Adiabatically driven electron dynamics in a resonant photonic band gap: Optical switching of a Bragg periodic semiconductor

The adiabatic driving of the resonant electron dynamics in a one-dimensional resonant photonic band gap is proposed as an optical mechanism for nonlinear ultrafast switching. Pulsed excitation inside the photonic gap results in an ultrafast suppression and recovery of the gap. This behavior results from the adiabatic carrier dynamics due to rapid radiative damping inside the band gap.

Figure 1

Reflected and transmitted pulse shapes for increasing intensity. With increasing intensity the transmission increases and envelope modulations due to Rabi oscillations occur. All pulses are normalized to the respective input pulses maxima.

Figure 2

Electron density in the first, 100th, and last (200th) QW for different incident field strengths. For nonlinear excitation, the system dynamics occur simultaneously with the pulse envelope. For strong excitation $\left(8\pi \right)$, the populations exhibit Rabi oscillations.

Figure 3

Spectra of pump pulses located at different energies with respect to the excitonic resonance are used to investigate the influence of the induced carrier dynamics on a weak probe pulse.

Figure 4

Integrated probe pulse reflection: A pump pulse $\left(1\pi \right)$ inside or above the photonic band gap suppresses the photonic band gap. The gap recovers on the time scale of the pump pulse when excited inside the photonic band gap. For excitation above the gap it does not recover for nanoseconds. Top, theoretical calculations. Bottom, measurements (Ref. 2) with a $4\mu \mathrm{J}$, FWHM 1.6 ps pulse.