effects of spectral cross relaxation and collisional dephasing on the absorption of light by organic-dye solutions

David W. Vahey, Amnon Yariv

The nonlinear absorption of intense laser light is used to obtain information about the times required for spectral cross relaxation (${T}_{3}$) and collisional dephasing (${T}_{2}$) in organic-dye solutions. The steady-state transmission experiment of Huff and DeShazer indicates that ${T}_{2}$ is in the range 0.1-1 psec for cryptocyanine-methanol, while ${T}_{3}$ is in the range 1-10 psec. For DDI-glycerin (1, 1\ensuremath{'}-diethyl-2, 2\ensuremath{'}-dicarbocyanine-iodide-glycerin), measurements of ultrashort-pulse transmission as a function of incident energy and optical polarization suggest a value ${T}_{2}=0.4\ifmmode\pm\else\textpm\fi{}0.2$ psec for that system. These results are based on a new set of rate equations for absorption by inhomogeneously broadened organic-dye solutions. The equations display the effects of spectral cross relaxation and are not limited to light intensities less than those at which coherent interaction effects become important. For the case of ultrashort incident pulses, the equations are extended to account for excited-state absorption, the dependence of absorption on optical polarization, and the existence of a multiplicity of interacting excited states.

Physical Review A•Nov 1, 1974•25 citations

Theory of transient hole-burning spectrum for molecules in solution

Shuichi Kinoshita

Theory based on a configuration coordinate model is presented to clarify solute–solvent relaxation effect on the line shape of a time-resolved hole-burning spectrum. The time-resolved hole-burning spectrum is affected by both a hole created in a ground-state population and an excess excited-state population. The solute–solvent relaxation causes thermalization in both populations and then the shift and broadening of the spectrum is expected observable. The line shapes of three typical cases are mainly considered: (1) The excited state is assumed to have an infinitely long lifetime; (2) the excited state has a finite lifetime, the population being assumed to relax toward an electronic state other than the ground state, and (3) the population created in the excited state relaxes to the ground state, where a hole-filling effect is taken into account. Results obtained by numerical calculations show that a time evolution of the ground-state hole is clearly observed when the low-energy tail of the absorption band is excited under the condition that the population decay to the other electronic state is very fast. Further, it is predicted that the hole-filling effect causes a considerable deformation of the spectral shape when the solvent relaxation rate is comparable to the excited-state population decay rate.

The Journal of Chemical Physics•Nov 1, 1989•60 citations

Pulse saturation behavior of inhomogeneously broadened lines. I. Slow spectral diffusion case

Jean‐Pierre Korb, J. Maruani

A model involving several coupled thermodynamic reservoirs is used to describe the behavior of inhomogeneously broadened absorption and dispersion signals under resonant and non-resonant stationary weak-pulse saturation. This model allows a good reproduction of the hole-burning and dipolar-reservoir effects observed on absorption lines and predicts similar, as yet unobserved, effects for dispersion signals.

Physical review. B, Condensed matter•Feb 1, 1981•14 citations
It is shown by a rate-equation analysis why hole-burning effects in the absorption line of some organic dyes have been observed only when the saturable absorber is within a laser cavity. The main assumption is that the absorption line is inhomogeneously broadened and that the cross relaxation time between homogeneous components is short compared to the spontaneous decay time, but still finite. An approximate value of the cross relaxation time is also calculated.
The interaction between waves in an idealized saturable absorber is discussed. It is shown that the presence of a strong wave will cause the line to appear to be ``hole-burned'' when probed by a second wave, even though the broadening mechanisms are conventionally homogeneous. This effect would be expected to work against the tendency of dye-switched ruby lasers to operate in a single mode. Related effects should play a role in optical pulse generators and in other devices using saturable absorbers.
A theory is presented for the effect of cross relaxation (CR) on the saturation with driving-signal intensity of the steady-state gain of a laser amplifier with an inhomogeneously broadened linewidth. The condition of steady-state gain results when the amplifier excitation level W and the driving-signal intensity are constant for about 3τ or longer, where τ is the fluorescence lifetime of the upper laser level. The driving signal is derived from an oscillator operated in the normal mode and which does not saturate the amplifier inversion density over times short compared with τ. We assume that CR, at a rate F, restores to thermal equilibrium any distortion of the spectral inversion density caused by the driving signal. Formulas are derived for steady-state gain saturation with arbitrary F for two cases: the spectral width of the driving signal is (1) narrow and (2) broad relative to the ionic or homogeneous line. The ionic linewidth Δvi is assumed to be much less than the inhomogeneous linewidth Δva and refers to the minimum frequency interval for which infinitely fast CR is operative. The theory also yields the CR coefficients f=(Δvi/Δva) [F/(τ−1+W)] for the narrow-band case and f*=(Δvs/Δva) [F/(τ−1+W)] for the broadband case, where Δvs is the driving-signal bandwidth. These coefficients significantly parametrize the CR effect: for f, f*>1, hole-burning is not severe, whereas for f, f*<1, considerable hole-burning takes place and the gain saturates faster. Finally, the theory is applied to experimental results obtained for Nd3+:glass broadband and narrow-band amplification; an approximate lower bound of 4×105 sec−1 is determined for F.
The nonlinear absorption of intense laser light is used to obtain information about the times required for spectral cross relaxation (T3{T}_{3}T3​) and collisional dephasing (T2{T}_{2}T2​) in organic-dye solutions. The steady-state transmission experiment of Huff and DeShazer indicates that T2{T}_{2}T2​ is in the range 0.1-1 psec for cryptocyanine-methanol, while T3{T}_{3}T3​ is in the range 1-10 psec. For DDI-glycerin (1, 1\ensuremath{'}-diethyl-2, 2\ensuremath{'}-dicarbocyanine-iodide-glycerin), measurements of ultrashort-pulse transmission as a function of incident energy and optical polarization suggest a value ${T}_{2}=0.4\ifmmode\pm\else\textpm\fi{}0.2$ psec for that system. These results are based on a new set of rate equations for absorption by inhomogeneously broadened organic-dye solutions. The equations display the effects of spectral cross relaxation and are not limited to light intensities less than those at which coherent interaction effects become important. For the case of ultrashort incident pulses, the equations are extended to account for excited-state absorption, the dependence of absorption on optical polarization, and the existence of a multiplicity of interacting excited states.
Theory based on a configuration coordinate model is presented to clarify solute–solvent relaxation effect on the line shape of a time-resolved hole-burning spectrum. The time-resolved hole-burning spectrum is affected by both a hole created in a ground-state population and an excess excited-state population. The solute–solvent relaxation causes thermalization in both populations and then the shift and broadening of the spectrum is expected observable. The line shapes of three typical cases are mainly considered: (1) The excited state is assumed to have an infinitely long lifetime; (2) the excited state has a finite lifetime, the population being assumed to relax toward an electronic state other than the ground state, and (3) the population created in the excited state relaxes to the ground state, where a hole-filling effect is taken into account. Results obtained by numerical calculations show that a time evolution of the ground-state hole is clearly observed when the low-energy tail of the absorption band is excited under the condition that the population decay to the other electronic state is very fast. Further, it is predicted that the hole-filling effect causes a considerable deformation of the spectral shape when the solvent relaxation rate is comparable to the excited-state population decay rate.