Detection of circular polarization in light scattered from photosynthetic microbes.

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TitleDetection of circular polarization in light scattered from photosynthetic microbes.
Publication TypeJournal Article
Year of Publication2009
AuthorsSparks, WB, Hough, J, Germer, TA, Chen, F, DasSarma, S, DasSarma, P, Robb, FT, Manset, N, Kolokolova, L, Reid, N, F Macchetto, D, Martin, W
JournalProc Natl Acad Sci U S A
Date Published2009 May 12
KeywordsBacteria, Chlorophyll, Equipment Design, Exobiology, Extraterrestrial Environment, Light, Optics and Photonics, Photosynthesis, Plant Leaves, Refractometry, Scattering, Radiation, Synechococcus

The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in the search for life elsewhere in the universe. A candidate universal biosignature is homochirality, which is likely to be a generic property of all biochemical life. Because of the optical activity of chiral molecules, it has been hypothesized that this unique characteristic may provide a suitable remote sensing probe using circular polarization spectroscopy. Here, we report the detection of circular polarization in light scattered by photosynthetic microbes. We show that the circular polarization appears to arise from circular dichroism of the strong electronic transitions of photosynthetic absorption bands. We conclude that circular polarization spectroscopy could provide a powerful remote sensing technique for generic life searches.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID19416893
PubMed Central IDPMC2674403