A4 Refereed article in a conference publication
DIPOL-2: a double image high precision polarimeter
Authors: V. Piirola, A. Berdyugin, Svetlana Berdyugina
Editors: Ramsay S. K., McLean I. S., Takami H.
Conference name: SPIE. Astronomical Telescopes and Instrumentation
Publication year: 2014
Journal: Proceedings of SPIE : the International Society for Optical Engineering
Book title : Ground-based and Airborn Instrumentation for Astronomy V
Volume: 9147
Number of pages: 9
ISSN: 0277-786X
DOI: https://doi.org/10.1117/12.2055923(external)
We have built a new broad-band polarimeter (DIPOL-2), capable of measuring polarization with the precision at the 10-5 level. Two dichroic beam-splitters are used to split light into three passbands (BVR), simultaneously recorded with three CCDs. A rotatable superachromatic lambda/2 (or lambda/4) plate is used as the polarization modulator and a plane parallel calcite plate as the polarization analyzer. Simple yet effective design with small number of optical elements and moving mechanical parts makes DIPOL-2 a highly versatile and reliable instrument with negligible instrumental polarization, very well suitable for observations with remotely controlled telescopes. Current and planned observing programs are briefly described.