We describe the design and performance of a spectropolarimetric instrument, called TreePol, that is dedicated to remote sensing of the circular polarization signatures due to homochirality in photosynthetic organisms. To ensure high polarimetric sensitivity to observe such signatures, we combine rapid modulation offered by a Ferroelectic Liquid Crystal with a dual-beam spectrometer that incorporates fast line-detectors. The latter also furnishes relatively short measurement times through spectral multiplexing. We introduce several mitigation steps to correct for potential cross-talk from much stronger linear polarization signals into the measured circular polarization spectra. We present first laboratory results for (decaying) leaves and microbes, and we provide an outlook for field-work. In addition to providing a unique look into chiral photosystems of life on Earth, we aim to pave the way towards a unique detection method for extraterrestrial life.

Date Published: 19 September 2017
PDF
Proc. SPIE 10407, Polarization Science and Remote Sensing VIII, 1040710 (19 September 2017); doi: 10.1117/12.2273361

Published in SPIE Proceedings Vol. 10407:
Polarization Science and Remote Sensing VIII
Joseph A. Shaw; Frans Snik, Editor(s)