NIRC2 Polarimetry (NIRC2-Pol, or nirc2p) is a dual-channel polarimetry mode on the Keck II NIRC2 infrared imager. It enables polarimetric observations in JHKL’ bands in combination with multiple existing NIRC2 modes, such as grism spectroscopy and high-contrast coronagraphic imaging, and both NGS and LGS AO. This document presents full technical details of the mode, including instructions for its calibration and on-sky usage.
Publication Date: 2026-06-17