Rabi oscillations of ultrashort optical pulses in 1.55 μm InGaAs/InGaAsP quantum-well amplifiers

Using the Foreman effective mass Hamiltonian for InxGa1-xAs/InyGa1-yAszP1-z quantum wells, the propagation of a 150 fs pulse in an optical amplifier was calculated by solving the wave equation with the computed polarization as a source term. The multisubband carrier dynamics and heating as well as the polarization dynamics were taken into account. The intensity of the propagated pulse as well as its imposed frequency chirp, the carrier density, and temperature show strong Rabi oscillations. The Rabi oscillation imposes negative frequency chirp, redshifting the frequency components of a propagating pulse and thus its spectrum, as a result of the gain saturation-induced self-phase modulation. (C) 2004 American Institute of Physics.