Polaritonic frequency-comb generation and breather propagation in a negative-index metamaterial with a cold four-level atomic medium

We develop a concept for a waveguide that exploits spatial control of nonlinear surface-polaritonic waves. Our scheme includes an optical cavity with four-level N-type atoms in a lossless dielectric placed above a negative-index metamaterial layer. We propose exciting a polaritonic Akhmediev breather at a certain position of the interface between the atomic medium and the metamaterial by modifying laser-field intensities and detunings. Furthermore, we propose generating position-dependent polaritonic frequency combs by engineering widths of the electromagnetically induced transparency window commensurate with the surface-polaritonic modulation instability. Therefore, this waveguide acts as a high-speed polaritonic modulator and position-dependent frequency-comb generator, which can be applied to compact photonic chips.

我们提出了一种波导的概念，该波导利用了对非线性表面极化激元波的空间控制。我们的方案包括一个光腔，在负折射率超材料层上方放置的无损电介质中有四能级N型原子。我们提出通过改变激光场强度和失谐，在原子介质和超材料之间的界面的特定位置激发极化激元阿赫梅迪耶夫呼吸子。此外，我们提出通过设计与表面极化激元调制不稳定性相称的电磁诱导透明窗口的宽度来产生位置相关的极化激元频率梳。因此，这种波导可作为高速极化激元调制器和位置相关的频率梳发生器，可应用于紧凑型光子芯片。