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

Acta Physica Polonica A

The Nonlinear Absorption Coefficient for Direct Two-Photon Creation of Biexciton

W. Ungier, Maciej Suffczynski

Published Feb 1, 2002• 0 citations
Publisher

Abstract

The absorption coefficient for the two-photon creation of biexciton is calculated for CuCl and wurtzite crystals. Because of the resonance effect only the intermediate lowest optically active excitonic states are taken into account. The absorption coefficient is expressed by a functional of the biexciton envelope. The numerical results are computed with the envelope function of Hylleraas-Ore type (modified and minimized by Brinkman et al). The obtained results for CuCI are in good agreement with absorption measurements published by Gale and Mysyrowicz.

DOI
10.12693/aphyspola.101.295

Related papers

Direct Two-Photon Creation of Excitonic Molecule in CuCl

W. Ungier, P. Janiszewski, Maciej Suffczynski

The probability of direct excitation of excitonic molecule in the two-photon absorption process is calculated with an Hylleraas-Ore type biexciton envelope, which is variationally optimized.In the second order of perturbation, because of the resonance effect, only the exciton .r5intermediate state is taken into account.The band structure at band extrema due to spin-orbit interaction is assumed.The transition probability of two-photon absorption is expressed by matrix element between the free exciton and the biexciton envelopes.The obtained probability of two-photon absorption in CuCl is about three orders of magnitude smaller when compared to that obtained by Hauamura.

Acta Physica Polonica A•Oct 1, 2000•1 citation

Optical Nonlinearity and Bistability due to the Biexciton Two-Photon Resonance in CuCI

Nasser N. Peyghambarian, Dror Sarid, H. M. Gibbs

It is well established that biexcitons can be generated directly by two-photon absorption in CuCI. The intensity dependent nonlinearity arising from this resonance can be used to obtain optical bistability. Recently, Koch and Haug(1) and also Hanamura(2) have predicted the possibility of a bistable operation in a CuCI Fabry-Perot etalon. Hanamura uses a density matrix formalism and predicts that the switching can respond in a picosecond time scale due to the virtual formation of biexcitons. Koch and Haug obtain the complex dielectric function from a Green's function formalism and suggest a bistable behavior for a thin CuCI slab. They use a constant value for the biexciton linewidth, γxx, and a zero value for the exciton linewidth, γx. Their results indicate that a 1-μm-thick CuCI etalon, with natural reflecting surfaces, can give rise to bistability with a switch-on intensity of about 0.1 MW/cm2. The biexciton resonance, however, is located on the tail of the exciton resonance, which acts as a background absorption.

Topical Meeting on Optical Bistability (OB)•Jan 1, 1983•0 citations

Biexciton resonant two‐photon absorption in CuCl

Vu Duy Phach, Albert Bivas, B. Hönerlage +1 more

Abstract In studying the two‐photon absorption (TPA) of the biexciton in CuCl by using two different light sources, interesting information is obtained. The biexciton ground‐state energy is determined accurately; its symmetry is experimentally verified; a value for the TPA coefficient is deduced and compared with a theoretical evaluation; a lineshape analysis enables us to discuss the damping constants of the exciton and biexciton states involved.

physica status solidi (b)•Dec 1, 1977•81 citations

Lo‐phonon‐assisted two‐photon absorption of the first excited state of the biexciton in CuCl

Walter Ekardt, M. I. Sheboul

Abstract LO‐phonon‐assisted two‐photon absorption of the first excited level of the excitonic molecule in CuCl is considered on the basis of the previously derived symmetry properties of this state. A giant cross‐section for this process is predicted mainly due to the “resonant” intermediate state Γ 1/5 of the single exciton. The process under consideration overcomes the difficulties of pure two‐photon absorption (TPA) of p‐type envelope states of the excitonic molecule as stated by Hanamura.

physica status solidi (b)•Mar 1, 1977•5 citations

Stationary properties of dispersive optical bistability in a dense exciton-biexciton system: copper chloride

C. M. Bowden, Joseph W. Haus, Chi C. Sung +1 more

Abstract A semiclassical exciton-biexciton model for CuCl is used to obtain the stationary solutions for optical bistability (o.b.) by numerical integration of the second-order Maxwell equation in the limit of large Fresnel numbers. The results obtained from the calculation, which we call exact (ex.), are compared with corresponding numerical results by using the slowly varying envelope approximation (s.v.e.a.) as well as corresponding analytical results obtained by using the mean-field approximation (m.f.a.). The results obtained with the s.v.e.a. are shown to be in close quantitative (within 5%) agreement with the ex. results for each point in the parameter space considered, whereas the m.f.a. gives reasonably good qualitative results only (more than 20% quantitative discrepancy with ex.). Furthermore, o.b. is predicted from these calculations for incident laser field detunings on either side of the two-photon biexciton resonance as well as in the neighbourhood of the resonance. The nonlinearity in the dielectric function that causes o.b. is seen to be very nearly of the Kerr medium type, and consequently, the two-photon biexciton resonance contributes only weakly to the o.b. characteristics.

