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

Optics Letters

Two-photon absorption and third-order nonlinearities in GaAs quantum dots

L. Bányai, Markus Lindberg, Stefan W. Koch

Published Mar 1, 1988• 38 citations
Publisher

Abstract

Third-order optical nonlinearities of GaAs quantum dots are investigated theoretically. Two quantum confinement regimes are analyzed, and large optical nonlinearities are predicted for sufficiently narrow linewidths. The appearance of an induced (two-photon) absorption resonance is predicted energetically above the exciton resonance for quantum-dot radii, which are between the electron and hole Bohr radii.

DOI
10.1364/ol.13.000212

Related papers

Third-order Nonlinear Optical Susceptibility in Quantum Disks

Cui Liu

In recent years,the subject of optical nonlinearity in semiconductor quantum confined structures such as quantum wires and quantum dots has attracted a considerable attention because of their relevance for studying practical applications and as a probe for the electronic structure of media.It has been shown that the low dimensional quantum systems present very large nonlinear optical susceptibilities .Theoretically,most of the studies on quantum dots are focused on spherical quantum dots for simplicity.The shape of quantum dot depends on growth conditions.In fact,quantum dots are better described as thin disk or cylinder.In the present work third order nonlinear optical susceptibilities in disk shaped quantum dots due to resonant intersubband transition are analyzed by a compact density matrix approach.It has rarely been discussed in literatures.Firstly,we consider an electron moving in a quantum disk whose radius R is very large compared to its thickness d .For simplicity,we assume that the isotropic effective mass approximation is valid within the disk and that the inner potential is null while the outer confining potential is approximately infinite.Using the adiabatic approximation we solve the three dimensional Schrdinger equation and obtain the analytical expressions of wave functions and energy levels in cylindrical coordinates.Secondly,we consider the system is excited by an electromagnetic field with frequency ω. The electromagnetic field is incident with a polarization vector normal to the disk.We treat H′=ezE(t) as a perturbation term.By using the compact density matrix method,we derive a general formula for third order nonlinear optical susceptibilites employing a four level model in quantum disk.Finally,numerical results are illustrated for a typical GaAs quantum disk.We calculate the third order nonlinear optical susceptibilities as a function of the disk thickness.It is shown that the third order nonlinear optical susceptibilities in quantum disk are 10～100 times larger than that in quantum well for various disk thickness.Furthermore,if we choose an optimized thickness of quantum disk,we could obtain a quite large refractive index with a comparatively small absorption coefficient.Therefore,we suggest that the quantum dots would be an excellent system in the field of optical communications and optical switching.

Chinese Journal of Luminescence•Jan 1, 2001•1 citation

Linear and nonlinear optical absorptions in one-dimensional quantum dot with semi-parabolic confining potential

Youbin Yu

Linear and nonlinear optical absorptions in one-dimensional semi-parabolic quantum dot is investigated. The analytical expression of linear and third-order nonlinear optical absorption coefficients are obtained by using compact density-matrix approach and iterative method. Numerical results are presented for an GaAs/AlGaAs quantum dot and the dependence on the quantum confinement of the semi-parabolic quantum dot, the incident optical intensity, and on the relaxation rate are also investigated. The results indicate that the optical absorption coefficients are strongly influenced by the confining frequency, relaxation time, and the incident optical intensity, respectively. However, their influences for the linear optical absorption, third-order nonlinear optical absorption, and the total optical absorption are different. We think our theoretical study may make a great contribution to experimental studies and may open up new opportunities for practical exploitation of the quantum-size effect in optical devices.

IEEE International Conference on Nanotechnology (IEEE-NANO)•Aug 1, 2013•0 citations

BIEXCITONIC EFFECT ON TRANSIENT NONLINEAR REFRACTION AND ABSORPTION IN A MAGNETIZED CdS QUANTUM DOTS

Swati Goyal, Pranay K. Sen

Transient optical nonlinearities of semiconductor quantum dots in the strongly confined regime are studied, in which the exciton, biexciton and magnetic field effects are taken into account. The photo induced band-to-band electronic transitions are considered from both the heavy-hole (hh) and light-hole (lh) valence bands to the lowest (1s) exciton state below the fundamental absorption edge. The time dependent perturbation technique for a three-level system, under the near band gap resonant excitation regime, has been employed; with the incorporation of the relaxation and dephasing mechanisms phenomenologically. The induced polarization is calculated from where the real and imaginary parts of the third-order nonlinear optical susceptibility, responsible for the occurrence of nonlinear refraction and nonlinear absorption respectively, have been derived. The temporal and detuning spectra of nonlinear refraction and absorption; and their dependence on density of biexcitons and a moderately strong magnetic field, have been analyzed. It is observed that the nonlinear refraction and nonlinear absorption enhance with increasing magnetic field in small CdS quantum dots.

