  We present experimental techniques and results related to the optimization
and characterization of our nanofiber-based atom trap [Vetsch et al., Phys.
Rev. Lett. 104, 203603 (2010)]. The atoms are confined in an optical lattice
which is created using a two-color evanescent field surrounding the optical
nanofiber. For this purpose, the polarization state of the trapping light
fields has to be properly adjusted. We demonstrate that this can be
accomplished by analyzing the light scattered by the nanofiber. Furthermore, we
show that loading the nanofiber trap from a magneto-optical trap leads to
sub-Doppler temperatures of the trapped atomic ensemble and yields a
sub-Poissonian distribution of the number of trapped atoms per trapping site.
