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

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Optical multistability of exciton states in semiconductors

Bohdan M. Nitsovich, Claudia Yu. Zenkova

Published Nov 10, 1995• 0 citations
Publisher

Abstract

The nonlinear light transmission of semiconductors, in which the indirect exciton phototransition is realized, is studied. It is shown that the presence of two channels of dissipation of light wave energy of the indirect phototransition (the excitation of libration phonons) and exciton relaxation (the excitation of lattice phonons) -- leads to arising of optical multistable states in crystals. Investigations of polarization peculiarities of the dynamics of nonlinear processes with changing intensity of the input signal have been carried out.

DOI
10.1117/12.226731

Related papers

Exciton–Phonon Mechanism of Optical Bistability

Bohdan M. Nitsovich, O. V. Krechivskii, G. M. Pestryakov

Abstract A joint effect of exciton–phonon and exciton–exciton interactions on optical properties of semiconductors is studied. In these substances the exciton density is shown to be a multivalued function of incident light intensity and the frequency and temperature conditions under which the optical bistability arises are specified. Investigation of nonlinear optical properties of semiconductors with account for the indirect phototransitions exhibits that both multistable optical states and the bistable ones distinguished by a complicated dynamics of the switching may be observed in such systems.

physica status solidi (b)•Dec 1, 1988•2 citations

The peculiarities of optical bistability realization in the exciton absorption region of layer semiconductors

Oleksandr V. Derevyanchuk, Claudia Yu. Zenkova, Valeriy M. Kramar +1 more

The influence of the exciton and phonon spectra of layer semiconductors on the conditions of optical bistability (OB) realization in the exciton absorption region is investigated by means of the Green function method. Using the 2H-polytype PbI2 as an example, it has been found that an effective exciton scattering by an oscillation of the bending wave (BW) type leads to the short wave shift of the OB realization region, the decrease of its size, the widening of the OB observing temperature region and to the shift of the hysteresis loop in the direction of greater intensities, the decrease of its height and width. The possibility of observing the polarizable OB, connected with the direction of spreading and the insident light polarization dependence ofthe layer crystal exciton spectra is substantiated in this paper.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 19, 2006•1 citation

Optical bistability of a layered semiconductor in the exciton absorption region

K. Yu. Zenkova, Valeriy M. Kramar, N. K. Kramar +1 more

The effect of specific features of the exciton and phonon spectra of layered semiconductors on the conditions of realization of optical bistability in the exciton absorption region has been theoretically investigated by the Green’s function method. By the example of the 2 H polytype of PbI 2 , it is shown that effective exciton scattering from low-energy bending-wave vibrations leads to a blue shift of the frequency range of bistability realization and its narrowing; expansion of the temperature range of bistability observation; and a shift of the hysteresis loop to higher intensities, accompanied by a decrease in its height and width. The possibility of observing polarization optical bistability, which is related to the dependence of the exciton energy spectrum on the propagation direction of a light wave in a crystal, is also substantiated.

Optics and Spectroscopy•Nov 1, 2006•6 citations

Theory of optical bistability in the region of exciton resonances

Bohdan M. Nitsovich, C. Y. Zenkova

An exciton-phonon mechanism for producing cavityless optical bistability is suggested. We consider the influence of the oscillating subsystem of a crystal on the absorption process of a laser wave in the region of exciton frequencies. It is shown that exciton-phonon interaction leads to nonlinear dependence of the absorption coefficient on the density of the exciton gas. The increase of absorption with increasing exciton density, however, is possible only in the frequency region on the long-wavelength tail of the exiton band. As a result, the exciton density of the crystal becomes a hysteresis function of external parameters (intensity of the incident wave, temperature, etc.). We calculate the absorption coefficient of excitons and define the frequency and temperature regions where optical bistability may exist. We analyze different relaxation mechanisms of excitons and explain the experimental results of observing optical bistability in different semiconductor crystals.

Optical Engineering•Apr 1, 1995•11 citations

Excitonic molecules in semiconductors

V. D. Kulakovskiĭ, Valery G. Lysenko, Vladislav B. Timofeev

Great progress has been made in recent years in experimental studies of excitonic molecules, both in direct-band and indirect-band semiconductors. The exciton systems in these semiconductors differ substantially. In direct-band semiconductors with dipole-allowed optical transitions, the direct-recombination times are extremely small. Consequently the processes of binding of excitons into excitonic molecules and their decay occur under strongly nonequilibrium conditions. Hence one can obtain the fundamental information on biexcitons in these semiconductors by nonlinear optical methods. This review discusses the processes on which the various methods are based: two-photon resonance excitation of biexcitons, induced one-photon conversion of an exciton into a biexciton, two-photon resonance Raman scattering involving biexciton states, etc., and their application to studying biexcitons with the example of CdS. Problems of bistability involving biexcitons are also briefly discussed. In indirect semiconductors, where recombination occurs with the emission of a phonon, the lifetimes of excitons are large, and quasiequilibrium can be established in the exciton system. Under these conditions the information on the properties of the molecules is obtained by analyzing their radiative-decay spectra. The problem of detecting biexcitons in indirect semiconductors, radiative decay of molecules, and the effect on their stability of external electric, strain, and magnetic fields are discussed in detail with the examples of Si and Ge. Also the results of investigating the quantum statistical behavior of a dense gas of spin-oriented excitons (in a magnetic field under conditions in which the biexcitons are destabilized) are briefly presented (using the example of uniaxially compressed germanium), and the question of the possibility of their Bose condensation is discussed.

