  The connection between the time-dependent physical spectrum of light and the
phase space overlap of Wigner functions is investigated for optical pulses.
Time and frequency properties of optical pulses with chirp are analyzed using
the phase space Wigner and Ambiguity distribution functions. It is shown that
optical pulses can exhibit interesting phenomena, very much reminiscent of
quantum mechanical interference, quantum entanglement of wave packets, and
quantum sub-Planck structures of the time and frequency phase space.
