Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Sci Rep. 2013;3:2337. doi: 10.1038/srep02337.
We propose and theoretically investigate a model to realize cascaded optical nonlinearity with few atoms and photons in one-dimension (1D). The optical nonlinearity in our system is mediated by resonant interactions of photons with two-level emitters, such as atoms or quantum dots in a 1D photonic waveguide. Multi-photon transmission in the waveguide is nonreciprocal when the emitters have different transition energies. Our theory provides a clear physical understanding of the origin of nonreciprocity in the presence of cascaded nonlinearity. We show how various two-photon nonlinear effects including spatial attraction and repulsion between photons, background fluorescence can be tuned by changing the number of emitters and the coupling between emitters (controlled by the separation).
我们提出并理论研究了一个在一维（1D）中使用少量原子和光子实现级联非线性的模型。我们系统中的光学非线性是由光子与二能级发射器（如原子或量子点）的共振相互作用介导的，这些发射器位于一维光子波导中。当发射器具有不同的跃迁能量时，波导中的多光子传输是非互易的。我们的理论提供了对级联非线性存在时非互易性起源的清晰物理理解。我们展示了如何通过改变发射器的数量和发射器之间的耦合（由分离控制）来调整各种双光子非线性效应，包括光子之间的空间吸引和排斥、背景荧光。
