  POLICAN is a near-infrared imaging linear polarimeter developed for the
Cananea Near-infrared Camera (CANICA) at the 2.1m telescope of the Guillermo
Haro Astrophysical Observatory (OAGH) located in Cananea, Sonora, Mexico.
POLICAN is mounted ahead of CANICA and consist of a rotating super-achromatic
1-2.7 micron half-wave plate (HWP) as the modulator and a fixed wire-grid
polarizer as the analyzer. CANICA has a 1024 x 1024 HgCdTe detector with a
plate scale of 0.32 arcsec/pixel and provides a field of view of 5.5 x 5.5
arcmin^2. The polarimetric observations are carried out by modulating the
incoming light through different steps of half-wave plate angles 0, 22.5, 45,
67.5 deg, to establish linear Stokes parameters (I, Q, and U). Image reduction
consists of dark subtraction, polarimetric flat fielding, and sky subtraction.
The astrometry and photometric calibrations are performed using the publicly
available data from the Two Micron All Sky Survey. Polarimetric calibration
includes observations of globular clusters and polarization standards available
in the literature. Analysis of multiple observations of globular clusters
yielded an instrumental polarization of 0.51%. Uncertainties in polarization
range from 0.1% to 10% from the brightest 7 mag to faintest 16 mag stars. The
polarimetric accuracy achieved is better than 0.5% and the position angle
errors less than 5 deg for stars brighter than 13 mag in H-band. POLICAN is
mainly being used to study the scattered polarization and magnetic fields in
and around star-forming regions of the interstellar medium.