International Journal of Nanoscience•Aug 1, 2011•1 citation

Optical absorption saturation of semiconductor quantum dots

David A. B. Miller, D. S. Chemla, Stefan Schmitt-Rink

We have analyzed theoretically the optical absorption saturation of semiconductor microcrystallites so small that they show strong quantum confinement in all three dimensions [quantum dots (QDs)]. We show that saturation of the lowest energy excited state becomes extremely simple to describe even including excitonic effects. Such QDs exhibit novel physical properties, including very large optical absorption per unit volume, that make QDs very attractive nonlinear media.

Journal of the Optical Society of America B•Jan 1, 1986•0 citations

Non-linear optical properties of excitonic complexes in prolate ellipsoidal quantum dot

Yuri Y. Bleyan, Maxim Ya. Vinnichenko, Nabil Zeiri +2 more

This study presents a theoretical study of ground-state exciton and biexciton properties in strongly prolate ellipsoidal GaAs quantum dot. Using a variational approach with trial wave functions constructed from single-particle states, we examine the dependence of exciton and biexciton energies on the dot’s geometric parameters. The oscillator strengths of exciton–biexciton transitions are analyzed as functions of the major and minor semiaxes. We further investigate the third-order optical susceptibility near single- and two-photon resonances, elucidating the role of exciton–biexciton interactions. The results show that one-photon resonances dominate the nonlinear response, with contributions exceeding those of two-photon resonances by approximately four orders of magnitude. Absorption coefficients for exciton and biexciton transitions are evaluated for a fixed major semiaxis and varying minor semiaxis, along with the biexciton two-photon absorption coefficient. Finally, we analyze biexciton-induced nonlinear refractive index modulation, which exhibits a sign reversal across resonance and a pronounced peak–dip structure, indicating strong dispersive behavior and significant excitonic phase modulation.

Results in Optics•Feb 1, 2026•1 citation

Hybrid optical properties of GaAs quantum dots

Teslim Alabi, IC Ndukwe, Chibueze Paul Onyenegecha +1 more

The study presents results of the linear and non-linear optical properties of GaAs quantum dots. The reported work aims to provide new results of the quantum dot optical properties confined in Hua plus modified Eckart (HPME) potential. To obtain analytical expressions for the energy eigenvalues and the wave functions, we solved the time-independent Schrödinger equation for the HPME potential by using the parametric Nikiforov-Uvarov (NU) method. Investigation of the linear, third-order nonlinear, and total absorption coefficients and refractive index changes was done with the help of the density matrix approach. The results showed that the energy decreases in a linear manner as the potential parameter, V0. Also, it is observed that as the barrier slope increases, the peaks of the linear, third-order linear, and total absorption coefficient tend to higher values of energy. Furthermore, as the barrier slope increases, the change in refractive indices increases, and their positions shift to higher energies. Additionally, an increase in the structure parameters and optical intensity greatly influences the absorption coefficients and the refractive index changes of the quantum dots.

