FiberPol
FiberPol is a compact and cost-effective spectropolarimetric module designed to bring high-precision polarization measurements to existing spectrographs. Built using predominantly commercial off-the-shelf components, FiberPol achieves a polarimetric accuracy of 0.1%—sufficient for a wide range of astrophysical applications, from probing interstellar dust to studying magnetic fields and scattering environments in stars and galaxies.
It has been built to be a front-end system for the long-slit SpUpNIC spectrograph on the SAAO's 1.9m telescope in Sutherland Observatory, South Africa. The system feeds polarization-resolved light into a spectrograph using a carefully arranged bundle of optical fibers, allowing it to operate without major modifications to the host instrument. Its modular design makes it adaptable to different telescope and spectrograph configurations, from small observatories to large facilities like SALT or future 30m-class telescopes.
FiberPol has now been commissioned and is science-ready for point source observations. We have implemented two-channel polarimetry using a dual-fiber configuration, achieving an accuracy of ~0.1–0.2% per 10 nm bin. In the image below, FibePol is shown mounted on the SpUpNIC spectrograph at the South African Astronomical Observatory.