Rabi oscillations and self-induced transparency in InAs/InP quantum dot semiconductor optical amplifier operating at room temperature

Abstract

We report direct observations of Rabi oscillations and self-induced transparency in a quantum dot optical amplifier operating at room temperature. The experiments make use of pulses whose durations are shorter than the coherence time which are characterized using Cross-Frequency-Resolved Optical Gating. A numerical model which solves the Maxwell and Schrödinger equations and accounts for the inhomogeneously broadened nature of the quantum dot gain medium confirms the experimental results. The model is also used to explain the relationship between the observability of Rabi oscillations, the pulse duration and the homogeneous and inhomogeneous spectral widths of the semiconductor.

Nonlinear pulse propagation in InAs/InP quantum dot optical amplifiers: Rabi oscillations in the presence of nonresonant nonlinearities

“…The present model extends our previous models of coherent light-matter interactions 2,4 . The electromagnetic field is assumed to propagate as a TEM mode along the Z-axis of the amplifier, which is modeled in turn as a cascade of ensembles of quantummechanical two-level systems, expressing the inhomogeneous spectral broadening of the self-assembled QD medium.…”

Coherent control in a semiconductor optical amplifier operating at room temperature

“…The experimental results can be modelled qualitatively considering that the SOA behaves as an effective ensemble of two-level systems. Describing the semiconductor medium as sequentially placed two-level systems, which are fed incoherently from a carrier reservoir, has been used to describe propagation of short pulses along a quantum cascade laser 28 and in inhomogeneously broadened self-assembled quantum dashes 18 and quantum dots 20 . The model calculates the coevolution of the electromagnetic field and the electronic wavefunctions along the propagation axis according to the coupled Maxwell and Schrödinger equations for every time iteration using the density matrix formalism (see ref.…”

“…However, a proper quantitative description of the dephasing process requires invoking the inhomogeneous broadened version of the Maxwell-Schrödinger model 20 .…”

“…Following the demonstrations of Rabi oscillations in a quantum dash amplifier 18 , the observations were repeated in zerodimensional quantum systems, as reported for an InP based quantum dot SOA operating at 1,550 nm (ref. 20) and in a 1,300-nm GaAs quantum dot amplifier 21 .…”

Ultrafast optical properties of lithographically defined quantum dot amplifiers

“…2 Recently, coherent pulse shaping has been confirmed in QD amplifiers up to room temperature. 3 The unique zero-dimensional density of states in the QD active region is responsible for these properties, allowing for reduced linewidth enhancement factor and broad gain bandwidth, 4 along with fast refilling of carriers from excited states. So far, all of this progress have been made with QDs fabricated by the self-assembly (Stranski-Krastanov) growth process.…”