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

Journal of Applied Physics

Saturation of intersubband absorption and optical rectification in asymmetric quantum wells

M. Zal użny

Published Oct 1, 1993• 73 citations
Publisher

Abstract

The problem of saturation of intersubband absorption and optical rectification in asymmetric quantum wells is discussed theoretically using the density matrix formalism. The effects of the electron-electron interaction are taken into account. It is shown that near the resonance the spectral shapes of the nonlinear optical absorption coefficient and the nonlinear optical rectification coefficient are very similar. In the absence of the electron-electron interaction the spectral responses are nearly Lorentzian. The electron-electron interaction plays an important role in heavy doped systems. In structures with large spatial separation of the ground and the excited states wave functions, the depolarization effect is small and the absorption spectrum is affected mainly by the electrostatic Coulomb interaction. This interaction shifts the absorption peak to higher energy by an amount depending on the intensity of the incident light and leads to the significant distortion (asymmetry) of the line.

DOI
10.1063/1.354339

Related papers

Calculation of Nonlinear Intersubband Optical Absorption in Asymmetric Quantum Wells

Peng Tan

In the past few years advance in nanofabrication techniques have made it possible to make well-like compound semiconductor structures of low nanometer size.In these structures,the state of the electron in the direction perpendicular to the length of the well is quantized with sufficiently large separation in energy levels and the motion of the electron parallel to the length is that of a quasi-free electron.One of the most remarkable properties of these one-dimensional electron system is that the optical transitions between the size-quantized subbands are feasible.The result shows there is a large optical nonlinearities in asymmetric quantum wells.The problem of optical saturation of intersubband absorption has recently attracted considerable attention.The problem is very important to the development of superlattice devices such as fast infrared detectors and(modulators) because one needs to know the range of input optical intensities for which linear operation is(possible.) The analytical expression of the linear and the third-order nonlinear optical intersubband absorption coefficients are obtained in Pschl-Teller wells using the density matrix formalism taking into account the(intrasubband) relaxation.Since there are two adjustable parameters κ and λ in Pschl-Teller wells,the shapes of the wells will change with the change of the parameters κ and λ,accordingly the linear and the third-order nonlinear optical absorption coefficients will change with the parameters κ and λ.It is shown that the optical absorption coefficient depends on the parameter,and the optical intensity strongly. The absorption saturation will occur with I increase.Numerical results are presented for a typical AlGaAs/GaAs Pschl-Teller well.

Chinese Journal of Luminescence•Jan 1, 2006•0 citations

Influence of the depolarization effect on the nonlinear intersubband absorption spectra of quantum wells

M. Zal użny

The effect of the depolarization field on the nonlinear intersubband absorption spectrum of a rectangular quantum well (described by the two-subband model) is discussed. Calculations are performed in the framework of the density-matrix formulation with use of the relaxation-time approximation. Obtained results show that the depolarization effect not only shifts the peak by an amount depending on the intensity of the incident light but also leads to a significant distortion (asymmetry) of the line shape.

Physical review. B, Condensed matter•Feb 15, 1993•74 citations

Effect of Coulomb interaction on nonlinear (intensity-dependent) optical processes and intrinsic bistability in a quantum well under the electric and magnetic fields

İbrahim Karabulut

The effect of the electrostatic Coulomb interaction on the line shape related to the intensity-dependent intersubband optical processes in a Si δ-doped quantum well is studied using the density matrix formalism. The electronic structure of the quantum well is calculated from the self-consistent numerical solution of the coupled Schrödinger–Poisson equations. The line shape function is considerably modified by the optical intensity and the electric and magnetic fields. Moreover, we demonstrate the existence of the optical bistability for appropriate values of the optical intensity and also the control of the optical bistability with the electric and magnetic fields. It is also found that the intersubband relaxation time plays an important role in determining the optical bistability region.

