title: Imaging of director fields in liquid crystals using stimulated Raman scattering microscopy.
abstract: We demonstrate an approach for background-free three-dimensional imaging of director fields in liquid crystals using stimulated Raman scattering microscopy. This imaging technique is implemented using a single femtosecond pulsed laser and a photonic crystal fiber, providing Stokes and pump frequencies needed to access Raman shifts of different chemical bonds of molecules and allowing for chemically selective and broadband imaging of both pristine liquid crystals and composite materials. Using examples of model three-dimensional structures of director fields, we show that the described technique is a powerful tool for mapping of long-range molecular orientation patterns in soft matter via polarized chemical-selective imaging.
authors.affiliation: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Taewoo
authors.initials: T
authors.lastname: Lee
authors.forename: Haridas
authors.initials: H
authors.lastname: Mundoor
authors.forename: Derek G
authors.initials: DG
authors.lastname: Gann
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Callahan
authors.forename: Ivan I
authors.initials: II
authors.lastname: Smalyukh
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007834:Lasers; D050866:Liquid Crystals / Q000737:chemistry* / Q000528:radiation effects*; D008422:Materials Testing; D008853:Microscopy / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*