Design of the life signature detection polarimeter LSDpol

Keller, Christoph U.; Snik, Frans; Patty, Lucas; Klindžic, Dora; Krasteva, Mariya; Doelman, David S.; Wijnen, Thomas; Pallichadath, Vidhya; Stam, Daphne M.; Demory, Brice-Olivier; Kühn, Jonas G.; Hoeijmakers, H. Jens; Pommerol, Antoine; Poch, Olivier (2020). Design of the life signature detection polarimeter LSDpol. In: Space Telescopes and Instrumentation 2020: Optical, Infrared, and Millimeter Wave. Online Only, United States. 2020/12/14 - 2020/12/18. 10.1117/12.2562656

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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.

Item Type:

Conference or Workshop Item (Paper)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences
08 Faculty of Science > Physics Institute
10 Strategic Research Centers > Center for Space and Habitability (CSH)
08 Faculty of Science > Physics Institute > NCCR PlanetS

UniBE Contributor:

Patty, Lucas; Demory, Brice-Olivier; Kühn, Jonas Guillaume; Hoeijmakers, Herman Jens and Pommerol, Antoine

Subjects:

500 Science
500 Science > 520 Astronomy
500 Science > 530 Physics
600 Technology > 620 Engineering

ISBN:

9781510636743

Series:

SPIE

Language:

English

Submitter:

Danielle Zemp

Date Deposited:

15 Apr 2021 14:11

Last Modified:

18 Apr 2021 03:03

Publisher DOI:

10.1117/12.2562656

BORIS DOI:

10.48350/154690

URI:

https://boris.unibe.ch/id/eprint/154690

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