| Stimulated Emission Depletion (STED) microscope system is set up in this paper, theory of STED microscope is systematic studied and problems in our STED microscope system have been solved. Modification of STED beam has been realized by simulation and experiment. In experiment, modification procedure from laser spot to doughnut-shape STED beam is presented by CCD photos. Overlap of the excited beam and STED beam also presented by CCD photos.Simulations of five polarizations with different phase plates are done. Firstly, four polarizations with 0-2n vortex phase plate modulated, the result indicated that 0-2π vortex phase plate only can modulated circular polarized laser beam for STED system. Secondly, five polarizations with two combined phase plates are modulated, the result indicated that STED beam modulated with combined of two phase plates can generated laser patterns, which have compress in three directions. But these patterns enlarged the dark hole in its center, which will decrease the resolution of STED system. High NA objective and higher intensity could reduce dark hole of the patterns. Besides several valuable beams with nano patterns such as hollow rhombus, bottle and semilunar shaped are acquired. A kind method of generate doughnut-shaped laser pattern by linear polarized laser is required.With a home-made doughnut-shaped CW laser writing system, nano-pillar array is fabricated. Firstly, experimental conditions are acquired by 405nm laser, experiment results indicated that diameter of nano-pillar will reduce by the increase of laser intensity. Second, experiment is carry out by 532nm laser, which has better beam quality than 405nm laser. A kind of 125nm nanopillar array has been experimentally achieved, the size has break the optical diffraction. Relationship of laser power with diameter of nano-pillar is studied. Thirdly, Micro-nano composite is acquired by home-made doughnut-shaped CW laser writing system. |
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