Coherent scattering in multi-harmonic light microscopy.
By focusing a pulsed laser beam into a sample, harmonic up-conversion can be generated as well as multi-photon excited fluorescence. Whereas multi-photon excited fluorescence microscopy is well established, the use of multi-harmonic generation for three-dimensional image contrast is very recent. Both techniques can provide similar resolution and, for adequate radiating source density, comparable signal levels, allowing them to be combined in a single versatile instrument. However, harmonic generation differs fundamentally from fluorescence generation in that it is coherent and produces radiation patterns that are highly sensitive to phase. As such, multi-harmonic generation microscopy provides a unique window into molecular spatial organization that is inaccessible to fluorescence.
Laboratoire de Neurophysiologie INSERM EPI 00-02, ESPCI, Paris, France.
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Moreaux
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Charpak
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Blanchard-Desce
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D000818:Animals; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure*; D005456:Fluorescent Dyes; D006624:Hippocampus / Q000166:cytology / Q000502:physiology; D066298:In Vitro Techniques; D007834:Lasers; D008027:Light; D008856:Microscopy, Fluorescence / Q000379:methods*; D017966:Pyramidal Cells / Q000166:cytology* / Q000502:physiology; D011726:Pyridinium Compounds; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity
D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; C048153:4-(6-(4-dibutylaminophenyl)-1,3,5-hexatrienyl)-1-(4'-sulfobutyl)pyridinium