title: Circularly polarized coherent anti-Stokes Raman scattering microscopy.
abstract: We demonstrate circularly polarized coherent anti-Stokes Raman scattering (CP-CARS) microscopy that significantly suppresses the nonresonant background for high-contrast vibrational imaging. Circularly polarized pump and Stokes fields with opposite handedness are used to excite CARS signal. In this case, theoretically the nonresonant CARS signal and resonant CARS signal from isotropic media will completely vanish, while the resonant CARS signal from anisotropic structures can still exist. This allows CARS imaging of anisotropic samples with enhanced resonant contrast. Furthermore, we performed CP-CARS imaging on fibroin fibers from silkworm silk, and the results confirmed its effectiveness in background suppression.
authors.affiliation: Department of Physics, Faculty of Science, National University of Singapore, Singapore 117542.
authors.forename: Paul Kumar
authors.initials: PK
authors.lastname: Upputuri
authors.forename: Jian
authors.initials: J
authors.lastname: Lin
authors.forename: Li
authors.initials: L
authors.lastname: Gong
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Liu
authors.forename: Haifeng
authors.initials: H
authors.lastname: Wang
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Huang
mesh_terms: D005349:Fibroins / Q000737:chemistry; D008853:Microscopy / Q000379:methods*; D008863:Microspheres; D055620:Optical Phenomena; D011137:Polystyrenes / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D011137:Polystyrenes; D005349:Fibroins