Propagation dynamics of a wavepacket through an optical cavity

We experimentally investigate propagation dynamics of a wavepacket through a high finesse optical cavity. Narrow-band and quasi-percussional excitations of a cavity field by a wavepacket are studied. When the spectral width of an incident wavepacket is narrowed compared with the cavity linewidth, the transmitted pulse is adiabatically followed the time evolution of the incoming pulse. For the quasi-percussional excitation of very short pulse in time, the cavity is excited on the time duration of the incoming pulse. The falling edge of the wavepacket loses its original information and experiences a characteristic decay determined by the intracavity photon lifetime. The measured time delay of the pulse peak, in contrast to the constant delay predicted, greatly depends on the pulse width of the incoming wavepacket. We also examine the cavity high-reflected transient spike of optical precursors at the excitation of a step-modulated pulse. The experimental results show a very good agreement with a simple theoretical calculation.