Determination of oscillator strength of confined excitons in a semiconductor microcavity

• Main Authors: E.A. Cotta, P.M.S. Roma
• Format: Article
• Language: English
• Published: Institute for Condensed Matter Physics 2014-06-01
• Series: Condensed Matter Physics
• Subjects: microcavity; Rabi-splitting; polariton; oscillator-strength; strong coupling; reflectance
• Online Access: http://dx.doi.org/10.5488/CMP.17.23702

We have achieved a significant experimental Rabi-splitting (3.4 meV) for confined polaritons in a planar semiconductor λ microcavity for only a single quantum well (SQW) of GaAs (10 nm) placed at the antinode. The Rabi-splitting phenomena are discussed in detail based on the semiclassical theory, where two coupled harmonic oscillators (excitons and photons) are used to describe the system. In this way, we can obtain the dispersion curve of polaritons, the minimum value for the cavity reflectance and the oscillator strength to reach the strong coupling regime. This approach describes an ensemble of excitons confined in a SQW and includes a dissipation component. The results present a weak coupling regime, where an enhanced spontaneous emission takes place, and a strong coupling regime, where Rabi-splitting in the dispersion curve can be observed. The theoretical results are confronted with experimental data for the reflectance behavior in resonant and off-resonant conditions and present a great accuracy. This allows us to determine the oscillator strength of the confined excitons in the SQW with great precision.