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 Lasers and Electro-Optics Society Annual Meeting (LEOS)

Excitonic nonlinear optical responses

Eiichi Hanamura

Published Dec 30, 2002• 0 citations
Publisher

Abstract

The enhancement of /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/) and switching rate has been confirmed under resonant pumping of coherent excitons. We propose theoretically the following nonlinear optical responses of the exciton: (1) Superradiance of Frenkel excitons and excitonic n-strings; (2) Frenkel and Wannier excitons show different characteristics of the third-order optical responses /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/); (3) Generation of phase-conjugated wave shows singular spectrum near mobility edge of the exciton in a bulk crystal.>

DOI
10.1109/leos.1993.379107

Related papers

Optical nonlinearities due to excitonic molecules: Optical Stark effects and phase conjugation

Eiichi Hanamura

Large, nonlinear-optical phenomena are shown theoretically to be observable under nearly two-photon resonant pumping of the excitonic molecule (EM), e.g., in a CuCl crystal. When the exciton polariton (EP) is resonantly pumped into the EM, they are hybridized with each other and show optical Stark splitting. These splittings can be observed, respectively, as a sharp dip in the reflection spectrum and two-photon absorption spectrum due to the EM. We can also clarify how these splittings change into the blueshifts and redshifts of the EP and the EM as functions of the pump frequency and power. The generation of the phase-conjugated wave is shown also to be enhanced under two-photon resonant pumping of the EM. Some characteristics about pump-probe frequency and polarization dependences are also clarified. We have also derived the effective Hamiltonian of the exciton and the EM from the first-principles equation of motion for the exciton coupled with that of the EM. This Hamiltonian has made possible the theoretical analysis of these nonlinear-optical phenomena.

Physical review. B, Condensed matter•Oct 15, 1991•15 citations

Mechanisms of the low density nonlinear optical response of excitons in gallium arsenide and the study of exciton transport.

A. C. Schaefer

The study of the nonlinear optical response of excitons in semiconductors is important for both scientific and technological applications. Although the nonlinear optical properties of bulk semiconductors and heterostructures have been studied for almost three decades, with most of the research focusing on heterostructures, the mechanisms leading to the nonlinearities in these systems are not completely understood. Determining these mechanisms and developing a theoretical picture which describes the most dominant effects remains a challenge and an active area of study. Although optical interactions in semiconductors is a genuine many-body problem, a description of this system similar to the optical Bloch equations used in atomic studies has shown some success, but more work is needed to make this model complete. Experimental work, particularly in the bulk system uncomplicated by the interface disorder present in heterostructures, will provide the guidance to extend this formalism. In this dissertation, the frequency domain resonant nonlinear optical response of excitons in bulk gallium arsenide at low density is studied to gain insight into the dominant mechanisms leading to the response, as well as the dynamics of the nominally three-dimensional excitonic system. Specifically, the nonlinear response was probed with differential transmission (DT) and four-wave mixing (FWM) experiments, which measure to lowest order the third-order susceptibility, $\chi\sp{(3)}.$ Using these various tools, three specific areas were studied and the results will be presented. First, the role of the biexciton, the state of two bound excitons, in determining the bulk nonlinear response was explored. The observation of a red-shifted nonlinear resonance suggests the importance of this state at moderate densities. Second, a new response, characterized by a resonant increase in exciton absorption induced by optical pumping with initial superlinear growth and a transition to behavior described by simple line broadening with increased pump intensity, was studied in detail. A model considering increased polariton absorption with increased exciton-exciton interactions explains these effects. Finally, nonlinear optical spectroscopy was used to study exciton transport, where near-ballistic behavior was revealed. The effect of exciton transport, thermalization and radiative recombination on the nonlinear optical response was explored.

