Systems design, assembly, integration and lab testing of WALOP-South Polarimeter
Paper i proceeding, 2024

Wide-Area Linear Optical Polarimeter (WALOP)-South is the first wide-field and survey-capacity polarimeter in the optical wavelengths. On schedule for commissioning in 2024, it will be mounted on the 1 m SAAO telescope in Sutherland Observatory, South Africa to undertake the PASIPHAE sky survey. PASIPHAE program will create the first polarimetric sky map in the optical wavelengths, spanning more than 2000 square degrees of the southern Galactic region. In a single exposure, WALOP-South's innovative design will enable it to measure the linear polarization (Stokes parameters q and u) of all sources in a field of view (FoV) of 35 × 35 arc-minutes-squared in the SDSS-r broadband and narrowband filters between 500-750 nm with 0.1 % polarization accuracy. The unique goals of the instrument place very stringent systems engineering goals, including on the performance of the optical, polarimetric, optomechanical, and electronic subsystems. In particular, the major technical hurdles for the project included the development of: (a) an optical design to achieve imaging quality PSFs across the FoV, (b) an optomechanical design to obtain high accuracy optical alignment in conjugation with minimal instrument flexure and stress birefringence on optics (which can lead to variable instrumental polarization), and (c) an on-sky calibration routine to remove the strong polarimetric cross-talk induced instrumental polarization to obtain 0.1% across the FoV. All the subsystems have been designed carefully to meet the overall instrument performance goals. As of May 2024, all the instrument optical and mechanical subsystems have been assembled and are currently getting tested and integrated. The complete testing and characterization of the instrument in the lab is expected to be completed by August 2024. While the instrument was initially scheduled for commissioning in 2022, it got delayed due to various technical challenges; WALOP-South is now on schedule for commissioning in second half of 2024. In this paper, we will present (a) the design and development of the entire instrument and its major subsystems, focusing the instrument's opto-mechanical design which has not been reported before, and (b) assembly and integration of the instrument in the lab and early results from lab characterization of the instrument's optical performance.

stellar polarization

WALOP

imaging polarimetry

wide field camera

polarization

PASIPHAE

polarimetry

linear polarimetry

optical polarimeter

Författare

S. Maharana

Idryma Technologias kai Erevnas (FORTH)

Inter-University Centre for Astronomy and Astrophysics

South African Astronomical Observatory

A. N. Ramaprakash

Inter-University Centre for Astronomy and Astrophysics

California Institute of Technology (Caltech)

Idryma Technologias kai Erevnas (FORTH)

Chaitanya Rajarshi

Inter-University Centre for Astronomy and Astrophysics

Pravin Khodade

Inter-University Centre for Astronomy and Astrophysics

Bhushan Joshi

Inter-University Centre for Astronomy and Astrophysics

Pravin Chordia

Inter-University Centre for Astronomy and Astrophysics

Abhay Kohok

Inter-University Centre for Astronomy and Astrophysics

R. M. Anche

Inter-University Centre for Astronomy and Astrophysics

University of Arizona

Deepa Modi

South African Astronomical Observatory

J. A. Kypriotakis

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

Amit Deokar

Inter-University Centre for Astronomy and Astrophysics

Aditya Kinjawadekar

Inter-University Centre for Astronomy and Astrophysics

S. B. Potter

South African Astronomical Observatory

University of Johannesburg

D. Blinov

Saint Petersburg State University - Spsu

Idryma Technologias kai Erevnas (FORTH)

Panepistimio Kritis

H. K. Eriksen

Universitetet i Oslo

M. Falalaki

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

Hitesh Gajjar

South African Astronomical Observatory

T. Ghosh

National Institute of Science Education and Research

E. Gjerløw

Universitetet i Oslo

Sebastain Kiehlmann

Idryma Technologias kai Erevnas (FORTH)

Panepistimio Kritis

I. Liodakis

Idryma Technologias kai Erevnas (FORTH)

Panepistimio Kritis

N. Mandarakas

Idryma Technologias kai Erevnas (FORTH)

Panepistimio Kritis

Georgia Virginia Panopoulou

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

V. Pavlidou

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

T. J. Pearson

California Institute of Technology (Caltech)

V. Pelgrims

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

Université libre de Bruxelles (ULB)

A. C.S. Readhead

California Institute of Technology (Caltech)

Idryma Technologias kai Erevnas (FORTH)

R. Skalidis

California Institute of Technology (Caltech)

Konstantinos Tassis

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

Namita Uppal

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

I. K. Wehus

Universitetet i Oslo

Proceedings of SPIE - The International Society for Optical Engineering

0277786X (ISSN) 1996756X (eISSN)

Vol. 13096 130967P
9781510675155 (ISBN)

Ground-Based and Airborne Instrumentation for Astronomy X 2024
Yokohama, Japan,

Ämneskategorier

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

DOI

10.1117/12.3016144

Mer information

Senast uppdaterat

2024-10-15