Journal of Applied Physics•Mar 1, 2011•17 citations

On the doubly resonant difference frequency mixing in an asymmetric quantum well structure

M. Zal użny

The effect of the depolarization field on the doubly resonant frequency mixing due to resonant intersubband transitions in asymmetric quantum wells, with only the ground subband occupied, is discussed. Calculations are performed in the framework of the perturbative density matrix formulation with relaxation time approximation. The results show that in the considered system the depolarization effect can be included by simple replacement (in the one-electron expression for the nonlinear susceptibility) of the intersubband energy by the depolarization shifted intersubband energy.

Journal of Applied Physics•Aug 15, 1995•4 citations

Yarıiletken heteroyapıların lineer olmayan optik özellikleri.

Yıldırım, Hasan

The nonlinear optical properties of semiconductor heterostructures, such as GaAsAl/GaAs alloys, are studied with analytic and numerical methods on the basis of quantum mechanics. Particularly, second and third-order nonlinear optical properties of quantum wells described by the various types of confining potentials are considered within the density matrix formalism. We consider a Pöschl-Teller type potential which has been rarely considered in this area. It has a tunable asymmetry parameter, making it a good candidate to investigate the effect of the asymmetry on the nonlinear optical properties. The calculated nonlinear quantities include nonlinear absorption coefficient, second-harmonic generation, optical rectification, third-harmonic generation and the intensity-dependent refractive index. The effects of the DC electric field on the corresponding nonlinearities are also studied. The results are in good agreement with the results obtained in other types of quantum wells, such as square and parabolic quantum wells. The effects of the Coulomb interaction among the electrons on the nonlinear intersubband absorption are considered within the rotating wave approximation. The result is applied to a Si-delta-doped, square quantum well in which the Coulomb interaction among the electrons are relatively important, since there has been no work on the nonlinear absorption spectrum of the Si-\delta-doped quantum well. The results are found to be new and interesting, especially when a DC electric field is included in the calculations.

•Jan 1, 2006•0 citations

Calculation of Linear and Nonlinear Intersubband Optical Absorption in Electric-field Biased Hyperbolic Quantum Wells

Libing Chen

The analytic forms of the linear and the third-order nonlinear optical intersubband absorption coefficients were obtained for general asymmetric quantum well systems using the density matrix formalism.Based on the model,the linear and the third-order nonlinear intersubband optical absorptions in electric-field biased hyperbolic quantum wells were studied.The numerical results were presented for a typical AlxGa1-xAs/GaAs electric-field biased hyperbolic quantum wells.The results show that the contributors to the nonlinear absorption coefficient are due to the electric field,the shape of quantum well and the optical intensity.

