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

IEEE Journal of Quantum Electronics

9C6 - Experimental studies of saturable optical absorption

François Gires

Published Sep 1, 1966• 45 citations
Publisher

Abstract

The optical absorption of several substances has been found to depend in a reversible way on the incident light flux [1]-[5] of a high intensity laser. Moreover, it has been observed [6]-[7] that the absorption decreases not only at the laser wavelength but simultaneously within a large band around this wavelength. These effects may be explained by a time-dependant population distribution among the different excited states of absorbing molecules during the strong laser excitation [8]. The following experimental results enable us to determine the different time constants of importance in this phenomenon.

DOI
10.1109/jqe.1966.1074103

Related papers

Analytical approach to dynamics of reverse saturable absorbers

Andrey E. Kobyakov, David J. Hagan, Eric W. Van Stryland

We develop an analytical approach to the dynamics of band populations of reverse saturable absorbers modeled by the three-level approximation of the five-level rate equations. We find high-accuracy approximate solutions to these rate equations, taking into account the temporal shape of the incident laser pulse for different regimes of excitation. The results obtained are confirmed by direct numerical integration of the rate equations and are verified by solution of the full system of the rate and the propagation equations. The validity ranges of the approximations are determined. We also prove that for input pulses that are much longer than the lifetime of the first excited state the ground-state depletion obeys the same functional dependence on the input fluence as in the case of rectangular input pulses. The dynamics of the excited states, however, explicitly depends on the pulse shape. We quantitatively estimate the effect of various parameters on the nonlinear absorption coefficient and discuss implementation of the approach by a beam propagation method to reduce the computational time.

Journal of the Optical Society of America B•Nov 1, 2000•36 citations

Determination of nonlinear absorption mechanisms using a single pulse width laser

Feng Li, Yinglin Song, Kun Yang +6 more

A simple optical setup that uses a single pulse width laser is proposed to identify different kinds of nonlinear optical absorption mechanisms. It can easily distinguish reverse saturable absorption from two photon absorption, and direct three photon absorption from two photon absorption followed by one photon absorption from the excited level. Both theoretical and experimental results are reported.

Journal of Applied Physics•Sep 1, 1997•10 citations

Excited-state absorption and pump propagation effects on optical phase conjugation in a saturable absorber

Shigeki Miyanaga, Hiroaki Ohtateme, Katsunori Kawano +1 more

Phase conjugation by degenerate four-wave mixing in a saturable absorbing medium with a relatively long-lived excited state is analyzed; the analytical results are compared with experimental results. We propose a four-level model and take into account the effects of both excited-state absorption and pump propagation to explain the experimental results, which could not be explained by the models proposed previously. The numerical result predicts that the value of the phase-conjugate reflectivity as a function of the pump intensity is maximum at a certain absorbance (as absorbance increases) that is dependent on the cross section of the excited-state absorption. The present analysis explains most observations in the experiment, which was performed with a saturable-dye-doped polymer film as the saturable absorbing medium.

Journal of the Optical Society of America B•Jun 1, 1993•22 citations

Étude de l'absorption saturable

François Gires

Lorsqu'on irradie une transition optique avec sa lumière de résonance, on modifie le rapport des populations entre les deux niveaux, ce qui perturbe le spectre d'absorption de la substance irradiée. Lorsque l'éclairement est assez intense, l'absorption à la fréquence de résonance va jusqu'à disparaître, tandis que de nouvelles absorptions ou amplifications se manifestent. L'auteur indique les méthodes expérimentales permettant d'étudier ces phénomènes et passe en revue quelques-unes des applications de ces effets.

Journal de physique•Jan 1, 1969•8 citations

All-Optical Inverter using Negative Nonlinear Absorption Effect

Yoshinobu Maeda, Seiichi Ikeda, Masatoshi Migitaka

There has been considerable interest in all-optical devices for achieving the high-speed and parallel processing. Up to the present the amount of absorption in any absorption process has been considered to be proportional to the incident light intensity until in some cases saturation occurs [1]. Recently we observed experimentally negative nonlinear absorption (NNA) phenomena which cause transmission to decrease as the laser intensity increase and confirmed that the transmitted laser intensity with the variation of incident laser showed negative nonlinear (i. e. Maeda's effect) [2, 3]. In this report we demonstrate that the net quantity of light absorbed in an erbium doped yttrium aluminum garnet crystal can be a negative function of the incident laser intensity. The absorbing material has a four-level energy structure: absorption can occur between a ground level and an excited level and between two other excited levels. The input-output characteristic has a negative region due to the absorption between excited states.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jan 1, 1996•0 citations

