Activity: Talk or presentation › Oral presentation
We study frequency-resolved femtosecond pump-probe reflectivity of a planar at GaAs-AlAs microcavity. About 8 ps after a pump pulse, we observe a strong excess probe reflectivity. Light trapped in the cavity accumulates a phase change due to a time-dependent refractive index, resulting in a change in frequency by more than 5 linewidths away from the cavity resonance. The frequency change is non-adiabatic as the electromagnetic field distribution changes shape in time and the rate of change of the cavity resonance is fast. An analytical model predicts dynamics in agreement with experiments, and points to crucial parameters that control future applications.