TY - JOUR

T1 - WALOP-South

T2 - A four-camera one-shot imaging polarimeter for PASIPHAE survey. Paper I-optical design

AU - Maharana, Siddharth

AU - Kypriotakis, John A.

AU - Ramaprakash, Anamparambu N.

AU - Rajarshi, Chaitanya

AU - Anche, Ramya M.

AU - Shrish,

AU - Blinov, Dmitry

AU - Eriksen, Hans Kristian

AU - Ghosh, Tuhin

AU - Gjerløw, Eirik

AU - Mandarakas, Nikolaos

AU - Panopoulou, Georgia V.

AU - Pavlidou, Vasiliki

AU - Pearson, Timothy J.

AU - Pelgrims, Vincent

AU - Potter, Stephen B.

AU - Readhead, Anthony C.S.

AU - Skalidis, Raphael

AU - Tassis, Konstantinos

AU - Wehus, Ingunn K.

N1 - Publisher Copyright: © 2021 Society of Photo-Optical Instrumentation Engineers (SPIE).

PY - 2021/3/9

Y1 - 2021/3/9

N2 - The Wide-Area Linear Optical Polarimeter (WALOP)-South instrument will be mounted on the 1-m South African Astronomical Observatory telescope in South Africa as part of the Polar-Areas Stellar Imaging Polarization High Accuracy Experiment (PASIPHAE) program to carry out a linear imaging polarization survey of the Galactic polar regions in the optical band. Designed to achieve polarimetric sensitivity of 0.05% across a 35 × 35 arc min field of view (FOV), it will be capable of measuring the Stokes parameters I, q, and u in a single exposure in the R broadband and narrowband filters between 0.5 to 0.7 μm. For each measurement, four images of the full field corresponding to linear polarization angles of 0 deg, 45 deg, 90 deg, and 135 deg in the instrument coordinate system will be created on four detectors from which the Stokes parameters can be found using differential photometry. In designing the optical system, major challenges included correcting for the dispersion introduced by large split angle Wollaston prisms used as analysers and other aberrations from the entire field to obtain imaging quality point spread function (PSF) at the detector. We present the optical design of the WALOP-South instrument which overcomes these challenges and delivers near seeing limited PSFs for the entire FOV.

AB - The Wide-Area Linear Optical Polarimeter (WALOP)-South instrument will be mounted on the 1-m South African Astronomical Observatory telescope in South Africa as part of the Polar-Areas Stellar Imaging Polarization High Accuracy Experiment (PASIPHAE) program to carry out a linear imaging polarization survey of the Galactic polar regions in the optical band. Designed to achieve polarimetric sensitivity of 0.05% across a 35 × 35 arc min field of view (FOV), it will be capable of measuring the Stokes parameters I, q, and u in a single exposure in the R broadband and narrowband filters between 0.5 to 0.7 μm. For each measurement, four images of the full field corresponding to linear polarization angles of 0 deg, 45 deg, 90 deg, and 135 deg in the instrument coordinate system will be created on four detectors from which the Stokes parameters can be found using differential photometry. In designing the optical system, major challenges included correcting for the dispersion introduced by large split angle Wollaston prisms used as analysers and other aberrations from the entire field to obtain imaging quality point spread function (PSF) at the detector. We present the optical design of the WALOP-South instrument which overcomes these challenges and delivers near seeing limited PSFs for the entire FOV.

KW - linear polarimetry

KW - one-shot polarimetry

KW - optical polarization

KW - polarization

KW - wide-field polarimeter

KW - Wollaston prisms

UR - http://www.scopus.com/inward/record.url?scp=85103695207&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/c020699e-da27-3416-9b38-ee36f8e26890/

U2 - 10.1117/1.JATIS.7.1.014004

DO - 10.1117/1.JATIS.7.1.014004

M3 - Article

AN - SCOPUS:85103695207

VL - 7

JO - Journal of Astronomical Telescopes, Instruments, and Systems

JF - Journal of Astronomical Telescopes, Instruments, and Systems

SN - 2329-4124

IS - 1

M1 - 014004

ER -