光学学报, 2014, 34 (1): 0114004, 网络出版: 2014-01-02
不同数值孔径下调控矢量光束聚焦场的反向构建
Backward Focus Engineering with Controlled Cylindrical Vector Beams under Different Numerical Apertures
激光光学 矢量光束 数值孔径 光针场 光管场 laser optics vectorial beam numerical aperture optical needle field optical tube field
摘要
根据电磁辐射理论和矢量光场积分理论,研究了矢量光束聚焦场特性与聚焦透镜数值孔径之间的关系。在透镜焦场区设定电偶极子阵列和磁偶极子阵列,收集其辐射场并反向聚焦,通过调控与优化偶极子阵列参数,反演不同数值孔径透镜下的聚焦光场,获得了聚焦光针场、三维衍射受限光管场随透镜数值孔径的变化规律。研究结果表明,随着数值孔径的减小,光针场的纵向分量纯度、边缘斜率以及光针长度递减,半峰全宽递增,光管场依旧保持纯方位角偏振分布,且中空区域的半峰全宽递增。研究结果对在不同数值孔径下矢量光束聚焦的应用研究具有重要意义。
Abstract
Based on the electro-magnetic radiation theory and the optical vector field integral theory, the relation between the property of optical vector focal fields and the numerical aperture has been studied. The electric and magnetic dipoles arrays are located along the optical axis in the focal volume. The radiation fields of them are collected and focused reversely. By manipulating and optimizing the dipole parameters and reversing the focused optical field with different numerical apertures, we study the rule of the optical needle and diffraction limited three-dimensional optical tube changing with the numerical aperture. The results show that the longitudinal polarization component purity, the edge slope and optical needle length decline with the decrease of numerical aperture and the full-width at half-maximum increases. The optical tube field is still azimuthally polarized with an intensity null at the center. The length of the intensity null along radial direction will increase. The research has significance on the application of focused vector beam under different numerical apertures.
刘雪宁, 王吉明, 赫崇君, 刘友文. 不同数值孔径下调控矢量光束聚焦场的反向构建[J]. 光学学报, 2014, 34(1): 0114004. Liu Xuening, Wang Jiming, He Chongjun, Liu Youwen. Backward Focus Engineering with Controlled Cylindrical Vector Beams under Different Numerical Apertures[J]. Acta Optica Sinica, 2014, 34(1): 0114004.