论文标题
在血浆纳米结构附近的四级量子系统中控制非线性光学现象和空间结构的光学效应
Control of nonlinear optical phenomena and spatially structured optical effects in a four-level quantum system near a plasmonic nanostructure
论文作者
论文摘要
我们研究了四级双V型量子系统与一对弱探针场相互作用的非线性光学响应，同时位于二维金属涂层的介电纳米球附近。这样的量子系统包含一个与表面等离子体相互作用的V型子系统，另一个V型子系统与自由空间真空相互作用。所提出的设置的一个独特特征是将其敏感性对施加场的相对相位放置在等离子纳米结构附近时。我们证明，由于存在等离激元纳米结构，因此在另一个探针场作用时，可以对一个激光场之一的三阶（KERR类型）敏感性进行显着修饰。此外，可以通过改变量子系统与等离子纳米结构的距离来控制系统的KERR非线性。我们还表明，可以通过调整所施加场的相对相位来控制此类系统的Kerr非线性。获得的结果可能会在片上纳米级光子设备中找到潜在的应用。我们还研究了一个探针场带有光学涡流而另一个探针场没有涡流的情况下的光 - 物质相互作用。我们证明，由于闭环双V型量子系统的相敏感性，非涡流探针梁的线性和非线性敏感性取决于涡流探针束的方位角角度和轨道角动量（OAM）。此功能在与自由空间真空相互作用的开放四级双V型量子系统中缺少，因为在这种情况下没有量子干扰。我们使用量子系统光敏感性的方位角依赖性来确定空间结构的透射率区域。
We investigate the nonlinear optical response of a four-level double-V-type quantum system interacting with a pair of weak probe fields while located near a two-dimensional array of metal-coated dielectric nanospheres. Such a quantum system contains a V-type subsystem interacting with surface plasmons, and another V-type subsystem interacting with the free-space vacuum. A distinctive feature of the proposed setup is its sensitivity to the relative phase of the applied fields when placed near the plasmonic nanostructure. We demonstrate that due to the presence of the plasmonic nanostructure, the third-order (Kerr-type) susceptibility for one of the laser fields can be significantly modified while another probe field is acting. Moreover, the Kerr nonlinearity of the system can be controlled and even enhanced by varying the distance of the quantum system from the plasmonic nanostructure.We also show that the Kerr nonlinearity of such a system can be controlled by adjusting the relative phase of the applied fields. The results obtained may find potential applications in on-chip nanoscale photonic devices. We also study the light-matter interaction in the case where one probe field carries an optical vortex, and another probe field has no vortex. We demonstrate that due to the phase sensitivity of the closed-loop double V-type quantum system, the linear and nonlinear susceptibility of the nonvortex probe beam depends on the azimuthal angle and orbital angular momentum (OAM) of the vortex probe beam. This feature is missing in open four-level double V-type quantum system interacting with free-space vacuum, as no quantum interference occurs in this case. We use the azimuthal dependence of optical susceptibility of the quantum system to determine the regions of spatially-structured transmittance.
