Wang Haotian, Zhang Jianing, Wu Xiang, Shen Deyuan
Opt Express. 2019 Apr 15;27(8):10472-10481. doi: 10.1364/OE.27.010472.
We present an optical-trapping scheme based on an on-resonance photonic nanojet (PNJ) excited using a plane wave. A two-dimensional numerical simulation demonstrates that a PNJ is enhanced through resonance with whispering gallery modes (WGMs) and achieves a larger spatial distribution, providing a stable trapping region for nanoparticles nearly four times larger than those of the WGM nodes without broadening by the PNJ. To further enlarge the trapping region, an asymmetric micro-resonator lengthens the mode field of the on-resonance PNJ. We also propose an effective method for addressing the nanoparticle-induced resonance detuning through exciting high-order WGMs of a larger-mode field volume.
我们提出了一种基于平面波激发的共振光子纳米射流（PNJ）的光阱方案。二维数值模拟表明，PNJ通过与回音壁模式（WGM）共振得到增强，并实现了更大的空间分布，为纳米粒子提供了一个稳定的捕获区域，该区域比WGM节点的捕获区域大近四倍，且不会因PNJ而展宽。为了进一步扩大捕获区域，一个不对称微谐振器延长了共振PNJ的模式场。我们还提出了一种有效的方法，通过激发更大模式场体积的高阶WGM来解决纳米粒子引起的共振失谐问题。