Transient Bistability in a Laser Containing a Saturable Absorber

E. Arimondo, C. Gabbanini, E. Menchi +2 more

The question of the behaviour of the LSA when a control parameter is a slowly varying function of time, has recently been raised [1]. The investigation of the transient behaviour of a LSA is interesting not only in connection with the problem of the response time of optically bistable systems but also because in any real experiment, if one wants to explore a phase diagram, the parameters have to be changed in time. Although the relaxation times of the molecular medium and the cavity response time are of the order of 100μs or smaller, the time constants characterising the transient regime of the LSA may be much longer because of the critical slowing down which appears near the limit points of the hysteresis cycle[2]

International Meeting on Instabilities and Dynamics of Lasers and Nonlinear Optical Systems•Jan 1, 1985•0 citations
The optical absorption of several substances has been found to depend in a reversible way on the incident light flux [1]-[5] of a high intensity laser. Moreover, it has been observed [6]-[7] that the absorption decreases not only at the laser wavelength but simultaneously within a large band around this wavelength. These effects may be explained by a time-dependant population distribution among the different excited states of absorbing molecules during the strong laser excitation [8]. The following experimental results enable us to determine the different time constants of importance in this phenomenon.
We develop an analytical approach to the dynamics of band populations of reverse saturable absorbers modeled by the three-level approximation of the five-level rate equations. We find high-accuracy approximate solutions to these rate equations, taking into account the temporal shape of the incident laser pulse for different regimes of excitation. The results obtained are confirmed by direct numerical integration of the rate equations and are verified by solution of the full system of the rate and the propagation equations. The validity ranges of the approximations are determined. We also prove that for input pulses that are much longer than the lifetime of the first excited state the ground-state depletion obeys the same functional dependence on the input fluence as in the case of rectangular input pulses. The dynamics of the excited states, however, explicitly depends on the pulse shape. We quantitatively estimate the effect of various parameters on the nonlinear absorption coefficient and discuss implementation of the approach by a beam propagation method to reduce the computational time.
Phase conjugation by degenerate four-wave mixing in a saturable absorbing medium with a relatively long-lived excited state is analyzed; the analytical results are compared with experimental results. We propose a four-level model and take into account the effects of both excited-state absorption and pump propagation to explain the experimental results, which could not be explained by the models proposed previously. The numerical result predicts that the value of the phase-conjugate reflectivity as a function of the pump intensity is maximum at a certain absorbance (as absorbance increases) that is dependent on the cross section of the excited-state absorption. The present analysis explains most observations in the experiment, which was performed with a saturable-dye-doped polymer film as the saturable absorbing medium.
Lorsqu'on irradie une transition optique avec sa lumière de résonance, on modifie le rapport des populations entre les deux niveaux, ce qui perturbe le spectre d'absorption de la substance irradiée. Lorsque l'éclairement est assez intense, l'absorption à la fréquence de résonance va jusqu'à disparaître, tandis que de nouvelles absorptions ou amplifications se manifestent. L'auteur indique les méthodes expérimentales permettant d'étudier ces phénomènes et passe en revue quelques-unes des applications de ces effets.
There has been considerable interest in all-optical devices for achieving the high-speed and parallel processing. Up to the present the amount of absorption in any absorption process has been considered to be proportional to the incident light intensity until in some cases saturation occurs [1]. Recently we observed experimentally negative nonlinear absorption (NNA) phenomena which cause transmission to decrease as the laser intensity increase and confirmed that the transmitted laser intensity with the variation of incident laser showed negative nonlinear (i. e. Maeda's effect) [2, 3]. In this report we demonstrate that the net quantity of light absorbed in an erbium doped yttrium aluminum garnet crystal can be a negative function of the incident laser intensity. The absorbing material has a four-level energy structure: absorption can occur between a ground level and an excited level and between two other excited levels. The input-output characteristic has a negative region due to the absorption between excited states.
The question of the behaviour of the LSA when a control parameter is a slowly varying function of time, has recently been raised [1]. The investigation of the transient behaviour of a LSA is interesting not only in connection with the problem of the response time of optically bistable systems but also because in any real experiment, if one wants to explore a phase diagram, the parameters have to be changed in time. Although the relaxation times of the molecular medium and the cavity response time are of the order of 100μs or smaller, the time constants characterising the transient regime of the LSA may be much longer because of the critical slowing down which appears near the limit points of the hysteresis cycle[2]