title: Contrast enhancement in widefield CARS microscopy by tailored phase matching using a spatial light modulator.
abstract: We introduce a widefield CARS microscope implementation that uses a spatial light modulator to obtain extremely precise control over the pump/probe-beam incidence geometry, which provides the possibility to enhance the image contrast at specific target resonances by fine-tuning the incidence angles. We show how this technique can be used to optimize the image contrast between objects of different size and to practically eliminate the undesired signal from the solvent that embeds small target specimens. Changing the numerical aperture of the illumination from 1.27 to 1.24 improved the ratio of the signals of 500 nm polystyrene beads and the agarose solvent by about 20 dB.
authors.affiliation: Division of Biomedical Physics, Innsbruck Medical University, Müllerstraße 44, 6020 Innsbruck, Austria. alexander.jesacher@i-med.ac.at
authors.forename: Alexander
authors.initials: A
authors.lastname: Jesacher
authors.forename: Clemens
authors.initials: C
authors.lastname: Roider
authors.forename: Saranjam
authors.initials: S
authors.lastname: Khan
authors.forename: Gregor
authors.initials: G
authors.lastname: Thalhammer
authors.forename: Stefan
authors.initials: S
authors.lastname: Bernet
authors.forename: Monika
authors.initials: M
authors.lastname: Ritsch-Marte
mesh_terms: D008027:Light; D008853:Microscopy / Q000379:methods*; D008863:Microspheres; D011137:Polystyrenes / Q000737:chemistry; D013059:Spectrum Analysis, Raman
chemical_list: D011137:Polystyrenes