Subwavelength dark hollow focus of spirally polarized axisymmetric Bessel-modulated Gaussian beam X. M. Gao, Q.F. Zhan, Q. Wang, M.J. Yun, H.M. Guo and S.L. Zhuang Eur. Phys. J. D, 64 1 (2011) 103-108 Published online: 29 July 2011 DOI: 10.1140/epjd/e2011-10703-6