Science World Journal•Jan 1, 2025•0 citations
Third-order optical nonlinearities of GaAs quantum dots are investigated theoretically. Two quantum confinement regimes are analyzed, and large optical nonlinearities are predicted for sufficiently narrow linewidths. The appearance of an induced (two-photon) absorption resonance is predicted energetically above the exciton resonance for quantum-dot radii, which are between the electron and hole Bohr radii.
In recent years,the subject of optical nonlinearity in semiconductor quantum confined structures such as quantum wires and quantum dots has attracted a considerable attention because of their relevance for studying practical applications and as a probe for the electronic structure of media.It has been shown that the low dimensional quantum systems present very large nonlinear optical susceptibilities .Theoretically,most of the studies on quantum dots are focused on spherical quantum dots for simplicity.The shape of quantum dot depends on growth conditions.In fact,quantum dots are better described as thin disk or cylinder.In the present work third order nonlinear optical susceptibilities in disk shaped quantum dots due to resonant intersubband transition are analyzed by a compact density matrix approach.It has rarely been discussed in literatures.Firstly,we consider an electron moving in a quantum disk whose radius R is very large compared to its thickness d .For simplicity,we assume that the isotropic effective mass approximation is valid within the disk and that the inner potential is null while the outer confining potential is approximately infinite.Using the adiabatic approximation we solve the three dimensional Schrdinger equation and obtain the analytical expressions of wave functions and energy levels in cylindrical coordinates.Secondly,we consider the system is excited by an electromagnetic field with frequency ω. The electromagnetic field is incident with a polarization vector normal to the disk.We treat H′=ezE(t) as a perturbation term.By using the compact density matrix method,we derive a general formula for third order nonlinear optical susceptibilites employing a four level model in quantum disk.Finally,numerical results are illustrated for a typical GaAs quantum disk.We calculate the third order nonlinear optical susceptibilities as a function of the disk thickness.It is shown that the third order nonlinear optical susceptibilities in quantum disk are 10～100 times larger than that in quantum well for various disk thickness.Furthermore,if we choose an optimized thickness of quantum disk,we could obtain a quite large refractive index with a comparatively small absorption coefficient.Therefore,we suggest that the quantum dots would be an excellent system in the field of optical communications and optical switching.
Linear and nonlinear optical absorptions in one-dimensional semi-parabolic quantum dot is investigated. The analytical expression of linear and third-order nonlinear optical absorption coefficients are obtained by using compact density-matrix approach and iterative method. Numerical results are presented for an GaAs/AlGaAs quantum dot and the dependence on the quantum confinement of the semi-parabolic quantum dot, the incident optical intensity, and on the relaxation rate are also investigated. The results indicate that the optical absorption coefficients are strongly influenced by the confining frequency, relaxation time, and the incident optical intensity, respectively. However, their influences for the linear optical absorption, third-order nonlinear optical absorption, and the total optical absorption are different. We think our theoretical study may make a great contribution to experimental studies and may open up new opportunities for practical exploitation of the quantum-size effect in optical devices.
Transient optical nonlinearities of semiconductor quantum dots in the strongly confined regime are studied, in which the exciton, biexciton and magnetic field effects are taken into account. The photo induced band-to-band electronic transitions are considered from both the heavy-hole (hh) and light-hole (lh) valence bands to the lowest (1s) exciton state below the fundamental absorption edge. The time dependent perturbation technique for a three-level system, under the near band gap resonant excitation regime, has been employed; with the incorporation of the relaxation and dephasing mechanisms phenomenologically. The induced polarization is calculated from where the real and imaginary parts of the third-order nonlinear optical susceptibility, responsible for the occurrence of nonlinear refraction and nonlinear absorption respectively, have been derived. The temporal and detuning spectra of nonlinear refraction and absorption; and their dependence on density of biexcitons and a moderately strong magnetic field, have been analyzed. It is observed that the nonlinear refraction and nonlinear absorption enhance with increasing magnetic field in small CdS quantum dots.
This study presents a theoretical study of ground-state exciton and biexciton properties in strongly prolate ellipsoidal GaAs quantum dot. Using a variational approach with trial wave functions constructed from single-particle states, we examine the dependence of exciton and biexciton energies on the dot’s geometric parameters. The oscillator strengths of exciton–biexciton transitions are analyzed as functions of the major and minor semiaxes. We further investigate the third-order optical susceptibility near single- and two-photon resonances, elucidating the role of exciton–biexciton interactions. The results show that one-photon resonances dominate the nonlinear response, with contributions exceeding those of two-photon resonances by approximately four orders of magnitude. Absorption coefficients for exciton and biexciton transitions are evaluated for a fixed major semiaxis and varying minor semiaxis, along with the biexciton two-photon absorption coefficient. Finally, we analyze biexciton-induced nonlinear refractive index modulation, which exhibits a sign reversal across resonance and a pronounced peak–dip structure, indicating strong dispersive behavior and significant excitonic phase modulation.
The study presents results of the linear and non-linear optical properties of GaAs quantum dots. The reported work aims to provide new results of the quantum dot optical properties confined in Hua plus modified Eckart (HPME) potential. To obtain analytical expressions for the energy eigenvalues and the wave functions, we solved the time-independent Schrödinger equation for the HPME potential by using the parametric Nikiforov-Uvarov (NU) method. Investigation of the linear, third-order nonlinear, and total absorption coefficients and refractive index changes was done with the help of the density matrix approach. The results showed that the energy decreases in a linear manner as the potential parameter, V0. Also, it is observed that as the barrier slope increases, the peaks of the linear, third-order linear, and total absorption coefficient tend to higher values of energy. Furthermore, as the barrier slope increases, the change in refractive indices increases, and their positions shift to higher energies. Additionally, an increase in the structure parameters and optical intensity greatly influences the absorption coefficients and the refractive index changes of the quantum dots.