Soviet Physics Uspekhi•Sep 30, 1985•34 citations

Role of nonlinear exciton interactions in obtaining optical bistability

Bohdan M. Nitsovich, Claudia Yu. Zenkova, S. G. Kharinovich

This paper proposes for consideration an additional mechanism for influencing the exciton absorption spectra and observing temperature redistribution peculiarities of the crystal absorptive power. They are caused by nonlinear phonon-exciton interactions, which are due to anharmonic effects in the exciton-phonon system. The arising of the borderline frequency, which possesses the smallest region of optical bistability realization, is caused by a break in the direction of the absorption curve. At low temperatures the basic role is played by the exciton-exciton interaction, and at high temperatures nonlinear exciton-exciton-phonon processes play the most important role the value of the borderline frequency is defined by the size and sign of the nonlinear exciton-exciton-phonon function as well as by the crystal temperature and the exciton density, which is created by the external powerful laser wave.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Dec 1, 1997•1 citation
The nonlinear light transmission of semiconductors, in which the indirect exciton phototransition is realized, is studied. It is shown that the presence of two channels of dissipation of light wave energy of the indirect phototransition (the excitation of libration phonons) and exciton relaxation (the excitation of lattice phonons) -- leads to arising of optical multistable states in crystals. Investigations of polarization peculiarities of the dynamics of nonlinear processes with changing intensity of the input signal have been carried out.
Abstract A joint effect of exciton–phonon and exciton–exciton interactions on optical properties of semiconductors is studied. In these substances the exciton density is shown to be a multivalued function of incident light intensity and the frequency and temperature conditions under which the optical bistability arises are specified. Investigation of nonlinear optical properties of semiconductors with account for the indirect phototransitions exhibits that both multistable optical states and the bistable ones distinguished by a complicated dynamics of the switching may be observed in such systems.
The influence of the exciton and phonon spectra of layer semiconductors on the conditions of optical bistability (OB) realization in the exciton absorption region is investigated by means of the Green function method. Using the 2H-polytype PbI2 as an example, it has been found that an effective exciton scattering by an oscillation of the bending wave (BW) type leads to the short wave shift of the OB realization region, the decrease of its size, the widening of the OB observing temperature region and to the shift of the hysteresis loop in the direction of greater intensities, the decrease of its height and width. The possibility of observing the polarizable OB, connected with the direction of spreading and the insident light polarization dependence ofthe layer crystal exciton spectra is substantiated in this paper.
The effect of specific features of the exciton and phonon spectra of layered semiconductors on the conditions of realization of optical bistability in the exciton absorption region has been theoretically investigated by the Green’s function method. By the example of the 2 H polytype of PbI 2 , it is shown that effective exciton scattering from low-energy bending-wave vibrations leads to a blue shift of the frequency range of bistability realization and its narrowing; expansion of the temperature range of bistability observation; and a shift of the hysteresis loop to higher intensities, accompanied by a decrease in its height and width. The possibility of observing polarization optical bistability, which is related to the dependence of the exciton energy spectrum on the propagation direction of a light wave in a crystal, is also substantiated.
An exciton-phonon mechanism for producing cavityless optical bistability is suggested. We consider the influence of the oscillating subsystem of a crystal on the absorption process of a laser wave in the region of exciton frequencies. It is shown that exciton-phonon interaction leads to nonlinear dependence of the absorption coefficient on the density of the exciton gas. The increase of absorption with increasing exciton density, however, is possible only in the frequency region on the long-wavelength tail of the exiton band. As a result, the exciton density of the crystal becomes a hysteresis function of external parameters (intensity of the incident wave, temperature, etc.). We calculate the absorption coefficient of excitons and define the frequency and temperature regions where optical bistability may exist. We analyze different relaxation mechanisms of excitons and explain the experimental results of observing optical bistability in different semiconductor crystals.
Great progress has been made in recent years in experimental studies of excitonic molecules, both in direct-band and indirect-band semiconductors. The exciton systems in these semiconductors differ substantially. In direct-band semiconductors with dipole-allowed optical transitions, the direct-recombination times are extremely small. Consequently the processes of binding of excitons into excitonic molecules and their decay occur under strongly nonequilibrium conditions. Hence one can obtain the fundamental information on biexcitons in these semiconductors by nonlinear optical methods. This review discusses the processes on which the various methods are based: two-photon resonance excitation of biexcitons, induced one-photon conversion of an exciton into a biexciton, two-photon resonance Raman scattering involving biexciton states, etc., and their application to studying biexcitons with the example of CdS. Problems of bistability involving biexcitons are also briefly discussed. In indirect semiconductors, where recombination occurs with the emission of a phonon, the lifetimes of excitons are large, and quasiequilibrium can be established in the exciton system. Under these conditions the information on the properties of the molecules is obtained by analyzing their radiative-decay spectra. The problem of detecting biexcitons in indirect semiconductors, radiative decay of molecules, and the effect on their stability of external electric, strain, and magnetic fields are discussed in detail with the examples of Si and Ge. Also the results of investigating the quantum statistical behavior of a dense gas of spin-oriented excitons (in a magnetic field under conditions in which the biexcitons are destabilized) are briefly presented (using the example of uniaxially compressed germanium), and the question of the possibility of their Bose condensation is discussed.
This paper proposes for consideration an additional mechanism for influencing the exciton absorption spectra and observing temperature redistribution peculiarities of the crystal absorptive power. They are caused by nonlinear phonon-exciton interactions, which are due to anharmonic effects in the exciton-phonon system. The arising of the borderline frequency, which possesses the smallest region of optical bistability realization, is caused by a break in the direction of the absorption curve. At low temperatures the basic role is played by the exciton-exciton interaction, and at high temperatures nonlinear exciton-exciton-phonon processes play the most important role the value of the borderline frequency is defined by the size and sign of the nonlinear exciton-exciton-phonon function as well as by the crystal temperature and the exciton density, which is created by the external powerful laser wave.