  We study the effect of weak lensing by cosmic (super-)strings on the
anisotropies of cosmic microwave background (CMB). In developing a method to
calculate the lensing convergence field due to strings, and thereby temperature
and polarization angular power spectra of CMB, we clarify how the nature of
strings, characterized by the intercommuting probability, can influence these
CMB anisotropies. Assuming that the power spectrum is dominated by
Poisson-distributed string segments, we find that the convergence spectrum
peaks at low multipoles and is mostly contributed from strings located at
relatively low redshifts. As the intercommuting probability decreases, the
spectra of the convergence and hence the lensed temperature and polarizations
are gained because the number density of string segments becomes larger. An
observationally important feature of the string-induced CMB polarizations is
that the string-lensed spectra decay more slowly on small scales compared with
primordial scalar perturbations from standard inflation.
