title: Harnessing the point-spread function for high-resolution far-field optical microscopy.
abstract: The resolution limit of far-field optical microscopy is reexamined with a full vectorial theoretical analysis. A highly symmetric excitation optical field and optimized detection scheme are proposed to harness the total point-spread function for a microscopic system. Spatial resolution of better than 1/6λ is shown to be obtainable, giving rise to a resolution better than 100 nm with visible light excitation. The experimental measurement is applied to examine nonfluorescent samples. A lateral resolution of 1/5λ is obtained in truly far-field optical microscopy with a working distance greater than ∼500λ. Comparison is made for the far-field microscopic measurement with that of a nearfield scanning optical microscopy, showing that the proposed scheme provides a better image quality.
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Xiangsheng
authors.initials: X
authors.lastname: Xie
authors.affiliation: Key Lab of Numerical Controlled Technology, Guangdong Polytechnic Normal University, Guangzhou 510635, China.
authors.forename: Yongzhu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Ken
authors.initials: K
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Jianying
authors.initials: J
authors.lastname: Zhou