Philosophical Transactions of the Royal Society of London Series A Mathematical and Physical Sciences•Dec 18, 1984•0 citations

Phonon‐Assisted Two‐Photon Absorption of the Excitonic Molecule in CuCl I. Bare‐Exciton Approach

Walter Ekardt, H.-J. Brocksch

Abstract Phonon‐assisted two‐photon absorption of biexcitonic levels in CuCl is considered including damping of the nearly resonant excitonic intermediate state. A pronounced structure of the line shape due to resonance effects, threshold effects, and structure in the Fourier transform of the envelope of the excitonic molecule is predicted. A detailed discussion of both temperature and damping effects is given. Large cross sections are predicted. The most favourable energetic range to observe the effects derived here is the low energy tail of the line, on the left of the Γ⅕ exeiton.

physica status solidi (b)•May 1, 1979•1 citation
The absorption coefficient for the two-photon creation of biexciton is calculated for CuCl and wurtzite crystals. Because of the resonance effect only the intermediate lowest optically active excitonic states are taken into account. The absorption coefficient is expressed by a functional of the biexciton envelope. The numerical results are computed with the envelope function of Hylleraas-Ore type (modified and minimized by Brinkman et al). The obtained results for CuCI are in good agreement with absorption measurements published by Gale and Mysyrowicz.
The probability of direct excitation of excitonic molecule in the two-photon absorption process is calculated with an Hylleraas-Ore type biexciton envelope, which is variationally optimized.In the second order of perturbation, because of the resonance effect, only the exciton .r5intermediate state is taken into account.The band structure at band extrema due to spin-orbit interaction is assumed.The transition probability of two-photon absorption is expressed by matrix element between the free exciton and the biexciton envelopes.The obtained probability of two-photon absorption in CuCl is about three orders of magnitude smaller when compared to that obtained by Hauamura.
It is well established that biexcitons can be generated directly by two-photon absorption in CuCI. The intensity dependent nonlinearity arising from this resonance can be used to obtain optical bistability. Recently, Koch and Haug(1) and also Hanamura(2) have predicted the possibility of a bistable operation in a CuCI Fabry-Perot etalon. Hanamura uses a density matrix formalism and predicts that the switching can respond in a picosecond time scale due to the virtual formation of biexcitons. Koch and Haug obtain the complex dielectric function from a Green's function formalism and suggest a bistable behavior for a thin CuCI slab. They use a constant value for the biexciton linewidth, γxx, and a zero value for the exciton linewidth, γx. Their results indicate that a 1-μm-thick CuCI etalon, with natural reflecting surfaces, can give rise to bistability with a switch-on intensity of about 0.1 MW/cm2. The biexciton resonance, however, is located on the tail of the exciton resonance, which acts as a background absorption.
Abstract LO‐phonon‐assisted two‐photon absorption of the first excited level of the excitonic molecule in CuCl is considered on the basis of the previously derived symmetry properties of this state. A giant cross‐section for this process is predicted mainly due to the “resonant” intermediate state Γ 1/5 of the single exciton. The process under consideration overcomes the difficulties of pure two‐photon absorption (TPA) of p‐type envelope states of the excitonic molecule as stated by Hanamura.
Abstract A semiclassical exciton-biexciton model for CuCl is used to obtain the stationary solutions for optical bistability (o.b.) by numerical integration of the second-order Maxwell equation in the limit of large Fresnel numbers. The results obtained from the calculation, which we call exact (ex.), are compared with corresponding numerical results by using the slowly varying envelope approximation (s.v.e.a.) as well as corresponding analytical results obtained by using the mean-field approximation (m.f.a.). The results obtained with the s.v.e.a. are shown to be in close quantitative (within 5%) agreement with the ex. results for each point in the parameter space considered, whereas the m.f.a. gives reasonably good qualitative results only (more than 20% quantitative discrepancy with ex.). Furthermore, o.b. is predicted from these calculations for incident laser field detunings on either side of the two-photon biexciton resonance as well as in the neighbourhood of the resonance. The nonlinearity in the dielectric function that causes o.b. is seen to be very nearly of the Kerr medium type, and consequently, the two-photon biexciton resonance contributes only weakly to the o.b. characteristics.
Abstract Phonon‐assisted two‐photon absorption of biexcitonic levels in CuCl is considered including damping of the nearly resonant excitonic intermediate state. A pronounced structure of the line shape due to resonance effects, threshold effects, and structure in the Fourier transform of the envelope of the excitonic molecule is predicted. A detailed discussion of both temperature and damping effects is given. Large cross sections are predicted. The most favourable energetic range to observe the effects derived here is the low energy tail of the line, on the left of the Γ⅕ exeiton.