  We experimentally investigate the effects of phase noise on the resonant and
non-resonant dynamics of the atom-optics kicked rotor. Employing sinusoidal
phase modulation at various frequencies, resonances are found corresponding to
periodic phase shifts, resulting in the effective transformation of quantum
anti-resonances into resonances and vice-versa. The stability of the resonance
is analysed, with the aid of experiments, epsilon-classical theory and
numerical simulations, and is found to be surprisingly robust against phase
noise. Finally we look into the effects of phase noise on dynamical
localization and discuss the destruction of the localization in terms of
decoherence.
