The excitation of the giant dipole resonance induced by fusion reaction is
studied with N/Z asymmetry in the entrance channel. The time dependent Hart
ree-Fock solution exhibits a strong dipole vibration which can be associate
d with a giant vibration along the main axis of the deformed compound nucle
us. This dipole motion appears to be nonlinearly coupled to the shape oscil
lation, leading to a strong modulation of its frequency. These phenomena ca
n be detected in the gamma-ray emission from hot compound nuclei.