ACTA PHOTONICA SINICA•Jan 1, 2009•0 citations
The problem of saturation of intersubband absorption and optical rectification in asymmetric quantum wells is discussed theoretically using the density matrix formalism. The effects of the electron-electron interaction are taken into account. It is shown that near the resonance the spectral shapes of the nonlinear optical absorption coefficient and the nonlinear optical rectification coefficient are very similar. In the absence of the electron-electron interaction the spectral responses are nearly Lorentzian. The electron-electron interaction plays an important role in heavy doped systems. In structures with large spatial separation of the ground and the excited states wave functions, the depolarization effect is small and the absorption spectrum is affected mainly by the electrostatic Coulomb interaction. This interaction shifts the absorption peak to higher energy by an amount depending on the intensity of the incident light and leads to the significant distortion (asymmetry) of the line.
In the past few years advance in nanofabrication techniques have made it possible to make well-like compound semiconductor structures of low nanometer size.In these structures,the state of the electron in the direction perpendicular to the length of the well is quantized with sufficiently large separation in energy levels and the motion of the electron parallel to the length is that of a quasi-free electron.One of the most remarkable properties of these one-dimensional electron system is that the optical transitions between the size-quantized subbands are feasible.The result shows there is a large optical nonlinearities in asymmetric quantum wells.The problem of optical saturation of intersubband absorption has recently attracted considerable attention.The problem is very important to the development of superlattice devices such as fast infrared detectors and(modulators) because one needs to know the range of input optical intensities for which linear operation is(possible.) The analytical expression of the linear and the third-order nonlinear optical intersubband absorption coefficients are obtained in Pschl-Teller wells using the density matrix formalism taking into account the(intrasubband) relaxation.Since there are two adjustable parameters κ and λ in Pschl-Teller wells,the shapes of the wells will change with the change of the parameters κ and λ,accordingly the linear and the third-order nonlinear optical absorption coefficients will change with the parameters κ and λ.It is shown that the optical absorption coefficient depends on the parameter,and the optical intensity strongly. The absorption saturation will occur with I increase.Numerical results are presented for a typical AlGaAs/GaAs Pschl-Teller well.
The effect of the depolarization field on the nonlinear intersubband absorption spectrum of a rectangular quantum well (described by the two-subband model) is discussed. Calculations are performed in the framework of the density-matrix formulation with use of the relaxation-time approximation. Obtained results show that the depolarization effect not only shifts the peak by an amount depending on the intensity of the incident light but also leads to a significant distortion (asymmetry) of the line shape.
The effect of the electrostatic Coulomb interaction on the line shape related to the intensity-dependent intersubband optical processes in a Si δ-doped quantum well is studied using the density matrix formalism. The electronic structure of the quantum well is calculated from the self-consistent numerical solution of the coupled Schrödinger–Poisson equations. The line shape function is considerably modified by the optical intensity and the electric and magnetic fields. Moreover, we demonstrate the existence of the optical bistability for appropriate values of the optical intensity and also the control of the optical bistability with the electric and magnetic fields. It is also found that the intersubband relaxation time plays an important role in determining the optical bistability region.
The effect of the depolarization field on the doubly resonant frequency mixing due to resonant intersubband transitions in asymmetric quantum wells, with only the ground subband occupied, is discussed. Calculations are performed in the framework of the perturbative density matrix formulation with relaxation time approximation. The results show that in the considered system the depolarization effect can be included by simple replacement (in the one-electron expression for the nonlinear susceptibility) of the intersubband energy by the depolarization shifted intersubband energy.
The nonlinear optical properties of semiconductor heterostructures, such as GaAsAl/GaAs alloys, are studied with analytic and numerical methods on the basis of quantum mechanics. Particularly, second and third-order nonlinear optical properties of quantum wells described by the various types of confining potentials are considered within the density matrix formalism. We consider a Pöschl-Teller type potential which has been rarely considered in this area. It has a tunable asymmetry parameter, making it a good candidate to investigate the effect of the asymmetry on the nonlinear optical properties. The calculated nonlinear quantities include nonlinear absorption coefficient, second-harmonic generation, optical rectification, third-harmonic generation and the intensity-dependent refractive index. The effects of the DC electric field on the corresponding nonlinearities are also studied. The results are in good agreement with the results obtained in other types of quantum wells, such as square and parabolic quantum wells. The effects of the Coulomb interaction among the electrons on the nonlinear intersubband absorption are considered within the rotating wave approximation. The result is applied to a Si-delta-doped, square quantum well in which the Coulomb interaction among the electrons are relatively important, since there has been no work on the nonlinear absorption spectrum of the Si-\delta-doped quantum well. The results are found to be new and interesting, especially when a DC electric field is included in the calculations.
The analytic forms of the linear and the third-order nonlinear optical intersubband absorption coefficients were obtained for general asymmetric quantum well systems using the density matrix formalism.Based on the model,the linear and the third-order nonlinear intersubband optical absorptions in electric-field biased hyperbolic quantum wells were studied.The numerical results were presented for a typical AlxGa1-xAs/GaAs electric-field biased hyperbolic quantum wells.The results show that the contributors to the nonlinear absorption coefficient are due to the electric field,the shape of quantum well and the optical intensity.