  We extend the concept of radially and azimuthally polarized optical beams to
the polychromatic domain by introducing cylindrically polarized nondiffracting
optical pulses. In particular, we discuss in detail the case of cylindrically
polarized X-waves, both in the paraxial and nonparaxial regime. The explicit
expressions for the electric and magnetic fields of cylindrically polarized
X-waves is also reported.
