We study the time-resolved reflectivity spectrum of a switched planar GaAs-AlAs microcavity. Between 5 and 40 ps after the switching (pump) pulse, we observe a strong excess probe reflectivity and a change of the frequency of light trapped in the cavity up to 5 linewidths away from the cavity resonance. This frequency change does not adiabatically follow the fast-changing cavity resonance. The frequency change is attributed to an accumulated phase change due to the time-dependent refractive index. An analytical model predicts dynamics in qualitative agreement with the experiments, and points to crucial parameters that control future applications.

J. Opt. Soc. Am. B
Ultrafast Spectroscopy

Harding, P.J, Bakker, H.J, Hartsuiker, A, Claudon, J, Mosk, A.P, Gérard, J.-M, & Vos, W.L. (2012). Observation of a stronger-than-adiabatic change of light trapped in an ultrafast switched GaAs-AlAs microcavity. J. Opt. Soc. Am. B, 29(2), 1–5. doi:10.1364/JOSAB.29.0000A1