•Jan 1, 1996•0 citations

Excitonic correlations in nonlinear phase shift in semiconductor quantum wells

Ryu Takayama, N. H. Kwong, I. Rumyantsev +2 more

Summary form only given. The nonlinear optics near the fundamental absorption edge is commonly formulated in terms of a limited number of material parameters characterizing the strength of specific nonlinear processes. Once the nonlinear response function underlying these material parameters is known, one can optimize the relevant nonlinear optical effect for specific device applications. This study is focused on optical nonlinearities at quasi-resonant conditions in the picosecond-pulse regime, where excitonic correlations, such as biexcitonic resonances, contribute prominently to the physical processes. Using a microscopic theory, we have calculated systematically the parameter dependencies of some representative figures of merit, nonlinear phase shift /spl Delta//spl phi/ and differential transmissivity AT, which provide complementary information on the nonlinear susceptibility-/spl chi//sup (3)/:/spl Delta//spl phi//spl sim/Re/spl chi//sup (3)/, /spl Delta/T/spl sim/Im/spl chi//sup (3)/, approximately. We will show in detail how the various aspects of excitonic dynamics affect these quantities around the exciton resonance.

Quantum Electronics and Laser Science Conference•Nov 13, 2002•0 citations

Third-order optical response of intermediate excitons with fractional nonlinear statistics

Vladimir Chernyak, Shaul Mukamel

The interplay of exciton statistics and Coulomb interactions in the optical response of semiconductors is studied by derivation of an effective Hamiltonian written in terms of exciton operators, starting with a two-band model. Statistical effects are incorporated through the nonboson commutation relations of exciton operators, which contain an exciton-size-dependent parameter q that may vary from q = 0 (boson statistics) through q ≪ 1 (Wannier excitons) to q = 2 (Frenkel excitons or Pauli statistics). A unified Green’s function expression for χ(3) that applies to excitons of an arbitrary nature is derived.

Journal of the Optical Society of America B•Jun 1, 1996•48 citations

/spl chi//sup (5)/-signatures in the optical Stark effect

Peter Brick, Claudia Ell, G. Khitrova +3 more

Summary form only given. Recently a lot of interest has been focused on higher-order Coulomb correlations. It was shown, that even in the /spl chi//sup (3)/-limit higher-order excitonic correlations, i.e., bound and unbound two exciton states, influence the coherent optical response. While /spl chi//sup (3)/-contributions to the excitonic Stark effect are well understood, very little is known about the influence of /spl chi//sup (5)/-contributions. Here we investigate the dependence of coherent pump-induced excitonic absorption changes on the pump intensity and relate our results to fifth-order contributions. Pump-probe experiments are performed on high-quality InGaAs quantum wells dominated by a heavy-hole exciton resonance.

Quantum Electronics and Laser Science Conference•May 12, 2000•0 citations

Superradiative Decay and Enhanced Optical Nonlinearity of Excitons in Qunatum Wells

E. Hanamura

We evaluate the exciton coherence length and discuss theoretically how it determines its superradiative decay time and its third-order optical nonlinearity in the qunatum wells and microcrystallites.

