We propose a method to obtain nano-scale 3D super-resolution in STED fluorescence microscopy. A double-ring-shaped cylindrical vector vortex beam, with an appropriate vortex angle and a proper truncation parameter of the beam, is used to generate a 3D dark spot as the erase spot. A single-ring-shaped radially polarized beam is used as a pump beam, which can generate a sharper 3D bright spot. The volume of the generated 3D dark spot is small and the uniformity of the light wall surrounding the spot is quite high. Consequently, the 3D super-resolution ability of a STED microscope is improved and nano-scale three-dimensional resolutions are obtained.
1. Kaplan, A., N. Friedman, and N. Davidson, "Optimized single-beam dark optical trap," J. Opt. Soc. Am. B, Vol. 19, 1233-1238, 2002. doi:10.1364/JOSAB.19.001233
2. Isenhower, L., W. Williams, A. Dally, and M. Saffman, "Atom trapping in an interferometrically generated bottle beam trap," Opt. Lett., Vol. 34, 1159-1161, 2009. doi:10.1364/OL.34.001159
3. Watanabe, T., Y. Iketaki, T. Omatsu, K. Yamamoto, M. Sakai, and M. Fujii, "Two-point-separation in super-resolution fluores-cence microscope based on up-conversion fluorescence depletion technique," Opt. Express, Vol. 11, 3271-3276, 2003. doi:10.1364/OE.11.003271
5. Lotito, V., U. Sennhauser, C. V. Hafner, and G.-L. Bona, "Interaction of an asymmetric scanning near field optical microscopy probe with °uorescent molecules," Progress In Electromagnetics Research, Vol. 121, 281-299, 2011. doi:10.2528/PIER11091703
6. Liao, C.-C. and Y.-L. Lo, "Phenomenological model combining dipole-interaction signal and background effects for analyzing modulated detection in apertureless scanning near-field optical microscopy," Progress In Electromagnetics Research, Vol. 112, 415-440, 2011.
7. Di Donato, A., A. Morini, and M. Farina, "Optical fiber extrinsic micro-cavity scanning microscopy," Progress In Electromagnetics Research,, Vol. 133, 347-366, 2013.
8. Zhang, Y., B. Ding, and T. Suyama, "Trapping two types of particles using a double-ring-shaped radially polarized beam," Phys. Rev. A, Vol. 81, 023831, 2010. doi:10.1103/PhysRevA.81.023831
9. Zhang, Y. and J. Bai, "Improving the recording ability of a near-field optical storage system by higher-order radially polarized beams," Opt. Express, Vol. 17, 3698-3706, 2009. doi:10.1364/OE.17.003698
10. Zhang, Y., Y. Okuno, and X. Xu, "Theoretical study of optical recording with a solid immersion lens illuminated by focused double-ring-shaped radially polarized beam," Opt. Commun., Vol. 282, 4481-4488, 2009. doi:10.1016/j.optcom.2009.08.031
11. Ozeri, R., L. Khaykovich, and N. Davidson, "Long spin relaxation times in a single-beam blue-detuned optical trap," Phys. Rev. A, Vol. 59, R1750-R1753, 1999. doi:10.1103/PhysRevA.59.R1750
12. Bokor, N. and N. Davidson, "Tight parabolic dark spot with high numerical aperture focusing with a circular π phase plate," Opt. Commun., Vol. 270, 145-150, 2007. doi:10.1016/j.optcom.2006.09.022
13. Moser, T., H. Glur, V. Romano, F. Pigeon, O. Parriaux, M. A. Ahmed, and T. Graf, "Polarization-selective grating mirrors used in the generation of radial polarization," Appl. Phys. B, Vol. 80, 707-713, 2005. doi:10.1007/s00340-005-1794-5
14. onezawa, K., Y. Kozawa, and S. Sato, "Generation of a radially polarized laser beam by use of the birefringence of a c-cut Nd:YVO4 crystal," Opt. Lett., Vol. 31, 2151-2153, 2006. doi:10.1364/OL.31.002151
15. Youngworth, K. S. and T. G. Brown, "Focusing of high numerical aperture cylindrical-vector beams," Opt. Express, Vol. 7, 77-87, 2000. doi:10.1364/OE.7.000077
16. Sahar, E. and D. Treves, "Excitation singlet-state absorption in dyes and their effect on dyes lasers," IEEE J. Quntum Electronics, Vol. 13, 962-967, 1977. doi:10.1109/JQE.1977.1069258
17. Westphal, V. and S. W. Hell, "Nanoscale resolution in the focal plane of an optical microscope," Phy. Rev. Lett., Vol. 94, 143903, 2005. doi:10.1103/PhysRevLett.94.143903
18. Harke, B., J. Keller, C. K. Ullal, V. Westphal, A. Schonle, and S. W. Hell, "Resolution scaling in STED microscopy," Opt. Express, Vol. 16, 4154-4162, 2008. doi:10.1364/OE.16.004154