We developed a polarimeter for the near-infrared camera SIRIUS mounted on the IRSF 1.4 m telescope in South Africa. The polarimeter, SIRPOL, consists of an achromatic (1-2.5 micron) wave plate rotator unit and a polarizer located upstream of the camera, both of which are at a room temperature. This minimizes the effect of the mirrors in the camera on instrumental polarization. The combination of the polarimeter with the SIRIUS camera enables a deep (J=19.2 mag, 5 sigma in one hour) and wide-field (7.7' x 7.7') imaging polarimetry at JHKs simultaneously. The three color near-infrared polarimetry is useful for understanding the properties of dust grains that cause scattering and absorption in various environments (e.g., star forming regions, late-type stars, and galaxies). Using IRSF and SIRPOL, wide-field near-infrared polarization surveys in various star-forming regions are being conducted, starting from 2006, which aim to study both reflection nebulae associated with young stars and interstellar polarizations of background stars.

• 2013.08.26: Website renewal.
• 2006.12.17: IRSF/SIRPOL Circular Polarization Mode First Light!
• 2005.12.25: IRSF/SIRPOL Linear Polarization Mode First Light!

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