Nonlinear Optical Properties of Materials•Jan 1, 1988•0 citations
The enhancement of /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/) and switching rate has been confirmed under resonant pumping of coherent excitons. We propose theoretically the following nonlinear optical responses of the exciton: (1) Superradiance of Frenkel excitons and excitonic n-strings; (2) Frenkel and Wannier excitons show different characteristics of the third-order optical responses /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/); (3) Generation of phase-conjugated wave shows singular spectrum near mobility edge of the exciton in a bulk crystal.>
Large, nonlinear-optical phenomena are shown theoretically to be observable under nearly two-photon resonant pumping of the excitonic molecule (EM), e.g., in a CuCl crystal. When the exciton polariton (EP) is resonantly pumped into the EM, they are hybridized with each other and show optical Stark splitting. These splittings can be observed, respectively, as a sharp dip in the reflection spectrum and two-photon absorption spectrum due to the EM. We can also clarify how these splittings change into the blueshifts and redshifts of the EP and the EM as functions of the pump frequency and power. The generation of the phase-conjugated wave is shown also to be enhanced under two-photon resonant pumping of the EM. Some characteristics about pump-probe frequency and polarization dependences are also clarified. We have also derived the effective Hamiltonian of the exciton and the EM from the first-principles equation of motion for the exciton coupled with that of the EM. This Hamiltonian has made possible the theoretical analysis of these nonlinear-optical phenomena.
The study of the nonlinear optical response of excitons in semiconductors is important for both scientific and technological applications. Although the nonlinear optical properties of bulk semiconductors and heterostructures have been studied for almost three decades, with most of the research focusing on heterostructures, the mechanisms leading to the nonlinearities in these systems are not completely understood. Determining these mechanisms and developing a theoretical picture which describes the most dominant effects remains a challenge and an active area of study. Although optical interactions in semiconductors is a genuine many-body problem, a description of this system similar to the optical Bloch equations used in atomic studies has shown some success, but more work is needed to make this model complete. Experimental work, particularly in the bulk system uncomplicated by the interface disorder present in heterostructures, will provide the guidance to extend this formalism. In this dissertation, the frequency domain resonant nonlinear optical response of excitons in bulk gallium arsenide at low density is studied to gain insight into the dominant mechanisms leading to the response, as well as the dynamics of the nominally three-dimensional excitonic system. Specifically, the nonlinear response was probed with differential transmission (DT) and four-wave mixing (FWM) experiments, which measure to lowest order the third-order susceptibility, $\chi\sp{(3)}.$ Using these various tools, three specific areas were studied and the results will be presented. First, the role of the biexciton, the state of two bound excitons, in determining the bulk nonlinear response was explored. The observation of a red-shifted nonlinear resonance suggests the importance of this state at moderate densities. Second, a new response, characterized by a resonant increase in exciton absorption induced by optical pumping with initial superlinear growth and a transition to behavior described by simple line broadening with increased pump intensity, was studied in detail. A model considering increased polariton absorption with increased exciton-exciton interactions explains these effects. Finally, nonlinear optical spectroscopy was used to study exciton transport, where near-ballistic behavior was revealed. The effect of exciton transport, thermalization and radiative recombination on the nonlinear optical response was explored.
Summary form only given. The nonlinear optics near the fundamental absorption edge is commonly formulated in terms of a limited number of material parameters characterizing the strength of specific nonlinear processes. Once the nonlinear response function underlying these material parameters is known, one can optimize the relevant nonlinear optical effect for specific device applications. This study is focused on optical nonlinearities at quasi-resonant conditions in the picosecond-pulse regime, where excitonic correlations, such as biexcitonic resonances, contribute prominently to the physical processes. Using a microscopic theory, we have calculated systematically the parameter dependencies of some representative figures of merit, nonlinear phase shift /spl Delta//spl phi/ and differential transmissivity AT, which provide complementary information on the nonlinear susceptibility-/spl chi//sup (3)/:/spl Delta//spl phi//spl sim/Re/spl chi//sup (3)/, /spl Delta/T/spl sim/Im/spl chi//sup (3)/, approximately. We will show in detail how the various aspects of excitonic dynamics affect these quantities around the exciton resonance.
The interplay of exciton statistics and Coulomb interactions in the optical response of semiconductors is studied by derivation of an effective Hamiltonian written in terms of exciton operators, starting with a two-band model. Statistical effects are incorporated through the nonboson commutation relations of exciton operators, which contain an exciton-size-dependent parameter q that may vary from q = 0 (boson statistics) through q ≪ 1 (Wannier excitons) to q = 2 (Frenkel excitons or Pauli statistics). A unified Green’s function expression for χ(3) that applies to excitons of an arbitrary nature is derived.
Summary form only given. Recently a lot of interest has been focused on higher-order Coulomb correlations. It was shown, that even in the /spl chi//sup (3)/-limit higher-order excitonic correlations, i.e., bound and unbound two exciton states, influence the coherent optical response. While /spl chi//sup (3)/-contributions to the excitonic Stark effect are well understood, very little is known about the influence of /spl chi//sup (5)/-contributions. Here we investigate the dependence of coherent pump-induced excitonic absorption changes on the pump intensity and relate our results to fifth-order contributions. Pump-probe experiments are performed on high-quality InGaAs quantum wells dominated by a heavy-hole exciton resonance.