Comparison of intensity distribution of photonic nanojet according to Gaussian beam and radially polarization beam incidence
Comparison of intensity distribution of photonic nanojet according to Gaussian beam and radially polarization beam incidence
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DOI：
10.1016/j.precisioneng.2019.07.019
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
T. Uenohara;Y. Mizutani;Y. Takaya
中科院分区：
文献类型：
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作者：
T. Uenohara;Y. Mizutani;Y. Takaya
光子纳米射流（PNJ）是由介质微球或微圆柱在激光照射下产生的精细光束，已应用于纳米尺度的测量和加工。在本研究中，我们试图通过调整高斯光束和径向偏振光束两束入射激光的强度分布来灵活地控制PNJ的强度分布。时域有限差分仿真结果表明，采用高斯光束可以获得大的PNJ光束直径（1.08 λ），而采用径向偏振光可以获得小的PNJ光束直径（0.34 λ）。此外，通过向微球入射径向偏振光束，可以获得具有各向同性强度分布的PNJ，以及较小的PNJ光束直径。
A photonic nanojet (PNJ) is a fine light beam generated from a dielectric microsphere or microcylinder illuminated by a laser and has been applied to nanometer scale measurement and machining. In this study, we attempt to control the PNJ intensity distribution flexibly by adjusting the intensity distribution of two incident laser beams: a Gaussian beam and a radially polarized beam. Then, finite-difference time-domain simulations demonstrated that a large PNJ beam diameter (1.08 λ) could be obtained by Gaussian beam with a small beam radius, whereas a small PNJ beam diameter (0.34 λ) could be obtained by radially polarized beam. Moreover, PNJ with isotropic intensity distribution can be obtained as well as a small PNJ beam diameter by a radially polarized beam incidence to a microsphere.