Creation of Sub-diffraction Longitudinally Polarized Spot by Focusing Radially Polarized Light with Binary Phase Lens

• DOI: 10.1038/srep38859
• Publication Date: 2016-12-12T10:59:56Z
• Authors: An-ping Yu; Gang Chen; Zhi-hai Zhang; Zhong-quan Wen; Lu-ru Dai; Kun Zhang; Sen-lin Jiang; Zhi-xiang Wu; Yu-yan Li; Chang-tao Wang; Xian-gang Luo
• Keywords: Through-the-lens metering

Abstract The generation of a sub-diffraction longitudinally polarized spot is great interest in various applications, such as optical tweezers, super-resolution microscopy, high-resolution Raman spectroscopy, and high-density data storage. Many theoretical investigations have been conducted into the tight focusing with high-numerical-aperture aplanatic lenses combination filters. Optical super-oscillation provides new approach to light beyond diffraction limit. Here, we propose planar binary phase lens experimentally demonstrate focal by radially light. has numerical aperture 0.93 long length 200λ for wavelength λ = 632.8 nm, generated full-width-at-half-maximum about 0.456λ, which smaller than limit, 0.54λ. A 5λ-long needle size also observed near designed point.