The tight focusing properties of Laguerre-Gaussian-correlated Schell-model beams
The tight focusing properties of Laguerre-Gaussian-correlated Schell-model beams
复制标题
拉盖尔高斯相关谢尔模型光束的紧聚焦特性
DOI：
10.1080/09500340.2016.1151565
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发表时间：
2016
影响因子：
1.3
通讯作者：
Huang Wei
中科院分区：
文献类型：
--
作者：
Xu Hua-Feng;Zhang Zhou;Qu Jun;Huang Wei
基于Richards-Wolf矢量衍射理论，详细研究了高数值孔径（NA）聚焦系统中laguerre - gaussian -相关Schell-model （LGSM）光束的紧密聚焦特性，包括光强分布、偏振度和相干度。研究发现，LGSM光束表现出与GSM光束不同的特殊聚焦特性，这种紧密聚焦特性与初始空间相干度和模序密切相关。通过选择合适的初始空间相干度值，LGSM光束可在焦平面上形成椭圆形焦斑、圆形焦斑或甜甜圈形暗空心光束，且暗空心光束的中心暗尺寸随模阶的增加而增大。此外，还详细分析了初始空间相干度和模序对偏振度和相干度的影响。我们的研究结果可能在光捕获中得到应用。
Based on the Richards–Wolf vectorial diffraction theory, the tight focusing properties, including the intensity distribution, the degree of polarization and the degree of coherence, of the Laguerre–Gaussian-correlated Schell-model (LGSM) beams through a high-numerical-aperture (NA) focusing system are investigated in detail. It is found that the LGSM beam exhibits some extraordinary focusing properties, which is quite different from that of the GSM beam, and the tight focusing properties are closely related to the initial spatial coherenceand the mode ordern. The LGSM beam can form an elliptical focal spot, a circular focal spot or a doughnut-shaped dark hollow beam at the focal plane by choosing a suitable value of the initial spatial coherence, and the central dark size of the dark hollow beam increases with the increase of the mode ordern. In addition, the influences of the initial spatial coherenceand the mode ordernon the degree of polarization and the degree of coherence are also analysed in detail, respectively. Our results may find applications in optical trapping.