Spatial fluorescence cross-correlation spectroscopy by means of a spatial light modulator

Author(s): Yoann Blancquaert, Jie Gao, Jacques Derouard, Antoine Delon

Abstract:

“Spatial fluorescence cross-correlation spectroscopy is a rarely investigated version of fluorescence correlation spectroscopy, in which the fluorescence signals from different observation volumes are cross-correlated. In the reported experiments, two observation volumes, typically shifted by a few µm, are produced, with a spatial light modulator and two adjustable pinholes. We illustrated the feasibility and potentiality of this technique by: i) measuring molecular flows, in the range 0.2-1.5 µm/ms, of solutions seeded with fluorescent nanobeads or rhodamine molecules (simulating active transport phenomenons); ii) investigating the permeability of the phospholipidic membrane of giant unilamellar vesicles versus hydrophilic or hydrophobic molecules (in that case the laser spots were set on both sides of the membrane). Theoretical descriptions are proposed together with a discussion about fluorescence-correlation-spectroscopy-based, alternative methods.”

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Publication: Journal of Biophotonics
Issue/Year: Journal of Biophotonics, Volume 1 Issue 5, Pages 408 – 418 (2008)
DOI: 10.1002/jbio.200810007

Applications of LCoS-based adaptive optical elements in microscopy

Author(s): Andreas Hermerschmidt, Jan Haffner, Tobias Haist, Wolfgang Osten

Abstract:

“Liquid crystal on silicon (LCoS)-based spatial light modulators (SLMs) are versatile adaptive optical elements. In microscopy, among their applications are aberration sensing and correction in wide-field microscopy and also the implementation of holographic optical tweezers. For aberration correction, the required scene-based wavefront sensing can be implemented as a modified correlation-based Shack-Hartmann approach where a high-resolution SLM first senses and then corrects the aberrations. For the implementation of holographic optical tweezers, the SLM serves as a variable optical beam-splitter which is addressed with holograms computed by fast algorithms implemented on the graphics processing unit (GPU) of a common PC almost in real-time.”

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Publication: Proceedings IEEE/LEOS Internationall Conference on Optical MEMs and Nanophotonics
Issue/Year: Proceedings IEEE/LEOS Internationall Conference on Optical MEMs and Nanophotonics, 2008,
DOI: 10.1109/OMEMS.2008.4607842