title: A large-field polarisation-resolved laser scanning microscope: applications to CARS imaging.
abstract: Laser-scanning imaging techniques are frequently used to probe the molecule spatial orientation in a sample of interest by exploiting selection rules depending on the polarisation of the excitation light. For the successful implementation of these techniques the precise control of the polarisation at the sample level is of fundamental importance. Polarisation distortions induced by the optical elements are often the main limitation factor for the maximum size of the field-of-view in polarisation-resolved (PR) laser-scanning microscopy, since for large scanning angles the polarisation distortions may mask the real sample structure. Here we shall demonstrate the implementation of large-field-of-view PR microscopy and show PR CARS imaging of mouse spinal cord thanks to a careful design of the laser-beam optical path. We shall show that this design leads to strongly suppressed distortions and quantify their effects on the final images. Although the focus of this work is on CARS imaging, we stress that the approaches described here can be successfully applied to a wide range of PR laser-scanning techniques.
authors.affiliation: Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, I-56127, Pisa, Italy.|NEST, Scuola Normale Superiore, I-56127, Pisa, Italy.
authors.forename: G
authors.initials: G
authors.lastname: DE Vito
authors.affiliation: Experimental Neurology Unit, Department of Surgery and Translational Medicine, University of Milan-Bicocca, Monza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Canta
authors.affiliation: Experimental Neurology Unit, Department of Surgery and Translational Medicine, University of Milan-Bicocca, Monza, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Marmiroli
authors.affiliation: Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, I-56127, Pisa, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Piazza
mesh_terms: D000818:Animals; D007834:Lasers; D051379:Mice; D018613:Microscopy, Confocal / Q000295:instrumentation* / Q000379:methods*; D013059:Spectrum Analysis, Raman; D013131:Spine / Q000648:ultrastructure
keywords: Coherent Anti-Stokes Raman Scattering; RP-CARS; large field-of-view; laser-scanning imaging; polarisation-resolved