Error analysis of a Stokes imaging polarimeter based on liquid crystal variable retarders

Ivan Montes-González; Neil C. Bruce

doi:10.1117/12.2629706

29 August 2022 Error analysis of a Stokes imaging polarimeter based on liquid crystal variable retarders

Ivan Montes-González, Neil C. Bruce

Proceedings Volume 12184, Ground-based and Airborne Instrumentation for Astronomy IX; 121846F (2022) https://doi.org/10.1117/12.2629706
Event: SPIE Astronomical Telescopes + Instrumentation, 2022, Montréal, Québec, Canada

Conference Poster

Abstract

In many astrophysical processes, the complete characterization of the polarization properties of radiation gives important information about the source or the interaction between radiation and matter. Stokes imaging polarimeters based on liquid crystal variable retarders (LCVRs) are widely used to determine the polarization state of radiation. But these devices have errors due to the nature of the liquid crystals that induce an inhomogeneous retardance over the complete aperture, and their fast-axis position depends on the applied voltage. We present the analysis of the impact of variations in the retardance and orientation of the LCVRs, in the optimization of a Stokes imaging polarimeter. An optimized Stokes polarimeter based on two LCVRs, was simulated. First considering individual errors in the retardance and orientation, then one million cases were simulated adding random errors in both LCVRs. The condition number was calculated to analyze the effect in the optimization of the polarimeter. Also, a Stokes imaging polarimeter was calibrated, to verify experimentally the effect of these errors in a real polarimeter. For the calibration the instrument matrix and condition number were calculated individually in every pixel of the image. The results show that these errors lead to polarimetric measurements different from the ideal and to a poorly optimized polarimeter, demonstrating that a condition number optimization of the instrument matrix and a calibration are not sufficient to guarantee accurate polarimetric measurements.

Citation Download Citation

Ivan Montes-González and Neil C. Bruce "Error analysis of a Stokes imaging polarimeter based on liquid crystal variable retarders", Proc. SPIE 12184, Ground-based and Airborne Instrumentation for Astronomy IX, 121846F (29 August 2022); https://doi.org/10.1117/12.2629706

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available