title: Experimental and simulation study of the wavelength dependent second harmonic generation of collagen in scattering tissues.
abstract: We report on the wavelength dependence of second harmonic generation (SHG) of collagen in scattering tissues over the wavelength range of 800-1200 nm. The study incorporates inclusion of the molecular hyperpolarizability β of collagen and optical scattering, both of which are wavelength dependent. Using 3D SHG imaging and Monte Carlo simulations, we find the wavelength dependence of β is not well described by a two-state model based on known absorption bands. We further find that longer wavelength excitation is inefficient as the reduction in scattering is overcome by the decreased β far from resonance and the optimal excitation is within the 800-900 nm range. The impact is larger for backward collected SHG.
authors.forename: Gunnsteinn
authors.initials: G
authors.lastname: Hall
authors.forename: Karissa B
authors.initials: KB
authors.lastname: Tilbury
authors.forename: Kirby R
authors.initials: KR
authors.lastname: Campbell
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Eliceiri
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Campagnola
mesh_terms: D000818:Animals; D003094:Collagen; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D051379:Mice; D009010:Monte Carlo Method; D010051:Ovarian Neoplasms / Q000473:pathology; D012542:Scattering, Radiation; D013710:Tendons / Q000166:cytology
chemical_list: D003094:Collagen