Influence of incident beam polarization on intensity and polarization distributions of tight focusing spot. (January 2015)

• Record Type: Journal Article
• Authors: Li, Qinggele; Ledoux-Rak, Isabelle; Lai, Ngoc Diep
• Is Part Of: Advanced device materials. Volume 1:Number 1(2015)
• Page Start: 4
• Page End: 10
• Publication Date: 2015-01
• Subjects: Polarization -- Point spread function -- Imaging system -- Confocal microscopy -- Microfabrication; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1179/2055031614Y.0000000002
• Languages: English
• ISSNs: 2055-0308

Abstract

Abstract : We demonstrated theoretically and experimentally the influence of polarization of an input light beam on the intensity and polarization distributions of a tight focusing spot, obtained by a high numerical aperture (NA) objective lens (OL). The numerical calculations, based on vectorial Debye theory, show that, under tight focusing condition (NA = 1.4), the shape of the focusing spot varies as a function of the input beam polarization, resulting in either asymmetric or symmetric spots. A home made confocal microscope constituted by a high NA OL is employed to scan the fluorescence image of single gold nanoparticles showing the actual polarization dependence of focusing spot. The input linear polarization allows generating a small but asymmetric focusing spot, while the circular polarization produces a larger but symmetric one.