Title
Design of the life signature detection polarimeter LSDpol
Author
Keller, Christoph U. (Universiteit Leiden)
Snik, Frans (Universiteit Leiden)
Patty, C. H.Lucas (Universiteit Leiden; University of Bern)
Klindzic, D. (TU Delft Astrodynamics & Space Missions; Universiteit Leiden)
Krasteva, Mariya (Universiteit Leiden)
Doelman, David S. (Universiteit Leiden)
Wijnen, T.P.G. (TU Delft Astrodynamics & Space Missions; Universiteit Leiden) 
Pallichadath, V. (TU Delft Astrodynamics & Space Missions)
Stam, D.M. (TU Delft Astrodynamics & Space Missions)
Contributor
Lystrup, Makenzie (editor)
Perrin, Marshall D. (editor)
Date
2020
Abstract
Many biologically produced chiral molecules such as amino acids and sugars show a preference for left or right handedness (homochirality). Light reflected by biological materials such as algae and leaves therefore exhibits a small amount of circular polarization that strongly depends on wavelength. Our Life Signature Detection polarimeter (LSDpol) is optimized to measure these signatures of life. LSDpol is a compact spectropolarimeter concept with no moving parts that instantaneously measures linear and circular polarization averaged over the field of view with a sensitivity of better than 10-4. We expect to launch the instrument into orbit after validating its performance on the ground and from aircraft. LSDpol is based on a spatially varying quarter-wave retarder that is implemented with a patterned liquid-crystal. It is the first optical element to maximize the polarimetric sensitivity. Since this pattern as well as the entrance slit of the spectrograph have to be imaged onto the detector, the slit serves as the aperture, and an internal field stop limits the field of view. The retarder's fast axis angle varies linearly along one spatial dimension. A fixed quarter-wave retarder combined with a polarization grating act as the disperser and the polarizing beam-splitter. Circular and linear polarization are thereby encoded at incompatible modulation frequencies across the spectrum, which minimizes the potential cross-talk from linear into circular polarization.
Subject
Biosignatures
Circular polarization
Earth
Exoplanets
Homochirality
Polarimetry
Spectropolarimetry
To reference this document use:
http://resolver.tudelft.nl/uuid:b7481dd5-ccf4-422d-9a54-3a600a5777df
DOI
https://doi.org/10.1117/12.2562656
Publisher
SPIE
ISBN
9781510636736
Source
Space Telescopes and Instrumentation 2020: Optical, Infrared, and Millimeter Wave, 11443
Event
Space Telescopes and Instrumentation 2020: Optical, Infrared, and Millimeter Wave, 2020-12-14 → 2020-12-22, Virtual, Online, United States
Series
Proceedings of SPIE - The International Society for Optical Engineering, 0277-786X, 11443
Part of collection
Institutional Repository
Document type
conference paper
Rights
© 2020 Christoph U. Keller, Frans Snik, C. H.Lucas Patty, D. Klindzic, Mariya Krasteva, David S. Doelman, T.P.G. Wijnen, V. Pallichadath, D.M. Stam, More Authors