首次提出圆顶轴棱锥这一新型光学元件. 由衍射理论分析了平面波通过圆顶轴棱锥后的光场强度分布, 用软件对光强分布进行仿真. 结果表明, 平行光通过圆顶轴棱锥后可以形成多个局域空心光束 (bottle beam), 由于球面波能量在焦点附近高度集中, 所得的 bottle beam在焦点附近强度极大. 通过仿真对比得知用圆顶轴棱锥产生的 bottle beam的暗域周围光强远大于用两束Bessel光束干涉所得, 大幅度提高了 bottle beam囚禁粒子的效率. 通过比较这两种方法产生的 bottle beam对粒子囚禁的散射力, 证实了圆顶轴棱锥产生 bottle beam在粒子囚禁方面更具优势.
A novel optical element, vaulted axicon, is proposed for the first time in this paper. We analyze the distribution of light field with diffraction theory, and simulate the intensity distribution behind vaulted axicon. The result shows that multi-bottle beam can be obtained after a plane wave has passed through an vaulted axicon, moreover the intensity of the bottle beam is very high in the focal region because of the energy of spherical wave is significant concentrated in this region. The simulation and comparison show that the intensity around the bottle beam generated by vaulted axicon is far higher than that generated by superposition of two Bessel beams, therefore the particle trapping efficiency can be significantly increased. By comparing the scattering forces of bottle beam generated by the two methods, we demonstrate that the bottle beam generated by vaulted axicon is superior in particle trapping.