A scheme comparison of Autler–Townes based slow light in inhomogeneously broadened quantum dot media

Abstract

We propose a method to achieve significant optical signal delays exploiting the effect of AutlerTownes splitting in an inhomogeneously broadened quantum dot medium. The absorption and slow-down effects are compared for three schemes i.e. Ξ, V and Λ, corresponding to different excitation configurations. Qualitative differences of the V-scheme compared to the Ξ-and Λ-scheme are found, which show that features of Autler-Townes splitting are only revealed in the V-scheme. The underlying physical mechanisms causing this discrepancy are analyzed and discussed. Finally we compare field propagation calculations of the schemes showing significantly larger achievable signal delays for the V-scheme despite finite absorption of the coupling field. This opens the possibility for using waveguide structures for both coupling and probe fields, thus significantly increasing the achievable signal delays.

Group-velocity slowdown in a double quantum dot molecule

“…The dephasing of the quantum coherence in the QD molecule obtained from our microscopic calculation at and above 150 K is still quite a bit slower than the dephasing rate 0.125 ns −1 assumed in a recent AMO-like calculation of EIT based slow-light in single QDs. 28 Such a slow dephasing along with lifetime-limited linewidths, which were also assumed in Ref. 28, are generally only realized at very low temperatures.…”

“…28 Such a slow dephasing along with lifetime-limited linewidths, which were also assumed in Ref. 28, are generally only realized at very low temperatures.…”

Investigation of coherent molecular resonances in quantum dot–metallic nanoparticle systems using their spontaneous emission

“…[51] that showed inclusion of band anisotropy could make such transition possible via mixing of the states, shape asymmetry, and permanent dipole moment [52,53]. Additionally, under the influence of an electric field parity conservation can also be relaxed to some extent, allowing the 1S h to 1P e transition to happen [54].…”

“…Therefore, to solve the optical Bloch equations we considered the relaxation decay rate of such excitons (Γ inter ) is 1/1.7 ns À 1 and μ 12 ¼ 0.1 e  nm [49,54]. We also consider its dephasing broadening (γ 21 ) is 3.3 ns À 1 and ω 12 ¼ ω l , i.e., the pump field is resonant with the 1-2 transition [46].…”

Slow light between two absorbing resonance in asymmetry double quantum dots

“…Recently, slow light attractive for the delay line has been studied widely in the quantum dots (QDs) systems. Most early work is based on electromagnetically induced transparency (EIT) [1][2][3][4][5][6][7][8]. The QDs homogeneous line width [1,2], inhomogeneous broadening [1,5,6,8], many-body interactions [3], size and geometry [4] dependence on the slow light properties of QDs is studied.…”