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

Quantum Electronics and Laser Science Conference

Femtosecond time-evolution of the coherence properties of resonant secondary emission from excitons in GaAs quantum wells

Michael Woerner, Jagdeep Shah

Published Jan 20, 2003• 0 citations
Publisher

Abstract

Summary form only given. The femtosecond dynamics and the coherence properties of resonant secondary emission (RSE) from quantum wells is a subject of considerable current interest. We use a novel approach in which the sample is resonantly excited by a pair of phase-locked pulses, and the spontaneously emitted radiation is detected by femtosecond upconversion. This novel experimental technique allows us, for the first time, to investigate the temporal evolution and the coherence properties of RSE simultaneously.

DOI
10.1109/qels.1999.807453

Related papers

Resonant Secondary Emission from Two-Dimensional Excitons: Femtosecond Time Evolution of the Coherence Properties

Michael Woerner, Jagdeep Shah

Using a novel technique, we simultaneously study the femtosecond dynamics of the amplitude and the coherence of resonant secondary emission from GaAs quantum wells. Two phase-locked pulses resonantly excite excitons in the semiconductor and the subsequently emitted radiation is detected by femtosecond up-conversion. In experiments at various delays and phases between the excitation pulses we identify three different contributions to the secondary emission with different coherence properties in time.

Physical Review Letters•Nov 9, 1998•71 citations

Coherent control of the temporal evolution of spontaneous emission from excitons in GaAs quantum wells

Michael Woerner, Jagdeep Shah

In a recent paper [1] we have experimentally demonstrated that the coherence properties of resonant secondary emission (RSE) from excitons in quantum wells change distinctly as a function of the elapsed tune after impulsive excitation.

Quantum Optoelectronics•Jan 1, 1999•0 citations

Ultrafast interferometric investigation of resonant secondary emission from quantum well excitons

D. Birkedal, Jagdeep Shah, Loren N. Pfeiffer

Summary form only given. We present the first direct investigation of the coherence properties of resonant secondary emission (RSE) from quantum well excitons. Using ultrafast spectral interferometry, or TADPOLE, we measure spectral fringes that are resonantly enhanced at the exciton transitions. The fringe formation is due to the coherent Rayleigh component of the RSE, and allows us to investigate the dynamics of resonant Rayleigh scattering independent from incoherent luminescence. Our observation of high-contrast spectral fringes is in contradiction with current theories of time resolved resonant Rayleigh scattering from excitons and shows for the first time the non-ergodic nature of the RSE.

Quantum Electronics and Laser Science Conference•Jan 20, 2003•1 citation

Ultrafast secondary radiation of excitons in quantum wells: The transition from the coherent to the incoherent regime

Stefan Haacke, Gary R. Hayes, Robert Anthony Taylor +2 more

Coherent Rayleigh scattering and incoherent luminescence are studied by femtosecond upconversion under resonant excitation as a function of exciton density in GaAs quantum wells. Comparing samples with different well widths allows to establish the relation between inhomogeneous broadening and the shape of resonant Rayleigh scattering. We find an excellent agreement between experiment and a classical model. In samples with moderate inhomogeneous broadening we provide evidence for the transition from coherent to incoherent emission. The comparison with excitonic dephasing times T2 obtained from four-wave-mixing experiments demonstrates that the incoherent exciton population rises within T2/2, at any exciton density when changed by more than an orders of magnitude. The experimental results confirm very clearly the concept predicting that the coherent polarization made up by localized excitons decays into an incoherent exciton population under conservation of the number of excited quanta.

Radiative Processes and Dephasing in Semiconductors•Jan 1, 1998•0 citations

Femtosecond Dynamics and Coherence Properties of Resonant Secondary Emission from Excitons in GaAs Quantum Wells

Michael Woerner, Jagdeep Shah

Springer series in chemical physics•Jan 1, 1998•1 citation

Manifestation of Exciton Coherence in Resonant Quantum Well Emission

N. Garro, Simon Kennedy, R. T. Phillips +2 more

Secondary emission from GaAs quantum wells following resonant pulsed excitation is studied in the time domain. Selective excitation of heavy- and light-hole excitons is accomplished in a two-pulse excitation experiment which preserves sub-ps time resolution. After the initial rise the emission decays exponentially at a fast rate and then with another much slower exponential decay at longer times. The variations in the initial decay times with excitation density and sample temperature are similar to the variation in dephasing rates measured in four-wave mixing experiments. The decay in the visibility of heavy- and light-hole exciton beating is consistent with the decay rates measured for both species separately.

physica status solidi (b)•Sep 1, 1999•3 citations
Summary form only given. The femtosecond dynamics and the coherence properties of resonant secondary emission (RSE) from quantum wells is a subject of considerable current interest. We use a novel approach in which the sample is resonantly excited by a pair of phase-locked pulses, and the spontaneously emitted radiation is detected by femtosecond upconversion. This novel experimental technique allows us, for the first time, to investigate the temporal evolution and the coherence properties of RSE simultaneously.
Using a novel technique, we simultaneously study the femtosecond dynamics of the amplitude and the coherence of resonant secondary emission from GaAs quantum wells. Two phase-locked pulses resonantly excite excitons in the semiconductor and the subsequently emitted radiation is detected by femtosecond up-conversion. In experiments at various delays and phases between the excitation pulses we identify three different contributions to the secondary emission with different coherence properties in time.
Summary form only given. We present the first direct investigation of the coherence properties of resonant secondary emission (RSE) from quantum well excitons. Using ultrafast spectral interferometry, or TADPOLE, we measure spectral fringes that are resonantly enhanced at the exciton transitions. The fringe formation is due to the coherent Rayleigh component of the RSE, and allows us to investigate the dynamics of resonant Rayleigh scattering independent from incoherent luminescence. Our observation of high-contrast spectral fringes is in contradiction with current theories of time resolved resonant Rayleigh scattering from excitons and shows for the first time the non-ergodic nature of the RSE.
Coherent Rayleigh scattering and incoherent luminescence are studied by femtosecond upconversion under resonant excitation as a function of exciton density in GaAs quantum wells. Comparing samples with different well widths allows to establish the relation between inhomogeneous broadening and the shape of resonant Rayleigh scattering. We find an excellent agreement between experiment and a classical model. In samples with moderate inhomogeneous broadening we provide evidence for the transition from coherent to incoherent emission. The comparison with excitonic dephasing times T2 obtained from four-wave-mixing experiments demonstrates that the incoherent exciton population rises within T2/2, at any exciton density when changed by more than an orders of magnitude. The experimental results confirm very clearly the concept predicting that the coherent polarization made up by localized excitons decays into an incoherent exciton population under conservation of the number of excited quanta.
Secondary emission from GaAs quantum wells following resonant pulsed excitation is studied in the time domain. Selective excitation of heavy- and light-hole excitons is accomplished in a two-pulse excitation experiment which preserves sub-ps time resolution. After the initial rise the emission decays exponentially at a fast rate and then with another much slower exponential decay at longer times. The variations in the initial decay times with excitation density and sample temperature are similar to the variation in dephasing rates measured in four-wave mixing experiments. The decay in the visibility of heavy- and light-hole exciton beating is consistent with the decay rates measured for both species separately.