  We present the results of a high-time resolution polarization study of single
pulses from pulsars B0950+08 and B1642-03. Single pulses from pulsar B0950+08
sometimes show isolated micropulses without any significant associated subpulse
emission. Assuming that the properties of such micropulses represent the
intrinsic nature of micropulse emission, we characterize the width and
polarization properties of these `intrinsic' microstructures. Most of the
`intrinsic' micropulses (~90%) follow common characteristic polarization
properties, while the average width of these micropulses is consistent with the
general micropulse population from this pulsar. Single pulses from these
pulsars show a diverse range of polarization properties, including
depolarization and mixing of two orthogonal modes resulting in polarization
position angle jumps. We present a superposition model of the two orthogonal
modes which can explain depolarization, the observed position angle jumps, and
associated changes in other polarization parameters.
